XR 250 valve timing check

[@danb.3397]

FINALLY someone who actually showed the timing marks on the cam ! Very little info on the web for these bikes.

[@Velvethamma]

Dan Bonacum Glad it helped

[@edgardoperezjr9455]

Turning the cam lobes downward is the problem. Turn them so the lobes are up and you will see it aligns the timing marks perfectly. Don't worry about the firing order no hitting because the lobes are up. It will not cause any misfiring problems. I learned this after trying to adjust my cam timing many many times.

[@ferrononferro3941]

Why is this the problem? The timing mark was allready perfect?

[@Toad_Moto]

This video helped with my 79 XL500s. Thanks, man!

[@builtrodewreckedit]

Well if the crank stopped when the cam shit itself. quickly jammed up the engine i think looking into the keyway shearing would be a good idea. Ive seen keys half sheer before... That would change the timing if that magneto even slightly shifts on the keyway... The plot thickens but i think your on the right track

[@mikhailanatoliy9990]

It's funny how you say ''hold that sucker at TDC'' because ''sucker'' is the actual Dutch word for ''piston'' :)

[@parkour1200]

NL fuck yeah

[@D21Offroad]

Holy so precise. Its at TDC you're good to go.

[@Velvethamma]

matt ribeiro yes it was...

[@woodzymike]

Timing looks good.. great video BTW. Just doing mine now and wanted to double check it was correct

[@Velvethamma]

It was.... Ended up being a fuel problem all along even after extensive cleaning on the carb. Live and learn I guess :)

[@WaveAction777]

I hope that one tooth difference makes it right. Assuming all components swapped were all good. Hard to say. Hopefully you have good grounding. You have to wait and give it a try once again with what you just did. Hope she works.

[@Velvethamma]

I find it hard to believe that one of those components was bad but I've had bad luck before..... Wouldn't be the first time, lol

[@robertorochamartinsrocha7041]

Hi... I have up the needle on carb... and my cam it's not alingne worst then yours... mine it's running but if you have a solution it will be great... (think that's a theet down, because i can align it). Thanks

[@bad205]

My air cut off valve in the carb was really dirty on my 86 xr250 causing it not to run properly. I cleaned carb three times before ever seeing the place where the air cut of valve is located. I read you have it going now, good deal. Hope this helps if it happens again.

[@Velvethamma]

That was one of the things I eventually checked out and cleaned up. I can see how easily it could be overlooked

[@tylerwing7820]

1985 xr350r. im at a loss i swear its set perfect timing and it seems like my exhaust valve is hitting the piston???? any ideas?

[@builtrodewreckedit]

That sucks... doing the same thing... I think next step should be inspect the bottom end the pickup coil could it be loose or have a broken wire? Is it adjusted correctly as for gap between the trigger? It may be wise while your in there to pull the magneto check for a broken keyway key if that keyway is loose, sloppy or sheared a bit it could probably cause big timing problems

[@Velvethamma]

I had the pickup coil off and replaced it with another spare. Doesn't seem to have any adjustment (no slot in mounting bracket). I've been curious about the flywheel/magneto. I know with points, a sheared or partially sheared key will make them miss . With this one being a CDI unit, could a partially bad key or sloppy key be the culprit. Pickup coil is on opposite side off the crank sprocket for cam so I wouldn't think it would be an issue. But if there is something I'm missing.... I'm all ears. Don't have a flywheel puller but I do have a spare flywheel. Could a partially bad magnet be causing the high rev cut out? This bike ran tops till it spit the cam chain and broke the cam. I wonder if when it lodged the cam chain in the case that it could have abruptly stopped the flywheel and sheared the key or caused a magnet to shift/fail?

[@happymarthy2855]

Cool, I just tore mine apart but got stack on slack adjuster. The timing chain looks like is gona dance and shout like hell. Any help???

[@w056007568]

This looks good to me but like you I'm no bike mechanic! By-the-way most of us are one eye dominant so most people are right eye dominant so they sight a rifle with their right eye. The way for you to check is take a comfortable stance and hold your thumb out at arm's length with both eyes open lining your thumb with some object 20-40ft away. Keep your arm and thumb steady and close one eye at a time. The eye that sees the object in line with the object is your dominant eye, when looking through the other eye the object has moved!

[@Velvethamma]

I agree with the eye dominance theory for sure.

[@inkZzClan]

My mechanic said my atv is not timed right but it runs fine and he said it's a huge job

[@denrayr]

Did you get it working yet? One of your comments stated that you put a timing light on the spark plug lead and verified that you are indeed losing spark. I don't think the magneto shifting in the key way would cause you to lose spark like that. It would alter the timing of the spark. If the key had completely sheared, the timing would be so far off, the bike wouldn't run at all. I think you should put a test light across the terminals of the coil. See if you are getting a pulse when the bike cuts out.

[@Velvethamma]

Thats a thought. It's strange because I've tested three other coils and another cdi box on the bike and it's doing the same thing. I can't believe that I have that many bad spare parts. What I should do is grab another bike (my buddies all have one) and start putting my electrical parts on it one by one till it fails. That might get me somewhere.

[@denrayr]

I found a wiring diagram. www.4strokes.com/tech/honda/images/84_XR200R_XR250R_Wiring_Diagram.gif I don't know if it is exactly the same as your bike but it should be similar. It looks like there is a part called a pulse generator that sends the CDI a timing signal. The pulse generator is located behind the RH cover, so it is not packaged with the stator. I dont know what type of signal the pulse generator generates, but I would put a multimeter across both wires and measure both ac and dc volts. See what type of voltage you have while the bike is running and see if it changes when the bike cuts off. Looking at the wiring diagram, the cdi gets power from the stator. You could easily test the power here the same way. Make sure the signal is the same when running as when it cuts off. It looks like the pulse generator is no longer available, so I hope that isn't your problem...

[@Velvethamma]

It's sure worth another look. I have changed the pulse generator as well. Both units tested the same with the multimeter. I have a pdf Honda service manual for the bike and performed the tests they suggested. None of their numbers were for while it's running. But since that's when it happens, it's worth a try to see if something is losing signal while running. Thanks for the help!

[@kikenone2261]

How do you do to unlock the chain tensioner and put the pin on it?

[@ChrisC1946]

Idk. I’m lost right now too. No matter how hard I try I can’t get the marks perfect. I hop one tooth and it’s too low on the left, and go back a tooth and it’s too low on the right. It’s just slightly off and I don’t know why.

[@Pawnshoplife]

I’m in the same boat. Mine is either a half tooth off forwards or backwards.

[@ChrisC1946]

@@Pawnshoplife need a timing chain: it’s stretched. I found out the hard way lmao. Hope that helps you.

[@Pawnshoplife]

@@ChrisC1946 that’s what I was thinking. Bike has sat for 14 years because of this same thing. Gonna order a new chain and tensioner and hope for the best! I appreciate it

[@jonnya6107]

Pro tip : Turn the can sprocket around so the lines on it face the same side as the flywheel timing mark (how it should be from factory) so you dont have to keep walking around to check them.

[@MarkSpencerAZ]

Wrong!

[@TRX450RVlogger]

Absolutely NOT. Those lines are meant to line up with the top of the sealing surface of the Cam/Valve Cover... If it's backwards what are you gonna line it up with?

[@xl250mon5]

@@TRX450RVlogger jonny A is correct,the timing marks should be facing the spark plug side and align with the cam bearing housing top face .

[@xl250mon5]

@@MarkSpencerAZ you are Wrong, jonny A is correct,the timing marks should be facing the sparkplug side and align with the cam bearing housing top face .

[@MarkSpencerAZ]

@@xl250mon5 the way he is showing it is correct. You cannot even see the marks if you flip the sprocket around.

[@hanskkristiansen1822]

Hi the haynes manual say TDC MARK IS THE PUNCH MARK ON EARLY 250 MODELS

[@Velvethamma]

Hans K Kristiansen On the early ones the cam gear only has punch marks instead of the straight line marks

[@hanskkristiansen1822]

Hi did you put cam gear 1 tooth advance? if you did so then you are 1 tooth closer to the punch mark. on the net i find on that put the punch mark at 12 clock his bike 87 it started. my bike is a 92 and i did use the straigtht line and wood not start be for along time traying.When start it was fine running good but pain to start. now I have take it apart for 2 time and i fine the cylinder bore have a crack in the wall. I have new bore so before I put the engine back together I like to know what to use of punch mark or the straight line?

[@zackbuckles4170]

I have a 1986 XR250R. Picked it up for 400 bucks thinking it would be an easy fix. I have no bike knowledge what so ever but some mechanical knowledge. I ended up replacing cam shaft and timing chain, 1 lobe was trashed on the cam. put it ll back together by a junky ebay shop manual that wasant worth buying and still to this day it will not run. as far as timing goes I set it up the way you did and still no fire and not as much compression as I think it should have, also cheked for spark and fuel as far as I know. What should I do? willing to drag it out of the garage and take some pictures and start working on it again but I don't know were to start or whats wrong. Please help! thanks a lot.

[@Velvethamma]

+Zack Buckles If the timing is off 1 tooth, it will still backfire and possibly run. If it has spark and fuel, then it's possible that the compression is bad. If it wiped out the cam, it's possible that there is valve damage or the valves could have swatted the piston if the cam failed or chain failed. Even a tiny piece of a valve could trash the cylinder enough for low compression. I believe compression should be 170 - 180 when rebuilt and the decompressor not affected. If the decompressor is engaging, it will be like 90 psi to 110. Lots of variables with these bikes and I'm not a bike mechanic..... Just know enough to get by and ask questions of others when I get stumped :)

[@zackbuckles4170]

Velvethamma Piston actually looks perfect when I rebuilt it I put rings in it and new head gasket but you brought something alarming to my attention. the reason why one of the exhaust lobe was flat on the cam is because the guy that owned it before me adjusted the valve way to tight. ill take some pictures later and see what you think. thanks for the help I appreciate it a whole lot. lol

[@Velvethamma]

Zack Buckles The other thing that might cause valve train issues is the rocker arms. The little contact points could be severely worn for whatever reason and not allowing them to stay in adjustment. I had mine drop a cam chain and break the cam. Scarred up the rockers too so I bought a chinese set on ebay and it has worked well

[@zackbuckles4170]

Velvethamma well I noticed that the rocker were a bit ate up but I ignored it because it didn't look to bad were they made contact. how much did you pay for your aftermarket rockers? honestly I only have about 600 bucks in the whole bike and its got a clean title and is a street and trail if I fix the lights on it. even though its an 86 it in good shape other than the engine giving me all this trouble. it has new cam and timing chain and piston rings its not gonna kill me to spend a few more hundred dollars on it since if I get it running ill practically have a new engine lmao!

[@Velvethamma]

I want to say they were less than 100 bucks for all of them. I replaced mine as a set of 4 because I didn't trust playing mix and match with chinese parts on a japanese bike, LOL. It's been 4 or 5 years since I bought the rockers so hopefully they are still reasonable

[@wtbm123]

Looks good to me

[@Velvethamma]

I hope I changed something for the better...

[@crazeyspivey]

You did not say if you made sure that the valves had some gaps (loose) when you had it alligned at the TDC mark in the inspection hole. You might have been off 360 degrees, and should have rotated the crank counterclockwise one more turn (in order for the valves to be loose).

[@Velvethamma]

Valves were loose and at TDC on compression stroke. Just didn't mention it for some reason.

[@crazeyspivey]

10-4. But an easy mistake for some to make. Getty Up, Hi Ho Silver, Away.

[@dennygreene7693]

why would the valves be loose or gaped

[@Velvethamma]

Denny Greene Because when the piston is at TDC on the compression stroke all valves are closed. That means there will be a .005-.007 gap between the valve and the lifter. If there wasn't a gap then when the engine gets hot, the parts would expand and the rocker arms would float the valves and not let them close.

[@scooterevolution44]

hey i need help on timing my 86 xr250r, i just cant get it, i just put 3 brand new valves and i think i bent them thing is, i can have the flywheel on the T mark, and have my sprocket just perfect like yours, but if i rotate the engine 360 degrees to the T mark again, the lobes are up meaning the valves are open and making no sense since the vlaves cant be open when the piston is up

[@builtrodewreckedit]

Ding Ding Ding I bet you found your problem! When a motor revs up it needs to advance the timing These bikes do that with the cdi Id bet it was out of time and when the cdi box advanced the spark it was already in the advanced position. If that makes any sense? Id bet had it been one tooth off in the other direction it would not have started at all. Hopefully it stayed put while you put it back together. Once you get the timing chain set just like you showed its a good idea to tighten up the adjuster so it all stays put. I hope you get her going with this.... now you may need to lean everything back out eventually and get it back to where the jetting was... good job

[@Velvethamma]

I hope so. I will probably give the cam tensioner a couple of taps to make sure it is in the fully tightened position. I know I didn't do that when I originally did the job. Maybe it skipped a tooth from when I first did it.

[@builtrodewreckedit]

Velvethamma I broke open an old honda manual and tried to remember the timing on a few bikes i had worked on (xl 600s) I realize my last comment was all full of shit.... The pickup coil is down reading the crank.. The spark timing wont change.. That one tooth off is all about valve timing. That sorta makes sense that the fuel mix would seem off. The valves are opening and closing at a slightly different time in the stroke. Maybe not exausting as much and not intaking a correct amount? Im still believing you have found the problem and its going to run great when you get her back together.... Stay positive! P.S. I enjoy thinking about this shit much more these days than i enjoy doing it..... Don't give up youll figure it out

[@Velvethamma]

builtrodewreckedit It's been a hell of a stumper for sure. Gonna get it assembled this morning and we'll see what happens

[@Velvethamma]

builtrodewreckedit Put it back together this morning and still the same old thing...

[@SILVERHORSE347]

Looks good, You got stumble fuxt.

[@Velvethamma]

I don't know if she's fixed or not. I let the slack adjuster go on the cam chain and put the valve cover on with just the center bolt to make sure nothing moves overnight... I'll reassemble tomorrow and give er a test. I have a sneaky suspicion this wasn't the issue. I moved the cam clockwise a tooth but it felt like it slipped back one when I was putting the bolts in it. So I might be back to where I started. But as far as I can tell.. the timing marks are in the right spot

[@Oldrides53]

I've got the some bike an your timing is right on the money. Check your magneto keyway if it's all good Im at a lose

[@Velvethamma]

It has been solved. Was a bad carburetor. I had rebuilt the carb and cleaned it as perfect as I could and something was still bogging it down. Put on another old carb and it runs like a champ!

[@scooterevolution44]

Ok im going to need your help if you want. So when i bought the bike it had 3 bent valves. So I bought 3 brand new valves and a new timing chain thinking that the chain had skipped a tooth. So I put it back together and it fired up once like 3 weeks ago. This afternoon i kicked over 2 hours and nothing. I did a compression check and I was very dissapointed to see 50 psi. I took the valve cover off to check my timing. It is still spot on but i must have bent my brand new valves since it has no compression even without the valve cover meaning all valves closed. So, I need someone to explain to me in details how to do the timing on this bike, what i did to time it, is find tdc, using the T mark on the flywheel, and then making sure that my lobes were down and that my top timing sprocket was aligned with the head (the 2 lines). The other thing is, I can have the motor on TDC and the valves closed (lobes down), then rotate the engine 360 degrees and have the vlaves open (lobes up) with the piston also being up since I am on TDC... which makes no sense since the valves can not be open when the piston is up...... anyways thanks if you read all the way here, if you cant help me just let me know ill set the bike on fire... lol anyways thanks.

[@crazeyspivey]

Did you go on ebay and buy the shop manual for the xr250r? Thats the first thing I did with mine, as it is packed with all the specs and info you need on the valves, etc. Im not quite sure what the problem is on your XR250, but maybe this guy will chime in and give some good advice. Could it be that you have the timing chain off by a couple teeth? Also, you sure you have the correct replacement valves? Hold off on the big bon fire for awhile.

[@TheBlabla1996]

You didnt forget the tensioner for the camchain? none or low tension causes the chain to fly over a few teeth. Also when installing new valve you need to grind them in with a paste (ligthly), or youre valve seat is crap and needs to be recut(you can check this with a marker on the valve seat, then rub valve agaisnt it). Last thing i could think of is that you might have installed your camshaft the wrong way in?

[@crazeyspivey]

Mitchell HürenKamp Mitchell....Question for you: I am rebuilding a XR100R and I notice that the cam chain tensioner has a stress crack at its lower part/base portion. You think that stress crack would reduce the tension on the chain, and I should bite the bullet and replace it while doing the rebuild?

[@TheBlabla1996]

Depending on how you drive id say replace it, if it fails the engine is probably done. Cant you weld it?

[@crazeyspivey]

Mitchell HürenKamp Well, the chain tensioner is a black carbon/plastic material.....so you cant weld, unless you are referring to "JB Weld". The tensioner will probably hold up for many more years, but it could also fail and maybe alow the timing chain to fall off, making for a bad day.

[@chapeledrag9141]

Can someone tell me the cam timing. I couldn’t read it in the vid

[@snocrushr]

Looks to me like it's absolutely correct.

[@Velvethamma]

I remembered what you said about parallax and the difference between what 2 different people see as "aligned" when it came to checking the "T" mark on the flywheel. Closed each eye and checked it. Crazy but I'm not sure it was off at all. We'll see tomorrow when I reassemble it and try and fire it up. When it doesn't run right I'm gonna ...... well I'll be fed up for sure. I like a good challenge but man did I get into a hornet's nest on this one.

[@mossman381]

Have you checked to see that the air filter is not plugged? Otherwise I don't know what to say.

[@Velvethamma]

Not plugged. Checked it already. Gonna check some other things tomorrow before it snows again..... sigh :(

[@mossman381]

I chased a cutting out problem on one of my Polaris Rangers for a long time and it turned out to be the switch.

[@Velvethamma]

I've seen that happen too. Left switch disconnected and does the same thing.... I'm still working on it

[@mossman381]

I wish you luck trying to find the problem.

[@Velvethamma]

Thanks buddy

[@CountrySideClub]

Great videos thanks for sharing Shawn..CJ

[@Velvethamma]

Thanks

[@Yaheuben66]

Never got that deep into my Kawasaki road bike... 'course, that was a long time ago...

[@Velvethamma]

Not many people have the need to. This one is just being a little bitch and hiding the culprit of the problem...

[@derickpelletier5763]

aren't there 2 crank marks on those xr250r's? I'd use a paint marker and make sure there isn't 2.

[@Velvethamma]

Derick Pelletier one is "T" for tdc and one is "F" for fire. Valves are set on the "T" mark.

[@junkerjason7637]

Looks right on to me

[@Velvethamma]

I hope so......

[@SBCK5]

I think it is either a bad ground on CDI box and or bad coil or CDI.

[@Velvethamma]

Thanks for the input! I don't know if I mentioned it but yesterday I spent all day changing out electrical components one by one (including harness) and had no success. Same issues. I would like to think it was electrical but I find it hard to believe that after testing every component and changing them one by one, that it could be. Unless I swapped a bad part for another bad part. I put 2 different cdi boxes in this bike - both worked in other bikes, 3 different coils which worked in other bikes.... etc, etc. It is super frustrating to think that I overlooked anything electrical. Even disconnected kill button for all tests and no success

[@SBCK5]

Make sure the engine it self is well grounded? It sure sounds like a electrical problem to me!?

[@Velvethamma]

Blair Cook I'll make sure the engine mounts are well grounded. That bike only has one chassis ground under the seat and I've already cleaned it and tightened it.

[@BraapEffex]

How do you release the cam tensioner? Can't find any information.

[@Velvethamma]

Invariably Driven If memory serves me well you push down on the square shaped wedge of the tensioner and slide it up. A little tricky but not too hard. The valve cover must be removed first of course

[@BraapEffex]

@@Velvethamma thx, I did that. Then I pryed the other side up with a screw driver. But it was hard has a lot of tension on it.

[@scooterevolution44]

hey i need help on timing my 86 xr250r, i just cant get it, i just put 3 brand new valves and i think i bent them thing is, i can have the flywheel on the T mark, and have my sprocket just perfect like yours, but if i rotate the engine 360 degrees to the T mark again, the lobes are up meaning the valves are open and making no sense since the valves cant be open when the piston is up

[@matthewwebb4662]

I need a camshaft for my 1984 honda xr250. Do you have one

[@Velvethamma]

Matthew Webb Regretfully I do not

[@matthewwebb4662]

Ok thanks

[@ArturasSapalas]

So, what was the problem?

[@Velvethamma]

Bad carb. Put another carb on it and it runs great. All diagnosis lead me to believe it was electrical after cleaning the original carb. Low and behold it was a fuel related problem all along

[@dirt-rippers1018]

How do you loosen the timing chain

[@Velvethamma]

dirt-rippers 101 By releasing the tensioner under the side cover. Lots of videos on this on you tube

[@Nick-dw6rj]

hey what year is this bike

[@Nick-dw6rj]

Thanks...this is going to help me a ton!

[@Velvethamma]

+Nick Moffatt Good luck!

[@inkZzClan]

What happens if it's not in time?

[@Velvethamma]

inkZz Clan It will not run smoothly or may be hard to start

[@ramertv6321]

I know this is an old video but I really need help. I have a xr200r the engine looks identical to yours I am trying to get the cam sprocket back on the cam but the chain seems to tight to get in on. Would you mind explaing what you did to get it on?

[@Velvethamma]

You have to release the cam chain tensioner. I don’t think I videoed that part

[@rgracianoap]

Watching!

[@Velvethamma]

Thanks!

[@rutledge803]

my lifters or valves are knocking on my 82 Honda xr250r idk what is wrong worth it does any one know

[@Velvethamma]

+Coy Rutledge Valve train noise is usually from out of adjustment rocker arms. I believe even the older ones use a cam and rocker arm to actuate the valves. They click or tick loudly when they're out of adjustment. If you have a "knock" it most likely is a piston slap or a connecting rod bearing. Or a ton of carbon build up on the piston. Valves don't usually make a "knock"

[@carlosmorales-wf9mu]

Alguien sabe cuanto eslabones tiene la cadenilla de tiempo ayudeme

[@marksponge9852]

Timing looks right to me but then again I know nothing about dirt bikes.

[@SILVERHORSE347]

I am stumbled by it.

[@Velvethamma]

Me too

[@VicGord]

good video thanks for sharing

[@Velvethamma]

You're welcome

[@brycemeek5759]

Hi my name is bryce I have a xr 250 1979 and need a new air filter housing do you know where I can get it? I also would like to know where you got all of your wiring? To get ahold of me you can email me Jamie and Bryce Meek If anyone else knows this please email me.

[@Velvethamma]

+Jamie and Bryce Meek I would give ebay a shot....

[@kevingeary7807]

There should be marks I just did me ne

[@Velvethamma]

There are marks on cam

[@fishhead3355]

Just weld it back together and she'd be right guaranteed.

[@Cheator40]

Need to cross your eyes when setting that TDC LMAO. Got an easy 6 letter fix for ya buddy... Y A M A H A lol.

[@Velvethamma]

I pushed it aside for now... It has me baffled. Cam timing is dead nuts...

[@jontee2724]

He don't got a clue what he's talking about lmao