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-   -   Connecting flywheel to engine question? (https://www.rctech.net/forum/nitro-off-road/428532-connecting-flywheel-engine-question.html)

fixitfreddy 08-24-2010 12:40 PM

Connecting flywheel to engine question?
 
I had a friend replace my bearings front and rear on my RB C6 engine, and he also pinched it. Now, when I try to attach the flywheel, it locks up the motor when i tighten down the flywheel nut. :( Once the flywheel is tight (or even slightly tight) then the rotation of the crankshaft seems like it is binding, and I can barely turn the motor over.

Any ideas what could be the problem?

I've never had this happen on any other motor, so I am confused and concerned - I love that motor!

Jaz240 08-24-2010 12:43 PM

your engine has been piched..you should not be able to turn it over by hand anymore. You need to preheat it to 200 degrees or so and then break it in again

merdith6 08-24-2010 01:11 PM

Hmm
 

Originally Posted by fixitfreddy (Post 7849334)
I had a friend replace my bearings front and rear on my RB C6 engine, and he also pinched it. Now, when I try to attach the flywheel, it locks up the motor when i tighten down the flywheel nut. :( Once the flywheel is tight (or even slightly tight) then the rotation of the crankshaft seems like it is binding, and I can barely turn the motor over.

Any ideas what could be the problem?

I've never had this happen on any other motor, so I am confused and concerned - I love that motor!

I replaced my bearings and it seemed a bit tight after the clutch nut was installed too. Most everyone I asked that knows this stuff, said the bearings were not aligned properly when installed. They said I need a bearing alignment tool, like 90 bucks, great, and when installing the rear bearing you quench it with water to lock in the bearing otherwise it can move when installing the crank, causing it to bind a bit, and in my case the rear bearing went out.....

fixitfreddy 08-25-2010 05:20 AM

I should have mentioned that when I got it back, I ran it a couple tanks a bit rich. Then I brought it home and am now noticing the binding. When I put on the flywheel the first time, I didn't pay attention to the binding, or noitice if it was there - just connected the flywheel and ran it.



Originally Posted by Jaz240 (Post 7849349)
your engine has been piched..you should not be able to turn it over by hand anymore. You need to preheat it to 200 degrees or so and then break it in again


I can't turn it over by hand, but I can turn it back and forth a bit between strokes - my other motors feel smooth, this one feels like the bearing is not as slippery as other motors. When I tighten the clutch nut, it feels like it is binding when I turn it back and forth, and if I tighten it down properly, I can't move the shaft barely at all by hand.

fixitfreddy 08-25-2010 05:21 AM


Originally Posted by merdith6 (Post 7849466)
I replaced my bearings and it seemed a bit tight after the clutch nut was installed too. Most everyone I asked that knows this stuff, said the bearings were not aligned properly when installed. They said I need a bearing alignment tool, like 90 bucks, great, and when installing the rear bearing you quench it with water to lock in the bearing otherwise it can move when installing the crank, causing it to bind a bit, and in my case the rear bearing went out.....

I think you are on to something. I don't want to ask my friend to do anything else with this engine. Who should I send it to so that I can get this fixed for not too much $$$ ?

got_nitro 08-25-2010 05:42 AM


Originally Posted by fixitfreddy (Post 7849334)
I had a friend replace my bearings front and rear on my RB C6 engine, and he also pinched it. Now, when I try to attach the flywheel, it locks up the motor when i tighten down the flywheel nut. :( Once the flywheel is tight (or even slightly tight) then the rotation of the crankshaft seems like it is binding, and I can barely turn the motor over.

Any ideas what could be the problem?

I've never had this happen on any other motor, so I am confused and concerned - I love that motor!

How sure are you that the collet or flywheel is not bad? A bad or worn out flywheel could be doing the same thing. I would check that out first. It's not too often you can get a crank lined up inbetween 2 bearings (in a no tolerence block), have it spin freely and then once your flywheel is locked down it bindes. Sounds like a bad collet or flywheel to me.:nod:

token 08-25-2010 05:42 AM


Originally Posted by merdith6 (Post 7849466)
I replaced my bearings and it seemed a bit tight after the clutch nut was installed too. Most everyone I asked that knows this stuff, said the bearings were not aligned properly when installed. They said I need a bearing alignment tool, like 90 bucks, great, and when installing the rear bearing you quench it with water to lock in the bearing otherwise it can move when installing the crank, causing it to bind a bit, and in my case the rear bearing went out.....

:nod: happened to me - our modder said the same thing, he took out his tool and wahlaa - bearing was was not straight.

fixitfreddy 08-25-2010 05:52 AM


Originally Posted by got_nitro (Post 7852791)
How sure are you that the collet or flywheel is not bad? A bad or worn out flywheel could be doing the same thing. I would check that out first. It's not too often you can get a crank lined up inbetween 2 bearings (in a no tolerence block), have it spin freely and then once your flywheel is locked down it bindes. Sounds like a bad collet or flywheel to me.:nod:

I swapped out the collet for a new one, and tried a couple flywheels - still the same issue. I even tried to shim the flywheel away from the motor to see if the flywheels could now be mysteriously rubbing and still have the issue.



I think the crooked bearing may be the culprit - Who could fix this, and how much would it cost?

The bearings are brand new ceramics, do you think I'll need to replace the rear one again since its been run crooked for a couple tanks?

got_nitro 08-25-2010 05:57 AM


Originally Posted by fixitfreddy (Post 7852823)
I swapped out the collet for a new one, and tried a couple flywheels - still the same issue. I even tried to shim the flywheel away from the motor to see if the flywheels could now be mysteriously rubbing and still have the issue.



I think the crooked bearing may be the culprit - Who could fix this, and how much would it cost?

The bearings are brand new ceramics, do you think I'll need to replace the rear one again since its been run crooked for a couple tanks?


I never had that happen to me but if it was mine for sure I would replace them both.

Edit: Didnt know you tried other flywheels and collets..;)

bacchus 08-25-2010 07:29 AM

Try reseating the bearings. That will also give you a chance to check the bearings since you ran a few tanks already. Check youtube for a boca video on how to replace engine bearings.

fixitfreddy 08-25-2010 07:59 AM


Originally Posted by bacchus (Post 7853170)
Try reseating the bearings. That will also give you a chance to check the bearings since you ran a few tanks already. Check youtube for a boca video on how to replace engine bearings.


Thanks - thats what I think I need to do. I was concerned about not having the proper tools, and not having done it before, I'd hate to screw up this engine while trying to learn to be a good mechanic :smile:

I can't watch that video right now, but I will later. I was under the impression that I needed special tools - bearing puller/pusher - heck, I'm talking out my @ss, but I just don't want to expirament on my own, which is why i gave it to a friend to begin with.

I've read Houston engine service is good - seems to give good advice - do you think I need to send this off, or can I handle it without destroying my engine?

Jaz240 08-25-2010 08:02 AM

There is also the possibility of a defective front bearing. I had a bearing on a brand new engine that was just bad. What happened was when you put pressure on the inner race from tightening down the collet with the nut it would bind up the balls. The thing that drove me nuts was that it would only be felt when the clutch nut was tight. I switched out the bearing and everything was fine.


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