simonRC

my wheels keep turning at idle. I have done the pinch test and and it dies after 3 seconds just like it should but i just can't get the wheels to stop spinning even when the engine is warm. the gap in the carb is set to about 1-1.5mm but if I put the trim down to bottom so only the 1mm gap is left, it will die. if I richen it up at the bottom, it will just cause the engine to stall rather than stop the wheel spinning.

I really dont think this is a needle setting issue. Can anyone suggest what else this maybe?

Thanks in advance

Fuel Crazy

My Feedback: (1)

is it moving when you put it on the ground?Or only when its off the ground?

Likely the clutch is staying engaged... pull the clutchbell off and see if the spring broke.

simonRC

the springs dont appear to be broken. i can pull both clutch shoes and the spring back.

Fuel Crazy

My Feedback: (1)

ok it has real clutch shoes & springs then.... maybe they dont have enough tension anymore. What car is this? And you didnt answer.... is the clutch still engaging at idle with the car on the ground....or only when the tires are off the ground (which is normal...)

Anthoop

LSN is too rich. Weakening the mixture will cause the revs to be higher for the same throttle gap.
http://www.rcuniverse.com/forum/fb.asp?m=10444469

buknut

Yeah it definately sounds likeyour LSN, i had the same problem 2 weeks ago, my HSN was too lean and i had a rich LSN to compensate and it was just moving all the time,
give your LSN a fiddle mate, should sort it out.

simonRC

how can i tell if the clutch is engading at idle when the car is on the ground. If you mean does it want to keep moving then yes and if I turn the trim down it stalls.

Why is it normal for the wheels to spin when the wheels are off the ground? my xtm mammoth wheels dont spin when off the ground at idle but it doesnt stall.

Thanks for your help!!

378

My Feedback: (4)

Sometimes the bearing resistance in the clutch bell is enough to get the wheels spinning when they're off the ground. My NTC3 does this. However once it's on the ground it will sit perfectly still with no brake applied.

Car-Tune

Try to tighten up your brake a tad bit more.

378

My Feedback: (4)

IMO that's not the right fix. You shouldn't need any brakes at all to keep the car stationary.

Fuel Crazy

My Feedback: (1)

i agree. If you have it applying the brakes at idle, you are probably just gonna burn up the clutch shoes quicker as they are still trying to engage and turn the clutchbell regardless.

Ive never had needle setting make the clutch engage at idle...but i guess its not impossible. Anytime ive had clutch engaged at idle was because the springs were too soft for the RPM the engine wanted to idle at.

Anthoop

My thoughts are that the engine has a rich LSN and so he has to keep a high idle speed for it to run...thus the clutch is engaging. A 1-1.5 mm throttle gap is more than enough and truth be told probably too much, again suggesting the LSN is rich.
Yes of course he could have weak springs but the throttle gap tells me that he runs at a high idle speed...maybe you and I would know that straight away by sound..maybe he does not.

Fuel Crazy

My Feedback: (1)

very possible i supose, just seems weird to me. Ive had some idle so rich it left a puddle of fuel on the ground, and would load up and die in 25-30sec.. but still did not have to idle so high as to engage the clutch. But not knowing what he has since that still hasnt been answered...its possible that the clutch springs allow for a very low stall speed and thats the reason for it.


Hard to diagnose a problem that can have quite a few reasons for it, without having it in front of you to see exactly what its doing.

Foxy

Anthoop has it, it's a tuning issue. Lean the LSN while simultaneously turning down the idle until it will stay running without throttle or clutch engagement. If that really isn't it, get slightly stronger clutch springs.

For the benefit of anyone else reading this thread and wondering why the wheels move when the car is OFF the ground; this is completely normal. However, when placed on the ground the car should stand still and idle without dying.

wmpwashing

" For the benefit of anyone else reading this thread and wondering why the wheels move when the car is OFF the ground; this is completely normal. However, when placed on the ground the car should stand still and idle without dying."" JUST SEARCH AND YOU SHALL FIND.
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