Car creeeeps forward at idle

[Cupooterluvr]

As said, my car moves forward at idle, but if I try to give it a smaller air gap it stops running. I also have to trim open the throttle to start it. It sounds like I have it set too rich, but I need to know for sure before I make any newbie mistakes.

Also, if I apply the brakes at slow speeds, my car will quit running. I think the problem may be from the fast idle speed. The flywheel may be spinning fast enough to engage the clutch, causing the brakes to catch the engine as well as the wheels. But once again I don't know!:green-grin: Is there maybe a way to make the clutch engage at a higher rpm? Like maybe it has a screw on it or something, kind of like the 2-speed clutch screw.

Any help greatly appreciated!

 

[jon2]

I think you are still having an idle problem. Your engine should not cut out when you apply the breaks. Have you checked the carb? With the engine off, look down the carb without the air filter, and apply the breaks FULL. Your carb should still retain a 1mm opening. If it doesn't your problem is there.

IMO I think you should reset your needles back to factory and then set your carb opening. Then try starting it again and re-tune.

Let us know how it goes..

 

[rocknbil]

He's right on there, this is definately a tuning issue. If you can't get the idle low enough to disengage the clutch, the tuning is seriously out of whack. Keep after it until you do.

This is important for two reasons: if your clutch is engaged at idle, this will cause it to heat up prematurely and burn out both the shoes and the clutch bearings, and two, with the clutch engaged it puts a load on the motor so that it will be even harder to tune. You're trying to set the idle speed under a load that shouldn't be there.

 

[idle]

if it's dying when you brake, then it might be a broken clutch spring. one broken spring will cause a shoe to touch the clutch bell and engage it.

 

[Cupooterluvr]

"I think you are still having an idle problem. Your engine should not cut out when you apply the breaks. Have you checked the carb? With the engine off, look down the carb without the air filter, and apply the breaks FULL. Your carb should still retain a 1mm opening. If it doesn't your problem is there."

It's set at a .7mm air gap, with the brakes on full. That's also where it's running at idle. I figured out a way to ease my problem, by setting the air gap to about .7mm and trimming the throttle to make it a 1mm gap when I let go of the trigger. That way when I brake, the car will slow its idle speed, allowing it to stay running.

"if it's dying when you brake, then it might be a broken clutch spring. one broken spring will cause a shoe to touch the clutch bell and engage it."

It's brand new, so I'm pretty sure that a spring isn't broken. Plus, that would make me able to turn the clutch by spinning the flywheel. Although, thinking about it, when I pull the starter cord, the wheels do spin slowly. Does this indicate the same problem?

I've reset all the needles using guidelines from some site that sells nitro's. The settings are as follows: HSN 3.5 turns from being fully screwed in; LSN 3.25 turns from fully in; Air gap .7mm. The page says that those settings were slightly rich, let me know if those sound good. The only problem might be that these were made for a .12 engine, not my .18. Are needle settings pretty much universal?

 

[olds97_lss]

Although, thinking about it, when I pull the starter cord, the wheels do spin slowly. Does this indicate the same problem?

Yes, that would be the same. Or possibly your clutch bearings are shot and dragging.

What vehicle is this? Some vehicles come without clutch springs. The only one that comes to mind though is the RC10GT.

Needle settings are not universal. They vary from engine to engine. Most will run but with the HSN from 4-5 turns from bottom and the LSN flush with the housing. Typically that's kind of rich.

 

[Cupooterluvr]

"What vehicle is this? Some vehicles come without clutch springs. The only one that comes to mind though is the RC10GT."

It's a 4wd rc buggy, www.exceedrc.com I don't know what kind of engine it is, it says "vx-18" on it with a dot and 3 consecutive 1/4 circles. Is there a company called vertex that makes rc engines? If so, that's probably what mine is. Does anyone know the website?

"Needle settings are not universal. They vary from engine to engine. Most will run but with the HSN from 4-5 turns from bottom and the LSN flush with the housing. Typically that's kind of rich."

That's about where mine is, only the lsn is about 2 turns in and the hsn is 4 turns out from closed.

EDIT:

Did some research and came up with this:
http://www.treasuretrovetoys.com.au/prod8.htm

That's my engine, only mine has a black cooling head. Does anyone know the actual website of this engine's manufacturer?

 

[idle]

It's brand new, so I'm pretty sure that a spring isn't broken. Plus, that would make me able to turn the clutch by spinning the flywheel. Although, thinking about it, when I pull the starter cord, the wheels do spin slowly. Does this indicate the same problem?

it is sounding like it's a clutch related problem, rather than a tuning issue.

seriously, it can't hurt to take out the engine, undo the clutchbell and have a look. it will take you 2 minutes to check and 2 minutes to put back together. much less work than playing with your needles. the other way to look at it is if it *is* a spring/bearing issue and you tune around it, it's going to make your life more difficult in the long run.

I've just had a spring break after 6 tanks of gas. brand new shoes, brand new springs. because I was breaking in my motor, I finished the tank. now the shoe needs replacing too.

and as olds97 says, check the bearings while you've got it open.

the clutches are like glow plugs: disposable. I've had springs last 10 months, and I've had them last an afternoon.

 

[Cupooterluvr]

Yep, it's broken. Or at least it looks like it. When I took the bell off, the little spring shot out onto my lap, getting grease on my jeans. It looks like it could still work, I'll post some pics or a video on youtube.

 

[olds97_lss]

If you have a LHS near you, it may be easier just to take your shoes to the store and compare to parts that they carry. Most 1/10 clutches are pretty similar, so you may not have to wait for shipping and whatnot.

 

[Cupooterluvr]

youtube video:
[ame="http://www.youtube.com/watch?v=VvdwrugdMp8"]YouTube - Clutch spring[/ame]

 

[jon2]

from the looks of your ride it is a 1/10th scale rig. That type of spring is common in Traxxas rides. You may want to bring the spring in and compare it to a traxxas revo clutch spring. it just may line up right.

 

[olds97_lss]

It would be better to see a clear pic of it rather than a fuzzy movie...

You can try and stretch/reform the ends so you can connect them again. But, if a piece has actually broken off, it will be a little shorter and may affect engagement.

I'd try it though. You have nothing to loose.

 

[Cupooterluvr]

It would be better to see a clear pic of it rather than a fuzzy movie...

You can try and stretch/reform the ends so you can connect them again. But, if a piece has actually broken off, it will be a little shorter and may affect engagement.

I'd try it though. You have nothing to loose.

I suppose a shorter spring might make it harder to engage, and since my car has a fast idle anyways, it's no big deal.

 

[olds97_lss]

Yes, but if it's too short, then it won't engage at all. I've broken a few springs like yours before. Normally, the end just broke off. Then I'd take an exacto, split a ring on the end of the spring so I could form it into a hook with needle nose.

 

[Cupooterluvr]

Same thing with me, only I had to stretch it a little to get it to fit. Since there's a new part on the way, a little deformity like that can't hurt right? Or will it affect the engine in some way?

If the spring pops off when I'm running it, is it possible that it could grind x part into y part and make me have to replace both?

 

[Cupooterluvr]

I fixed the clutch, I'm just waiting for my neighbor to get home so I can borrow his thermometer gun. Hopefully the car is set fairly well.

I had to bend the clutch spring to get it to stay, hopefully it'll work if I get it running today.:goodpost: