250r problems continue..

[jrooster]

as some of you may have read in my other posts, I had my 250r engine rebuilt top and bottom at CT racing. I finally got it installed and running but am getting a whirring/whining that increases when given throttle. It sounds like its coming from the clutch side of the engine. This is not my video but it sounds almost identical to this. Not quite as loud but the same noise. CT rebuild my counter balancer and were supposed to replace any bad bearings. What do you guys think?

skip to 20 secs on this vid https://www.youtube.com/watch?v=8b1mOdXaaU0

https://www.youtube.com/watch?v=6jPsK7vAE0c&feature=youtu.be

[Jmoozy27]

That is strange sounding. Sounds like a damn spaceship!!!

[El Camexican]

If you have doubts as to having property assembled the engine you may want to pull the right side cover and make sure the gears between the crank and the clutch are aligned. That's about all I would be concerned with. I don't know if the balancer shaft I hear Honda's have is part of transferring power on these engines, or if there are any spacers or shims behind the clutch hub or crank gear you could have put in wrong. There is also a clutch mod for the Hondas that requires you to grind some material off the clutch gear. but providing you have everything assembled correctly with the right parts I don't hear anything out of the ordinary in that video you posted

Your engine should have what are called straight cut gears on your clutch and the end of your crank shaft. They make noise due to their design. The alternative is helical cut gears that make less noise, but rob you of power and can cause strain on everything else. They are quieter, but they have no place on a performance engine.

So anyway, people routinely mix and match clutch and crank gears when building an engine, i.e. you may have a new gear on your clutch basket, or the gear on your crank gear may be from another engine. When you combine a used gear with a new gear, or two used gears from different engines they need to break in and mate to each other as would two new gears. This is not the best thing, but people do it all the time.

KTM actually sells these gears in sets, if you buy a full KTM clutch basket it comes with a new crank gear, but I've mixed and match them without a problem. Even when they are both new they are loud as heck when the clutch is engaged at idle, but as Glamy seems to be suggesting, the sound of the gears should dissipate when you are riding, or when the clutch is disengaged.

The reason the noise subsides when the clutch is pulled in (disengaged) is that the clutch hub assembly (which is not totally rigid) no longer has to turn the input shaft of the transmission and is free to rock and conform to movements of the more rigid crank assembly. The transmission also adds to the noise factor when its spinning freely.

The noise should also go away, or at least be masked when you are riding and have a load on the clutch and transmission as all the components are "loaded" and stop having the ability to "rattle". Unfortunately the noise won't get much better with time, but you will get used to it.

[atc007]

Video sounds like every R I have ever been around. They do have that whirl to them. CT is a highly respected company, break it in right. Clean, oiled air filter, good oil,don't over rev it and don't bog it the first tank. Check your plug after 3 or 4 minutes of "riding" check it again after picking up the pace. I assume you have been in contact with them over all the issues. If anything goes wrong with this,I think they will gladly stand behind it. I completely understand your hesitations,anyone spending that kind of coin wants to be confident! But I think she'll run great.

[250rRoostmaster]

Have you checked for play in the CB bearing holder? My R has a slight whirling noise like that. Been there from day one and I replaced every single bearing, motor was built by LED performance. I wouldn't worry

[jrooster]

when i get some time im going to check the holder out. I talked to a guy with the same whirrling noise and thats what it ended up being. Something about the bearing spinning in the holder?

[250rRoostmaster]

when i get some time im going to check the holder out. I talked to a guy with the same whirrling noise and thats what it ended up being. Something about the bearing spinning in the holder?

Yea, when the balancer bearing gets worn, it allows the balancer to move around which wears out the bearing holder on the opposite side. You can get a new billet holder from ESR for pretty cheap if that's the case.

[Dirtcrasher]

Yep, The ESR cover and new bolts should be in there now......

[averysdad]

I just picked up an 84 250r it makes a noise in neutral with the clutch out if you pull it in the noise stops kind of a knocking noise is this normal for air cooled 2 strokes?

[Dirtcrasher]

That just mat be a shortage of separating the plates due to a worn clutch pivot from the cable. IDK if those motors had a rod, but they're usually worn down.....

[averysdad]

I will try to post a video later thanks