Rw Mods Nitro Engine Tuning

The first volume, covers basic nitro engine settings.
This does not cover everything, let me know if you have something you want me to do a video of.

[@danachecrallah4724]

R.I.P. Mr Rex Welch you will be missed by a lot of folks.Peace and love too the family that lost a great man.I did not know Rex personaley but i feel like i did by watching his reviews and teachings God Bless Dana

[@underdogrcracing1988]

Amen same here I learned so much over my years into RC. I have been thinking about him lately he would always help anyone with info or anything he could. R.I.P may your info live on forever Rex.

[@RcOffroad9513]

The RC community misses you bro! Hope your flying high! RIP man!🙏

[@underdogrcracing1988]

Amen we sure do. He would help anyone in a second

[@bradleymilton9372]

Rip rex

[@bradleymilton9372]

He is up.there woth all.gis cars enjoying it

[@traxxasrc10]

Damn, well This weekend im for sure checking my idle gap! Finally a good demonstration and explanation 🙏🏽

[@donfoss45]

That was a excellent video plenty of information that any Nitro guy needs to know because I run into those problems

[@fpvandgasrc4321]

very helpful man thanks

[@narongrachmareongsit1978]

❤😂🎉😢😮😅😊. ไฟไฟไฟไฟไฟแอดพ์. ?

[@RedlineNitroWerks]

R.I.P KBN

[@keithhayter3178]

you need to teach classes. I will be the first in line

[@TheRwmods]

Thanks, I might do some classes locally.

[@sn47som]

Awesome vid once again! Do a break in vid!! theory, talk and maybe some demo please

[@TheRwmods]

It is a little old and I need to do a new one. kzbin.info/www/bejne/mYLJXnVoitZ2irs

[@sn47som]

@@TheRwmods Ah yes I've seen this a long time ago. Great vid tho! What do you think about the wot method?

[@TheRwmods]

@@sn47som Do not like the wot method.

[@rcsendandblast1579]

Sweeeet we just spoke on the phone. I’m the guy who asked about pinch and stuff Huge thanks for this I needed to see this 🤘😎

[@Clickbaiters]

Excellent video! Very, very few people on KZbin have a clue on how to tune. Video's like these are essential to keeping nitro alive. The last portion of the video where you revisit the lsn and idle gap simultaneously in order to get the idle to lay right down and not carry on is one of the toughest to figure out without having someone show you a proper example. Tuning a short needle carb is much easier than a long needle carb and it's one of those things I need to work on. You clearly know your stuff and it's a breath of fresh air with so many morons on KZbin. A nice low idle is music to the ears.

[@keithbates8482]

Nitro forever 💯💯

[@tommieharrell706]

Was that fx engine modified

[@TheRwmods]

No it is not modified.

[@bradleymilton9372]

Watching this 5 years later knowing he is dead os freaky miss.him so much he would help anyone

[@sebtarta]

Rex, when at the track, end of the straight and you hear the engine pinging after letting go off the throttle, is that lack of fuel on the HSN?

[@evanlewis1321]

Yes lean high speed needle causes that run-on at the end of the straight and sometimes over jumps causing the car to nose up in the air. If you pull into the pit at the end of your run and it idles high for a while then drops off, your low speed needle is set too rich also. Not many people explain tuning like Rex does in this video.. Great info!

[@nycedreamz615]

Thankyou for very useful information.I am new to nitro and i am trying to take in all the knowledge i can get. Right now i am having a problem when i go past half throttle the engine dies... What are the changes i should make to either low or high speed?

[@TheRwmods]

It could be rich or lean and die like that. Most times it is rich, kinda depends on how it sounds.

[@sn47som]

aren't you supposed to pinch the fuel line at the carburetor nipple to test lsn?

[@bradass_drummer]

Mark Juliano yes

[@CraigAndres]

Hi, may i ask what engine, pipe manifold combo that is? Are the FX engines a little more linear than the O.S speed engines? Great video! I learnt a lot 👌

[@TheRwmods]

Fx K501R they quit making the cheaper R version. Aplus 0801 pipe with std. u header. I think the Fx K301 is more linear. It depends on wich Os model.

[@JoseJose-zf8ej]

Question what is the normal temperature whn they hot on this engines im new in this hobby any help will be much appreciated

[@TheRwmods]

A nitro engine should always be above 200 degrees. (95c) and at maximum about 270 degrees (135c)

[@DR-br5gb]

EXCELLENT Vid RW!! I really appreciate the idle gap gold nuggets -Doug

[@TheRwmods]

Thanks!

[@l0ckd0wn360]

why so less views i love this video thanks alot mate

[@ThePIPdesign]

Superb tutorial

[@ZingZingNZ]

better than jq video

[@cmtlights]

your video is awesome! prolly the best tuning video out there! thank you!!!

[@TheRwmods]

Thank you

[@jbrc1322]

Thanks for the relatable tuning info. One question- If the carb has a "mixture control valve" or "midrange" adjustment, is it recommended to tune this after tuning the hsn, and lsn? And do you look at the 1/4-3/4 throttle range for this? Specifically looking at the os 11k-r carb. Thanks!

[@brandonbelstad6450]

Best sense of a tuning video I've seen. Nice job!!

[@TheRwmods]

Thank you!

[@bradleymilton9372]

Missing you man fly high

[@craigjones2015]

Iv sorry misspell

[@trickmustang1994]

RIP brother.

[@royarsey5429]

i am interested on the exhaust pipe...what brand or made by is it? i'm just tired of chrome / polishing or having burn marks..nice tip on tuning /Thanks !

[@TheRwmods]

This one is a 0801 made by Aplus, they made pipes for Alpha and Argus and maybe some others. Not sure if it is available anymore, there are some other pipes made with a hardcoat.

[@royarsey5429]

@@TheRwmods / Thanks for your reply and info..i saw a CRF 2149 hard anodized (Black) i think CRF is also Orion..? i have a new engine to break-in,Do i still need to set the carb.?or leave it as factory setting...opening the carburetor will not mess up the engine ? Just leave the HSN / LSN as-is..Thanks in advance for helping..I'm a newbie on carb.setting/maintenance...

[@TheRwmods]

@@royarsey5429 Crf is Orion basically. I would try to break it in with the factory settings. When you are finished break in then look at the idle gap before race tuning.

[@GSXRTZ]

Thank you!!!

[@MrLilChilly]

Great video. 1 thing you covered that most don't take into account is the difference in short needle and long needle carbs. Most people will not even check into that when buying an engine. Then find themselves chasing their tune. Great job.

[@TheRwmods]

Thank you!

[@l0ckd0wn360]

the FX engines have a short needle anyway so hes pretty much covered it.

[@MrLilChilly]

Kyle Taylor so true, I just like that he was us aware that carbs can come with a short or long needle which the turning procedure the two is similar but different.

[@tonyromano6220]

Chasing my tune! Yes Sir!

[@ronniewilliz153]

Great advice man. Very nice job i got 2 tanks in my new old stock xtm mammouth. Gonna burn some more nitro first thing in the am

[@brandonsheldon4783]

Should my idle gap for the lrp .32 be bigger?

[@underdogrcracing1988]

No should be around same or smaller

[@RandoTark]

Awesome video! I had no idea bout the short vs long LSN difference in carbs! I do have a question regarding my engines behaviour after loading up when sitting idle(which is usually anywhere between 10-20s after a straight). Once engine loads up, if I give it like half throttle for say 1/4 second, the engine seems to not fully clear out ... so when it comes back to idle it actually bogs down below idle and sometimes will die in that bog period. I noticed in your video it happened once(the bog but didnt die) and I think u described it "gurgly" ... is there any way to get this smoothed out?

[@TheRwmods]

If you idle the engine for a long time the crankcase will usually have alot of fuel in it. (even if the lsn is pretty good) That is why you need to be easy on the throttle after it has idled for a bit as to not flood it out. If you don't fully clear it out then it can load up and die, it will take a few revs to clear out the extra fuel.

[@RandoTark]

@@TheRwmods yeah i figured that was the case, its just that i got a .28 rtr recently and compared with the rc10gt .12 ive had for decades, the stall i describe is a new phenomenon i experience on the .28 and never seen on my .12 :-\ so that's why I'm a bit confused :-P anywho yesterday i experimented with a lil leaner lsn and made idle gap a tad smaller ... the idle is a nice low one like your vid now and seems like the gurgling idle stall after sitting while is less of an issue now, yay! i think i still got the bottom pretty rich, so will keep leaning her out, i did some shorter high manuever driving that was a lot of low throttle punching and noticed quite a lot of smoke more i did it, so I'm thinking bottom is still over rich a bit.

[@blaqkyellow]

Do you recommend ceramic for the bell or stock shield bearing?

[@TheRwmods]

Clutch bell? I use Tko spcial clutch bearings, they are $3 but last 5x as long or more.

[@thargor6750]

good video!

[@JMACK-re9di]

Very good video and extremely informative. The audio of the engine was on point as well. thx

[@TheRwmods]

Thank you!

[@nitrogas5719]

On long low speed needle carbs do we tune the low end first and then the high end?

[@TheRwmods]

I first set idle gap then get the idle the right speed with the low speed, then hsn last. The difference with the long lsn is that it can effect mid and top so you might need to say richen the lsn if it cuts out in the mid range. A little more messing around.

[@nitrogas5719]

TheRwmods thank you

[@sn47som]

Hey Rex how are you? Im stuck Ive never really seen this symptom before. Here's my set up: 3/4 of a gallon through a Max Power Extreme engine. Still gets stuck at TDC when engine is hot. I set/balance the carb properly before running and proper idle gap. 9mm carb insert 41032/9886 exhaust Bones Brew 30/8 fuel Nova 6 plug Buku Clutch No matter what I do with the tune it always has this delay, now with tuning I can remedy some of the delay but it never gets smooth take offs no matter what there is always a degree of delay on take off, then the buggy takes off. It acts like a lean low speed but there's a lot of smoke coming out the pipe low to mid acceleration so this has me baffled. I heard a large carb insert can take away low end response. Do you think it could be the insert? the tune? or the header? Thanks for any insight.

[@TheRwmods]

Possibly clutch? In your instance I would rev it up and clear it out. Let it idle for 5 seconds, then pinch the fuel line. If it revs up before 5 seconds the lsn is on the lean side. If it runs up to 10 seconds the lsn is on the rich side. It is hard to tell sometimes if it is lean bogging or rich. The 41032 really makes them snappy off idle. You could also try a #5 plug but may need to add a thin shim.

[@sn47som]

@@TheRwmods are you familiar with setting the buku? and do you mean possibly springs are too loose? too tight? or malfunctioning? What about the fact that its not broke in yet? It doesnt idle to great- takes a while before it idles on its own maybe 12 minutes of warm up

[@TheRwmods]

@@sn47som New engines should idle really good. I have never used a Buku but they have a base setting. Doesn't idle meaning it just idles too low and dies? If it is tuned correct it should idle nice and maybe get a little rich and load up after 10 sec.

[@sn47som]

@@TheRwmods So you're probably saying it's more the tune (as it usually is the case) than the fact that there's a lot of pinch causing an inconsistent idle? Everyone says (of course reputable e guys) that are in agreement that new engines DONT idle well because of pinch and poor fitment- not broken in. So the idle raises and lowers due to it being not a good piston/sleeve fit. This makes sense. My engine is acting like a lean lsn would on idle - keeps raising up then comes back down to constant idle then raises up for a second and comes back down- Now the question is- is it "new engine-itus?" or the tune? I checked the tune first and the lsn is turned in a lot but if I richen the lsn from that point it won't even stay running. It wants to be lean right now on lsn to stay running.

[@TheRwmods]

@@sn47som Nova 6 plugs are kinda hard to break in with. With a colder plug the tuning window is small and it will just die if it is rich. Try a #5.

[@tonyromano6220]

Good video!

[@craigjones2015]

Thanks if been running into that issue it cleans out the idle gets high. Then after 5+ seconds it drops the mid to high end is crazy fast.

[@TheRwmods]

Usually idle gap is wide if you clean it out and the idle is high. Could be a lean hsn also.

[@craigjones2015]

Do I need to keep doing what you said. Clean it out and lesten to the idle and if it's high keep lowering it. Then fatten the bottom end up 1 hour at a time. Then clean it out and lesten to it again. Then see how long it will idle before loading up and die. Then if it does lean the top end 1 hours and keep repeating the process until it will keep a steady idle

[@craigjones2015]

@@TheRwmods ok so when I go down the straight away and let off the throttle the carb closes . The RPMS are high. But if I stop the buggy and let it set normal I can count to almost 10s before the RMS come down. To a low Rpms does that mean I do not have enough fuel coming in and the motor is starving for fuel. I reset the idle gap just now it was I would say 1mm+. I set it to about the thickness of a paperclip or a hair above that.

[@craigjones2015]

I watched your video on your truggy. I like how yours does that's what I'm trying to get. You give it full throttle and as soon as you let off its comes down to a low idle right away with no hesitation.

[@TheRwmods]

@@craigjones2015 You can not even start tuning without setting idle gap first. On the lsn one hour on most engines is a very small adjustment. I normall go 1/4 turn at a time until you get close.

[@terryshrives8322]

You have a double idle! Thats not the way to tune. Your idle gap at .70 is to big. Its not just os engines that run at a .50. Most engines run at .50. Very few engines run well without a double idle at .70. I would bet by the time he got rid of that double idle, the gap was around .50. Do not start with your gap at .70. Always start with a .50. Do you see how long it took him to get rid of that double idle? It’s because he set that gap with a paper clip. Set it at .50, I’m saving you lots of time. He still didn’t have the double idle out all the way and he had to keep closing that idle gap more and more like I said. You can do it in a quarter of the time it took. When your double idle disappears completely and your idle is perfect, it will drop instantly after letting off the the throttle. Thats when your engine is perfectly tuned. Always set the high speed first. See, if you do it the way I said the engine tunes itself. You should be able to sit at idle for 45 seconds to a minute or longer without loading up at all. I have done this a long time. Thats the way a master tuner does it. After your gap is set in the way I told you, you never touch it again. All tuning for the rest of its life will be done through the high and low speed needles after that. Thats how you you do it. Get rid of the double idle completely. Right when that happens, thats where your engine wants to be. From there, its just small adjustments on the high and low.

[@jkrzton89]

Hey Rex .love your content. I recently bought a kyosho inferno gt2 on road car. What is the fastest engine you could recommend to me?? You opinion will be greatly appreciated thanks..

[@underdogrcracing1988]

Sorry to inform you but Rex past away the other year he is missed dearly and would have helped you in a sec

[@doug148877]

Do you think we'll ever see some sort of fuel injected rc nitro motor?

[@TheRwmods]

Maybe in the future, not sure. It would be much more expensive.

[@Dagcor1]

I saw a chainsaw 80cc recently with fi maybe just a little sooner than later?

[@straighttimestirrups]

Nitro engines are a form of fuel injection already. The exhaust pressure pulse which is higher than ambient is injecting the fuel Under pressure into the Venturi.