Demystifying the RC Valve || Inspecting and Adjusting - CORRECTLY!

[@hotsauce3700]

Brilliant video and thank you. Can you do a video on disassembly and cleaning of the valve/flappers?

[@brian.d.mobley]

Thanks so much Hot Sauce!! I did do one as part of a top end rebuild. The valve in this vid was from an 07 CR125 so its a newer style flap valve. The difference between the Honda RC valves is not super different so if this one is not exactly like yours, look at a place like Rocky Mountain ATV's microfiche to see the differences. They are mostly similar. Here is a link to the other vid. If you get stuck, message me on Instagram. kzbin.info/www/bejne/l3quloCfq5mCaa8

[@TheMotorOlazx]

Great video! Love how you show all pros and cons from the other techniques also. Will watch all your two stroke videos. Thanks from Sweden

[@brian.d.mobley]

Hey Motor Olazx! Thank you for watching! I love to read where the viewers call home. I think you are the first to comment from Sweden!

[@jasonwolfe5861]

The RC valve on my 2006 CR 125 doesn't have cables. How do I adjust it?

[@brian.d.mobley]

Hi Jason. Luckily, you don’t. Its mechanical.

[@bigos.motoowens5813]

I’m having to watch this several times. I can’t seem to get all the slack out of the cable. It is way to long on the backside

[@brian.d.mobley]

All the slack won’t come out. Some slack is normal as the servo is grommet mounted.

[@brian.d.mobley]

I was in a rush when I replied earlier so I wanted to explain a little better. If you use the HRC method, you are setting the back cable to open no more than needed and not "over-rotate" the valve as illustrated in the video. Because of this, there will be a little slack in the rear cable that will be taken up as the servo rotates. The setting you are hoping to achieve is that, as the servo rotates, it does not rotate past the point where the top of the flap valve and the top of the exhaust port are in the same plane or are aligned. I hope that explains things a little better.

[@dirtfreek]

Just finished rebuilding the motor on my 03, this is a very informative video that makes me feel confident that I have my cables set up correctly. I had planned to follow the 12mm method as noted by the previous owner of my bike but I'm glad I found this video of yours, Thank You!!

[@brian.d.mobley]

HI DirtFreek. Thanks! Its a shame the factory manual doesnt explain the whole process better. Im really glad that the video helped you and thank you so much for watching and taking the time to comment.

[@labbe001]

I bought a 2002 CR250 brand new when they first hit the dealerships. It is still my primary bike that I ride to this day. I have done the 12MM adjustment no less then 100 times over the past 18 or so years. Never again. Thank you so much for posting this video. I feel like I've found the golden egg....lol.

[@brian.d.mobley]

Hey David. I know that technique is super popular, but that gap really means nothing. The goal on the rear adjuster is proper preload. Thats it. If that preload was achieved at 10mm, great. If it was achieved at 9mm, also great. The gap means nothing. Not to mention the unnecessary strain on the servo motor. Broken gear teeth on that motor is a COMMON problem and I would bet (but cant confirm) that its from pulling down so hard on that servo motor when people employ that popular "12mm" technique. Imagine basing your throttle range on how tight the throttle cable was. That means nothing! What matter is that the throttle is closed when its "relaxed" and that its fully open when it completely rotated. Thats all that the throttle does! Same with the RC Cable rear adjuster. I think the only reason the 12mm technique became so popular is because the manual is so fuzzy and it provided an easy "answer" to the confusing manual. The manual is actually pretty close, but its just not described well. Anyway, Im going on far too long! Glad it helped you and thank you for watching!

[@brian.d.mobley]

BTW, I own a 2002 CR250 also! Its so pretty, I hardly ride it! HAHA!

[@PowerEagleUSA]

Thank you for doing this video and clearing this up! Much appreciated :)

[@brian.d.mobley]

Hey Power Eagle USA! Love the patriotic handle! Really glad you liked it. It was a BIG project to make it. Lots of research. Interviewed a lot of well known mechanics (most of whom really couldnt explain the process either!). And the filming and editing took a long time too. So, Im glad you liked it and I hope it helps lots of people out there.

[@RhinoStar0]

So you didnt run it to show the valve action. I think the servo doesn't care about your white line. I think the potentiometer is a crude encoder that keeps track of the postition of the servo with the linear increase in voltage as it rotates, the ECU uses this information to figure out the position of the servo and then knows where the servo is and in which direction to turn it according to engine rpm and TPS position. When I have time I will take my oscilloscope down to the garage, swap the 3 year old fuel in the tank with fresh fuel and probe those wires while the bike is running. That should clear it up for me at least. Also that spring does not return the valve to its closed position, I think you kind of proved that to yourself when you rotated the valve by hand to the open position and it just stayed there, until you manually returned it to the closed position, the spring is there so you can attached the cables, try attaching two solid cables with no spring over that short distance.

[@brian.d.mobley]

You make some good points. The manual describes the “cable adjustment is done via the servo motor and spring.” Honestly, I am considering doing a new version of this video clarifying that further. I don’t think I did as good of a job as I should have, in retrospect. But, making a video is a tremendous undertaking - not an excuse - just saying. As for not running the motor, I didn’t. I had other assembly left to do at the time this was posted and I was also concerned about not making the video too long as it was pretty long as it is. I do not have an oscilloscope, but I would be curious to see what you find. Perhaps what you learn from that i could incorporate into an updated version of this video.

[@brian.d.mobley]

Looking for that oscilloscope data still...

[@furocity]

Honda service manual calls it a “Radical combustion” system so now I’m really confused on the real name haha

[@brian.d.mobley]

Hey 2 Many! That’s a new one to me!

[@apachechief6583]

Best video so far thanks for the tips.

[@brian.d.mobley]

Thanks !!! I am glad you found it useful!

[@kaelslivers]

Just bought a 2004 cr 125. Got the bike about a week ago and thought the whole rpm range felt pretty weak. Spent way too much time messing with the cables and following your steps. It completely brought the bike back to life. Thanks for the video👍🏼

[@brian.d.mobley]

Hey Karl! That’s awesome! I love to know I was able to help someone!

[@jimmadonna1436]

Brian, I'm going to decarbonizing my RC EXHAUST VALUES. I plan to use easy off oven cleaner and I can't find your service video on this. Do you have one? Thanks!

[@brian.d.mobley]

Hey Jim. I didnt show the dirty part of scrubbing the flap valves, but here is where I discussed the cleaning. Thank you for watching! kzbin.info/www/bejne/l3quloCfq5mCaa8

[@jimmadonna1436]

@@brian.d.mobley Thank you for getting back to me this quickly, I appreciate it! I'll check it out, again thanks.

[@brian.d.mobley]

@@jimmadonna1436 My pleasure! Glad to help!

[@mhengler27]

On the front adjustment, It looks like the “sheath”? The black part of the cable? Is still moving up a down when you stop tightening it. So just adjust it till there isn’t any movement?

[@brian.d.mobley]

Yes! Sorry if that wasn’t obvious. I’ve actually been considering reshooting a few parts of that video to have better focus and explain things a little better.

[@logandavis4607]

Thanks for the great video !! Will all this work good with a 04 cr 125 ?

[@brian.d.mobley]

Hey Logan! Sooo.... This is my level of knowledge on that! I have never personally done this procedure on the unicorn 04 CR125! BUT, I have helped two people with it and they report that they were able to do the same procedure effectively on their '04's. You should know that the cables are not interchangeable between a 250 and a 125. Hope that helps!

[@pleenc30]

Totally logical when you think about it - similar to the YPVS system back in the day, just needed some care and an eye for then the valve is at its most open state. Very helpful thank you.

[@brian.d.mobley]

Hey@P Lee! I felt the same after I learned of this technique developed by HRC. It seemed logical to me too. A bit more work, but you only have to do it once.

[@shoot-to-film]

very valuable info. i had it adjusted to the 12mm method and the cable was bent and hard to turn the servo, too much tension. that way just seemed wrong without even running the bike. so i kept searching and found this vid, i will go with the factory honda method for sure. Thanks.

[@brian.d.mobley]

Hey Kai! I have found the same. From my experience, 12mm has always resulted in an overly taut cable.

[@fegaroporta]

Hello mr Mobley, ur last youtube vid on the rc valve was realy good but i missed a little detail in the end , on adjusting the right cable you say turn the pulley counterclockwize and then make sure that the flap in the cylinder is flush with the opening, but... you dont mention if you turn the servo motor by hand at its full stop counterclock wize so you can then sync the cable regulators to match the flap when the servo its on its full stop counterclockwize with the rc flap to be open to the prefered gap. Can you clear this up for me please? Thanx

[@brian.d.mobley]

Hey @fegaroporta. The short answer is that the servo doesnt have any kind of stopping mechanism or function. As you can see in the video, it will rotate continuously in either direction depending on the polarity of the power input. Under power, the servo only pulls the rear cable in a counterclockwise rotation. The spring on the front cable is the return mechanism which brings the pulley to rest against the stop pin. So, the initial position of the servo does not affect its function. The cable length ensures that the pin inserts are near the 12 oclock. If you adjust the cables correctly, the initial servo position will take care of itself.

[@KartingTaiwan]

Great video, and like in the title, it really completely demystifies the Honda RC valve. I wish you have the first generation AL frame CR250R on your videos, which is what I have. Regardless, I totally enjoyed your video! Please keep it up

[@brian.d.mobley]

HI KT: Im glad you liked it. Like with most of my videos, as time goes by, I think of all the things I would do to improve it now. I may make a updated version of this video soon, but I have so many videos in production these days that its hard to do them all.

[@KartingTaiwan]

@@brian.d.mobley It is very good already, clear solid advice, no BS. Doing videos just take so much resources, I'm glad someone is doing it, good sound advice save us a lot of time and trial and error. Thank you

[@elisteiner5993]

I don’t know if I’m dumb or anything, but I’ve got the factory power valve cables, and when set up on the batwing, there too short to get put into the servo.... am I missing something?

[@brian.d.mobley]

Hey Eli! Dont feel dumb! Sometimes it some silly little mistake. So, first question, are you installing the cables into the servo BEFORE you try to install the ends on the the pulley (batwing)? (Correct answer should be yes, BTW!)

[@elisteiner5993]

@@brian.d.mobley I am, I’ve tried every single way possible for about 2 hours, and I can get one side in and the closest I can get the other is still about a 1/2 inch away from butterfly with out being set in grooves

[@brian.d.mobley]

@@elisteiner5993 can you send me a pic or clip on my Instagram acct? The only other idea that I have is that perhaps you have the wrong cables.

[@elisteiner5993]

@@brian.d.mobley yeah I’ll do that right now

[@llecki]

I need to do this to my 02. I know mine isn’t adjusted right. The bike is to finicky right now... if I measure 10.00 mm on the back side will that give me a starting point to do this adjustment without pulling the pipe or each bike is a little different so I have to do the full procedure

[@brian.d.mobley]

Frankly, if you do the procedure like the manual meant to explain, you’re not far off. It’s easier too, because you don’t have to remove the pipe. The biggest issue with the Service Manual is how poorly they describe the procedure. I really can’t say that starting with a 10mm gap is the right approach though. The gap could vary.

[@jwild79]

Thanks for the great video! Quick question. Will the '04 250 servo motor work with the '04 125?

[@brian.d.mobley]

Hey J! The short answer is; I just don’t know for sure. My instinct says “no” because the CDI is different between the two bikes. Check the part numbers for each. If they are not the same, they are not likely to be compatible. For sure the cables are not interchangeable. Im sorry that I don’t know more that I can share.

[@godsreal129]

Hey buddy can you help me find the Rc valve cable for a 2004 cr125r?

[@brian.d.mobley]

Hey God! Those are unobtainium, sadly. That was a one year experiment for Honda and those cables are not around anywhere. Ive combed the globe! Ebay is probably your best bet.

[@rocker1210]

Really appreciate this video! One question - how does the servo know when to stop powering the valve open? Does it receive a second signal to stop turning the motor but hold in position (such as constant WOT)? Otherwise, how does it not damage the servo gear when it's powering open?

[@brian.d.mobley]

Hey Rocker. THAT is an excellent question and I must sheepishly admit that I am not 100% sure. I believe the servo is signaled to counter rotate in an off throttle state by the CDI, but to really know, id need to connect the servo to a voltmeter while it was running and, frankly, I don’t know a good way to rig that up. Good question though! I wish I could give you a better answer.

[@rocker1210]

@@brian.d.mobley thanks for the reply! I do know blue/green is earth ground (continuity checks to the frame), and they had us do the static motor resistance testing with that and yellow/red, and powered resistance testing with that and light green...so maybe it has to do with those? Who knows...I'm only asking because I'm dealing with some sort of overall powervalve issue, and it could be stripped pinion gear teeth, because everything else is checking fine. Thanks again for this video.

[@brian.d.mobley]

@@rocker1210 Sure! And, Im sorry I could not help more. That one question you posed was the one thing I really could never ascertain! So, big GOLD STAR to you for being the best in class! HA! Regarding the gear teeth, that is a COMMON problem resulting from over tensioning the cables. The gear is plastic, so its not that strong. Some people have fitted a servo gear from a CBR600 (I think) in lieu of just replacing the entire servo.

[@rocker1210]

@@brian.d.mobley I think to really understand this, we'd have to maybe have separate volt meters on each wire (except green/blue) with a tach set up, and watch what happens on a running engine in different parts of the rev range with each throttle condition... preferably on a dyno. Just guessing! But I've heard about the CBR600 servo option, as well as a pinion gear replacement. I'm going to take the servo apart shortly and see what I'm dealing with. I've currently got the engine pulled, cases about to come apart for a new crank, and cylinder out for a replate. Lectron carb on order...should be a great set up once I solve the RC valve problem (and rig the cables correctly!!).

[@brian.d.mobley]

@@rocker1210 I think the technique you describe could work, the problem is, how do you make the wire connections while the bike is running. I wouldn’t want to splice into a wire. I think the best work around would be difficult, but a person could create a jump lead with exposed terminals that was introduced between the plug connection. Almost like adding an extension cord. This jump lead would have OEM plug leads but something in the middle of the lead onto which the leads from the voltmeter could be attached. Its a lot of work, but i think it’s a workable solution.

[@mhengler27]

I can still over rotate it by hand? How do I know the the power valve is gonna line up perfect with the exhaust port?

[@brian.d.mobley]

Like I tell a lot of people, with the RC Valve, you are using a cable and not a linkage to rely on the adjustment. A cable is not going to be as precise. There is no stop pin or other limiter preventing you from over rotating the valve by hand. By using the HRC method, the aim is to create enough slack in the rear cable so that, when the servo has rotated to its open-most position, the cable has retracted to a point where the flap valve lines up with the top of the port. The trade off is that the valve may not start opening until the 3200 RPM mark. However, the benefit is a significantly less pronounced flutter at high RPM. Its not a great system, frankly. Later systems that were entirely mechanical are more predictable. One other note, the difference in the adjustment on the rear cable is only slightly less taut than the Service Manual recommended procedure. Its not the end of the world if you do it like the manual attempts to describe, but the top end performance is better using the HRC method.

[@asalazimi281]

Appreciate your hard work for such a useful video

[@brian.d.mobley]

It's my pleasure. Hope it helped you!

[@bigos.motoowens5813]

Brian, did you use just a straight wire from alligator clip to 12v battery?

[@brian.d.mobley]

Basically, yes. I bought some wires with alligator clips on each end. I only used them because I didn’t have enough hands to just hold the OHM meter leads and battery leads all at the same time. www.amazon.com/dp/B0739YWFQ6/ref=cm_sw_em_r_mt_dp_4qy0Fb20E1SMR?_encoding=UTF8&psc=1

[@scottspecht6690]

Thanks for the video. I've got a 02 CR 250 and was told to set the RC valve at 12mm so Thanks for showing me how to set it up correctly.

[@brian.d.mobley]

Hey Scott. Yeah, 12mm means nothing. I dont know why that value become so popular, but as you now can see, the gap means absolutely nothing. I think people started to just believe the 12mm story because the manual describes the process so poorly and its a simple thing to measure. Im glad I could help. Keep watching and subscribe if you like what you see! THX!

[@brian.d.mobley]

...and I have the same bike! 2002 CR250 (which was used in this video)

[@scottspecht6690]

@@brian.d.mobley That's awasome man. How is the jetting on your bike. I'm thinking about getting an Airstriker carb and V-force reeds to improve throttle response. But all in all I love my bike any tips ?

[@brian.d.mobley]

@@scottspecht6690 Its probably not popular to say, but I have completely stock jets! Im at sea level and it works fine. Maybe I am just used to it, but I think the stock jetting works just fine. If you have throttle response problems, you can change them. If you have the service manual, the jetting recommendations they have have always worked very well for me. I also race a shifter kart and have had to change jets based on temperature and the manual suggestions have always been right on.

[@scottspecht6690]

@@brian.d.mobley Thanks I live in Ocala FL , central Florida sea level and hot and humid most of the year. I never foul plugs but the power delivery seems sluggish compared to my 2000 CR 250 but I love the suspension on my 02. Just thought I'd ask you opinion on the carb. I'll have to see if it improves with the V-force

[@nagoyaka9541]

Hi guy’s, I hope someone can help me, My RC value is stuck open, everything’s clean 🧼 and the butterfly moves freely, Done the servo test, regulator and everything works as should, the problem is, as soon as I start the bike the RC value opens, on idle, the cables and everything’s adjusted as in the video, cables aren’t damaged and i don’t know why, could it be a CDI problem?? One more thing, my bike doesn’t idle very high either, why could the RC value open up as soon as I start the bike? And close wen it switches off? 🤦🏽‍♂️

[@brian.d.mobley]

Does the valve open all the way on idle? And, this may sound crazy, but are you manually rotating the valve to the open-most position before you start the bike? If you do that, the CDI will rotate the butterfly back to closed on starting. As for your last question, its normal for the the CDI to direct the servo to rotate the butterfly to the closed position upon stopping.

[@nagoyaka9541]

@@brian.d.mobley Hi , thanks for your response, The butterfly maxes out all the way open on idle from the close position without any tampering, As I understand, the butterfly should be closed on idle, opening the throttle would then open up the butterfly, I understand on high RPM it should be open, But, as soon as I start up the bike, from the closed position the butterfly opens and then it’s stuck open, I don’t know if I’m making any sense 😅 What could the problem be! Is there any email I could send you a video to better see what’s happening?

[@brian.d.mobley]

@@nagoyaka9541 yes sir. It makes sense what you describe. However, WHY that is happening does not make sense. Please send a video clip to my Instagram

[@fourny55]

The video is amazing! Where do i get replacement parts such as the cables and servo motor? Maybe you have the part numbers? I have an 02 cr250r. Just subscribed too!

[@brian.d.mobley]

Thanks Daniel! Glad you liked it. As for the cables and servo, I tend to like Rocky Mountain ATV for buying OEM parts. They have all the part numbers on their site or you can call them. Thank you so much for subscribing. BTW, I ride the exact same bike that you do! Ride red!

[@fourny55]

@@brian.d.mobley RIDE RED! My bike has a pretty gnarly bog at the top. Super strong low end (insane) but right when it starts to get on the pipe it falls off. The rc lever is super tight (with the cables attached) im assuming the cables are gummed up. Im gonna dig into it later. If the valve is gummed up, can i clean it without removing the cylinder?

[@brian.d.mobley]

@@fourny55 That bog is more than likely, jets. It can also be ignition, fuel flow, air screw.... lots of things! If the RC cables are tight, its highly likely that they are not adjusted correctly. Its is COMMON for those to be improperly adjusted. When they are correctly adjusted, they work just fine even though there are lots of people out there criticizing the valve and its design. Regrettably, you really have to take the cylinder off to service the RC valve. Its not super easy, but if you are patient and careful not to miss a step, you can do it.

[@fourny55]

@@brian.d.mobley awesome, ill take a look into it and keep you posted. It has a keihin pwk carb i believe. I just bought it. Im at sea level on the coast of cali, what jet size you think would be right?

[@brian.d.mobley]

@@fourny55 Im almost positive that on that carb, the recommended settings for sea level are: Air Screw: 1.5 turns from fully seated. Low Speed Jet: 32.5. Clip position: 2nd. Main Jet 390, but check the PWK website to see if thats right! Im not positive on that....

[@Lord_suki]

you have a sub from me i watched all your rebuilds great content gj man

[@brian.d.mobley]

Thank you SO MUCH! You made my day! I really appreciate the kind words and for subscribing. I really enjoy making these videos and its all worth it when someone like you reaches out with supportive comments.

[@Lord_suki]

@@brian.d.mobley i have a 1995 honda crm 125 and untill i watched this video about rc velve adjustment i couldnt make it to work fine. Tnx man

[@brian.d.mobley]

@@Lord_suki There is SO much misinformation out there that its hard to know what to believe. Glad I could help clear this one up!

[@alirahmati2786]

Such a good details you explain

[@brian.d.mobley]

Thanks Ali!! I dont know how I missed your comment, but I like to reply to everyone who comments. I am glad it helped and that you think I explain it well. I try to be clear and organized when I speak, but its not easy sometimes!

[@vicgeier3482]

Fantastic video,I can't stay away,your explaining the work you do is intoxicating

[@brian.d.mobley]

Oh wow! Thanks Vic!!! Thats so nice of you to say. Im really glad it helped. LOTS of bad info out there on the RC Valve, that is for sure!

[@jimmadonna1436]

I have an 04 125 and does the HRC 10mm measurement the same for the 125? This was a great and informative video!

[@brian.d.mobley]

Hi Jim. The technique is the same for your bike. However the 10mm gap is not a specification, its an outcome. I only included that measurement as a comparison to the myth of the 12mm gap. The gap could be 9mm or 11mm or something else after correctly adjusting everything. Thank you for watching!

[@jimmadonna1436]

@@brian.d.mobley I understand now. Thank you for taking the time to answer my question and getting back to me this quickly. I enjoyed the video.

[@brian.d.mobley]

@@jimmadonna1436 My pleasure. Thank you for taking the time to leave a helpful comment that may help others regarding the 10mm value and its interpretation.

[@jimmadonna1436]

@@brian.d.mobley It's a not often that I come across a True GENTLEMAN on this function. I respect the fact that you made an informative video to help the owners of this exhaust port height altering power valve system that the Service manual doesn't go into detail about. Mine says nothing about measures. It was rushed into production. It has an FMF PIPE AND SILENCER and I jetted it according to the FMF chart. I fouled 1 plug since August 2016.

[@brian.d.mobley]

@@jimmadonna1436 Awe shucks! 😊. You’re making blush! Ha! Thanks Jim. I enjoy making videos and it’s rewarding to be engaged in an enterprise whose sole purpose is helping others. Being a content creator is a perfect fit for my abilities and personality. Thanks again for your kind comments and for watching.

[@Mikevlogs95]

hello I have a problem with my cr 125 2004 I have reviewed everything you mention in the video and very good by the way, but my motorcycle has no strength when putting speed as if it were drowning and I have moved it where the servomotor is and it seems to improve at times, I have reviewed the values with the multimeter And it is in range, the resistance varies about 2 to 4 omhs it does not go up to 6.5 but I think I am in range, it only does it at times that it wants to move hard but it always walks like drowned and I already did the carburetion and nothing and how you I comment and I checked cables, continuity, check the valve, the servomotor, and I can't find the problem, disconnect the cable system and that's when it gives a reading to the servomotor and wants to pull hard but it loses reading again and starts very drowned and slow , I don't know where else. something you can recommend me. greetings excellent video

[@brian.d.mobley]

Hi Mike. You didn’t mention changing the reeds. That can cause the exact problem you describe. But fuel delivery problems can be caused by a zillion things- air leaks, jetting, needle height, air screw adjustment, float height, crank seals.... It’s a huge list. It’s very difficult to help someone with these sorts of problems if I don’t have the bike in front of me.

[@Mikevlogs95]

@@brian.d.mobley Is it possible that I can send you a video to see how the servo motor works? please because I can't find what it could be

[@Mikevlogs95]

@@brian.d.mobley I remove the cables to see the servomotor work and it happens that the signal reaches him and the motorcycle works correctly but the servomotor moves strangely back and forth, and it stops working. I move it manually and it returns to its position and the motorcycle works correctly so I don't know where the problem lies if in the servomotor or in the CDI

[@brian.d.mobley]

@@Mikevlogs95 Hi Mike. Sure. You can send me a video, but please understand that I have a full time job and these things can be very time consuming to sort out. Its extremely hard to help with problems like these without having the bike in front of me. I cant dedicate hour after hour of time to diagnose problems such as these, but if its an obvious problem, Ill try to help. [e-mail]

[@GarbageDanks]

Man the 01 was way easier then this!

[@christhalassinos5574]

Hi, if we check all of this that you saw to the video and the problem remains maybe have problem the cdi ????when I start the engine and is idling,the power valve open in the middle and stay in this position regardless of the engine turns....

[@brian.d.mobley]

HI Chris. That is more likely due to carbon buildup on the flap valves. To test, disconnect the cables and try rotating the pulley by hand. It should rotate freely and with very little resistance. Another possible cause is damage to the servo. Many people overtighten the cables and that ends up damaging the internals of the servo - particularly the gear drive inside. CDIs almost never fail, but they do on occasion.

[@christhalassinos5574]

@@brian.d.mobley Thank you very much for the answer!!!!

[@brian.d.mobley]

@@christhalassinos5574 Sure! If you get stuck again, dont hesitate to reach out again. Im starting to get a lot of questions from people on various KZbins I have created but I am still able to keep up with inquiries so far! Please subscribe if you havent! I am trying to hit that elusive 1000 followers threshold!

[@nonitoodjinarjr.4521]

Sir,can I know from where the supply voltage of servo motor coming from. please send to me the complete wiring for my crm 250r.thanks.

[@brian.d.mobley]

Hi Nonito! The voltage is created by the rotation of the crank and the interaction between the spinning crank on which the the flywheel is attached and the stationary stator bolted onto the case. As for the wiring diagram, I dont have that but consulting the service manual is what I would recommend. Thank you for watching!

[@nonitoodjinarjr.4521]

@@brian.d.mobley thank you so much sir..I'm from surigao,philippines.

[@brian.d.mobley]

@@nonitoodjinarjr.4521 Awesome!! There seems to be a lot of motorcycling going on in the Philippines. I get a lot of viewers from that part of the world.

[@addi450]

Very informative video Brian, thanks for taking the time to make this......great work! ps. I always questioned the science behind the 12mm method as there was never any tech to support it.

[@brian.d.mobley]

@deegs12 Honestly, there is nothing out there that I could find to support the 12MM Technique. In practice, it resulted in way too much stress on the rear cable for no reason. The cable will pull just fine with way less tension and you’ll spare the unnecessary strain on the servo motor. Its a popular technique but from my observation was the worst approach. There is no need to crank down so hard on that rear cable. And, there is nothing to support that a 12mm gap creates the magically correct tension. That gap is meaningless. The cable tension and flap opening position are the only considerations for setting the preload on the rear cable.

[@paulcheshire9722]

Can I hook up a 18v drill battery to test servo

[@brian.d.mobley]

Hey Paul. In a word, no. That’s not the correct voltage. If you can, use a car battery or similar.

[@RIDEfor4FUN]

best video, thk a lot mate

[@brian.d.mobley]

Glad to help! Thanks for watching!

[@samuelscanlon1678]

Excellent video, can you do a video on how to replace the servo motor

[@brian.d.mobley]

Hey Sam! I have so many videos in the lineup right now, that I just dont know when I could get to that one!

[@jamestheron08]

Just did the testing on my sons bike the servo turned both ways with 12v add except it failed the ohm test what would the problem be? Great video by the way.

[@tranphucthanh5178]

Thank you, it's very helpful. You are a great guy

[@brian.d.mobley]

Happy to help!

[@jowensedycastillo3531]

Thanks a lot, currently restoring a 02 cr 250 I see we have the same bike 🙋🏻‍♂️

[@brian.d.mobley]

Hey Jowensedy! Thats awesome! I love my '02. Wish we could post pics in the comments. Id love to show it to you. Mine is MINT!

[@jowensedycastillo3531]

@@brian.d.mobley do you have Instagram ? That way we can share a bit

[@brian.d.mobley]

@@jowensedycastillo3531 Yes sir. On my Channel Page there is a link. Or, search Brian D Mobley

[@jowensedycastillo3531]

@@brian.d.mobley will do, thanks

[@zacharystonehocker2146]

I ordered a brand new cylinder core and I don't have the stop pin that the pully hits at the top, will I have to make my own or is there somewhere I can get a stop pin? I've looked for one but cannot find it at all.

[@brian.d.mobley]

You can create one using a drill bit of the same diameter. Cut the shank of the bit to the desired length and “glue” it in place with JB Weld.

[@zacharystonehocker2146]

@@brian.d.mobley Thanks for the idea and awesome video! You really taught me a lot about this whole power valve fiasco!

[@brian.d.mobley]

@@zacharystonehocker2146 Glad to help. And, that power valve is a real nightmare! I’d actually like to do an updated version of this video to clarify a few more things I’ve learned since I made this one.

[@zacharystonehocker2146]

@@brian.d.mobley Hey any new information would be great, keep it up man you are helping out with a lot of our issues haha.

[@brian.d.mobley]

@@zacharystonehocker2146 I’m glad I can help at least some people out there!

[@mnvjim7900]

Hey Brian ! , I have a question about the power valve on my cr250. I’ve noticed some excessive noise from the motor. I’ve read on a lot of fourms, and everyone says that these just make this noise from the power valve. So after I adjusted it your method I noticed that when the valve was closed, it was hitting inside the exhaust port scoring it. I’m figuring this is where the noise is from because it’s mainly from idle. I noticed where you adjust the valve it has a metal stopping pin and tab that comes off the arm. Is this something adjustable or do I need to replace these? Or is it even why my valve is hitting in my exhaust port? I’d appreciate and info you might have on this. Thanks jesse

[@brian.d.mobley]

HI Jesse, Do you have the metal stop pin in your cylinder?

[@mnvjim7900]

@@brian.d.mobley if your talking about the metal stop pin that is behind the “eco valve” cover. Yes the pin is there. But it looks like it scored into the exhaust port. And I think this is the reason for my noise. I’m not sure if it’s the metal pin that is wore out. Or where the pin hits on the arm where both cables are attached. They just don’t seem that worn to be causing a groove that bad. Just not sure what to do

[@mnvjim7900]

“Rc valve”

[@brian.d.mobley]

@@mnvjim7900 Can you email some pics or video? I need to see whats going on. [e-mail]

[@mnvjim7900]

@@brian.d.mobley kzbin.info/www/bejne/mpjWlaNprKyVZ6c. Here is a video I recorded. And I also emailed you photos

[@TheXxgianluigixx]

subscribed to your channel 💯

[@brian.d.mobley]

Thanks so much Gianluigi!

[@antonioauditt]

Complimenti , un saluto dall Italia !

[@brian.d.mobley]

Grazie! Lunga vita all'Italia e lunga vita alla Ferrari. Viva tiffosi!

[@nickmiller7373]

Hey thank you, finally this makes sense. However, on my 04 that i just totally rebuilt (carbon free) my valve does not over rotate? I don't know why?

[@brian.d.mobley]

Is it an 04 CR125?

[@nickmiller7373]

@@brian.d.mobley No it's a 250

[@brian.d.mobley]

@@nickmiller7373 You stumped me. I honestly don’t know why then. Mine is a 2002 and it very easily “over-rotates” (I kind of made that term up as I didn’t really know how else to describe it). The cylinder head is the same from 2002-2004, so I am not sure why yours is different.

[@nickmiller7373]

​@@brian.d.mobley Hmm I can't find a source about it right now but I thought I read somewhere they redesigned it even before 05. Double checked everything and am running it. Thanks for the reply and vid.

[@brian.d.mobley]

@@nickmiller7373 My pleasure.! Thanks for watching.

[@dejalmyers9419]

Where can I get a power valve for my CR250 ?

[@brian.d.mobley]

Hey Dejal. Try Rocky Mountain ATV.

[@dejalmyers9419]

@@brian.d.mobley am not finding any

[@dejalmyers9419]

@@brian.d.mobley can u plzz help me out ?

[@brian.d.mobley]

@@dejalmyers9419 I really don’t have any special sources other than normal retailers like RMATV. Try Partzilla or Motosport. I’m not really in the parts business

[@kaleb71948]

Does anyone know where I can find the electronic power valves for the 2004 cr125? My engine does not have the power valves in it for some reason

[@brian.d.mobley]

I’m sorry to let you know that there is almost zero chance of getting those new anywhere. You may be able to find something on eBay. The cables are not available but I do have two brand new OEM rear cables.

[@kaleb71948]

Hey Brian, If the cable you have is one of the ones that connects the power valve flapper under the RC cover to the server motor than yes!

[@brian.d.mobley]

@@kaleb71948 HI!! Yes. I have a brand new OEM REAR cable (the one without the spring) that fits a 2004 CR125. Honda PN: 14330-KSR-A00.

[@kaleb71948]

Awesome! How much would you charge for it?

[@brian.d.mobley]

@@kaleb71948 I paid $85 for it! Ill sell it for $115 plus shipping. Im in Texas.

[@alirahmati2786]

You did good on this

[@brian.d.mobley]

Thanks Ali!! Im so glad it helped you!!

[@egger2500]

THX THX THX

[@brian.d.mobley]

Sure @egger2500! Glad you found it useful!

[@egger2500]

@@brian.d.mobley I was close with my 2007 but the magic is the real zero Position. Thanks again. Plus it's a very good done video.

[@brian.d.mobley]

@@egger2500 Thank you so much! I worked on this one for a few months!

[@egger2500]

@@brian.d.mobley I can imagine - I just cut parts together - so it's way easier + no talking, hehe

[@shorelinefilms9661]

So your method will fix the flutter?

[@brian.d.mobley]

Hey! Like I tell a lot of people, it’s a cable, not a linkage. So, it can still flutter. But, most of the flutter is due to turbulence behind the port when the flap valve is not in the same plane as the top of the port.

[@shorelinefilms9661]

@@brian.d.mobley dope, my bike doesn’t flutter anymore. I did the method but without sticking a piece of wood in the valve

[@brian.d.mobley]

@@shorelinefilms9661 Im stoked to read that! And the wooden stick thing I used was just one way of aligning the flap valve with the top of the port. There are probably a dozen ways that could be done. But, mostly, I’m happy to read that you had success with the adjustment.

[@shorelinefilms9661]

yeah this video helped big time. thanks for the effort you put into it. definitely can't find one anywhere else!

[@brian.d.mobley]

@@shorelinefilms9661 Thanks so much. Funny enough, Im considering doing an updated version of this video to clarify a few things that have been brought up by viewers. So, watch for an updated version to come out in a couple of months

[@AviatorAriana]

Thank you for your great video

[@brian.d.mobley]

So nice of you

[@jeanpoulbritten3313]

¡ amen !

[@brian.d.mobley]

Thanks! Where do you live?

[@jeanpoulbritten3313]

@@brian.d.mobley from talca CHILE thanks for the info I habe honda CR 250 year 2005"

[@brian.d.mobley]

@@jeanpoulbritten3313 Supuse que estabas en algún lugar de Latinoamérica por el "¡!" símbolos ¡Gracias por ver!

[@asalazimi281]

😃😃😃👍cool introduction

[@brian.d.mobley]

Thanks 😁

[@alirahmati2786]

Your video helped me to do mine

[@brian.d.mobley]

Great Ali!!! Thanks and glad it helped.

[@alirahmati2786]

Hey Brian Keep it up bro

[@brian.d.mobley]

Will do!

[@asalazimi281]

Amazing job

[@brian.d.mobley]

Thank you! Cheers!

[@jimes256]

But the servo will still over open valve surely as it goes to the stop??

[@brian.d.mobley]

Hi Jamie. No sir. The rear adjuster will have more slack in it than it would if it were adjusted using the service manual or 12mm techniques. This slack is what limits the degree of rotation. Thank you for watching too!

[@jimes256]

Brian Mobley I understand what your saying( mine doesn’t really have any slack even with outer nut backed right up to 8mm cable end) but surely no slack and then a bit tighter on 12mm method the servo still rotates the same amount? I guess there’s a track on cb to tell it when to stop. Might put 12v on it to see where stops 🤷‍♂️

[@brian.d.mobley]

@@jimes256 Its a cable and not a linkage, so its always going to be a little imprecise. And, the servo is mounted to the frame and not the motor which also could affect cable tension - even if only slightly. The overall design is not really that great, IMO. However, you should be able to dial out some most of the unwanted slack using the front adjuster. And, the difference between the adjustment for the rear adjuster using the HRC method is only SLIGHTLY less taut than the Service Manual technique. The main issue with the manual is that the procedure is just not explained very well.

[@jimes256]

Brian Mobley yeah not the best design eh?! Thanks for the explanation and the video! Good work 👍

[@brian.d.mobley]

@@jimes256 My pleasure! Thank you for watching!