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Old 08-08-2010, 04:57 AM   #1
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Default RC8 Won't just sit running at idle without moving.

I noticed yesterday that my RC8 won't just sit running at idle. It wants to go. I also noticed that when I apply the breaks that the engine stops. Is this because the applying the breaks stops the large spur gear, which stops the clutch bell from rotating and the shoes are staying engaged? Is something to do with my shoes, springs, shims etc?

Thanks

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Old 08-08-2010, 05:04 AM   #2
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The engine is revving so high that it wants to engage the clutch.

1. Check clutch to make sure that no springs are hanging and that your bearings are good.

2. Check Idle gap to make sure it is set to .5- 1mm and that the slide doesn't close all the way when you hit the brakes. if your idle setting is right. Fatten the bottom end needle to bring the idle down.

As a precaution I would check my entire fuel system.


What engine are you running?
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Old 08-08-2010, 05:13 AM   #3
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The engine is revving so high that it wants to engage the clutch.

1. Check clutch to make sure that no springs are hanging and that your bearings are good.

2. Check Idle gap to make sure it is set to .5- 1mm and that the slide doesn't close all the way when you hit the brakes. if your idle setting is right. Fatten the bottom end needle to bring the idle down.

As a precaution I would check my entire fuel system.


What engine are you running?
This is an OS V-Spec 21.
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Old 08-08-2010, 05:21 AM   #4
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+1 the engine may be idling to high, if the idle is ok i would check for a broken or week clutch springs, check for burs on the clutch shoes(as the clutch wears you get alloy on the edges of the shoes) and lastly the shimming of the clutch bell, as it may be to tight and bearings, good luck with it, but should be easy to sort out.

cheers
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Old 08-08-2010, 05:39 AM   #5
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+1 the engine may be idling to high, if the idle is ok i would check for a broken or week clutch springs, check for burs on the clutch shoes(as the clutch wears you get alloy on the edges of the shoes) and lastly the shimming of the clutch bell, as it may be to tight and bearings, good luck with it, but should be easy to sort out.

cheers
Scott
I just took the bell off and noticed one of the clutch springs was not siting right. Too early for me to fire up the motor and test it to be sure right now. Just so this is correct since I'm still a little new at this. The top of the clutch spring should be resting up against the cam right?

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Old 08-08-2010, 10:05 AM   #6
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on my rc8b one of the post on the flywheel for the clutch shoe worked its way out and was rubbing on the clutchbell causing it to spin at idle.

also if you are not running a throttle return spring might be a good idea and just set your idle right once its up to temp
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Old 08-08-2010, 10:09 AM   #7
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ur idle must be way to hight to be moving and when u hit the brakes its closing the carb causing engine to flame so u need to turn down the idle set the throttle servo end points get the manuel and make sure u set the throttle horn right and check ur clutches.
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Old 08-08-2010, 10:18 AM   #8
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It sounds like you may have found your answer already.

This is definitely a clutch issue. Broken spring, seized bearing or some other component failure. Rebuild the clutch and you'll be back to normal.
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Old 08-08-2010, 11:17 AM   #9
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The pins have been working there way out on several of my flywheels. I heard it has been a problem with a few others that I know. I went back to an older flywheel that the pins are a little worn, so i am waiting to find out if AE has a new run coming or what?
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Old 08-08-2010, 11:40 AM   #10
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Sounds like siezed clutch bell bearings to me. Or check the clutch springs or your shimming on the clutch bell. Think it is the clutch bell bearings though, JMO. Good luck finding it.
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Old 08-08-2010, 11:55 AM   #11
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How do you know when your clutch bearings need to be replaced? At first glance they look fine to me so I'm not sure what to look for to tell if they need to be replaced. They have about a gallon of fuel run on them.

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Old 08-08-2010, 12:14 PM   #12
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If you have almost a gallon of fuel on them they probably need to be changed. I've never had a set last a whole gallon.
Also look and see if when you hit the brakes, it's closing your carb some, compared to when it's just idleing. Or if when you hit the breaks your idle drops some. If it's doing that you endpoints are setup wrong for your throttle. You might need to tighten the spring up some that returns your carb back to it's idle setting whenever you let off the trottle. Mine did the same thing for awhile until someone showed me how to fix it.
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Old 08-08-2010, 12:17 PM   #13
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Without getting into a deep discussion on clutch bell bearings, here is the short answer.

Cheap insurance is replacement on a frequent basis....

Avid, Ready Rollers and Panther (I'm sure there are others) all offer $1 bearings.

These are consumable items and IMO, it is not worth trying to get multiple gallons of run time out of them.
Pushing the envelope could result in a DNF, or worse yet, damage to other parts.
Is saving $2 worth killing a clutchbell, or possibly a crankshaft?

Easy way to check a bearing is to clean it up, (pop seals out-spray with motor spray/brake cleaner, etc), hold by the inner race and spin it.
If it feels gritty, replace it.

Opinions vary on the subject and I'm sure a long discussion will follow.
This method works for me, along with countless others in the hobby, so that's what I recommend.
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Old 08-08-2010, 12:32 PM   #14
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Quote:
Originally Posted by bevofrancis View Post
If you have almost a gallon of fuel on them they probably need to be changed. I've never had a set last a whole gallon.
Also look and see if when you hit the brakes, it's closing your carb some, compared to when it's just idleing. Or if when you hit the breaks your idle drops some. If it's doing that you endpoints are setup wrong for your throttle. You might need to tighten the spring up some that returns your carb back to it's idle setting whenever you let off the trottle. Mine did the same thing for awhile until someone showed me how to fix it.





the tko clutch bearings will, last more than a gallon im on my second gallon and there still just as smooth.

and im running a all alum clutch setup.
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Old 08-08-2010, 12:44 PM   #15
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Quote:
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the tko clutch bearings will, last more than a gallon im on my second gallon and there still just as smooth.

and im running a all alum clutch setup.
x2. I just changed the clutch out of my truggy, still had life in it mind you(23.5) and i was pushing 3 gallons on it, original bearings. they felt perfect, it was like they were brand new, I usually change them when i change my clutch and they felt so good im still using them on the new clutch. tko are bomb, they extended my clutch life and the bearings last for ever.
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