Force .25 stalling problem

[d_cavana]

I have a GV Leopard with a Force .25 engine which has been running great up until yesterday.
It will start fine and run well from cold, when it warms up a bit it stalls making a strange clunking noise & the truck jumps forward. It will then start after a few pulls and it revs fine and has plenty of power, but i need to keep the revs quite high or it will make the strange noise, stall & jump forward.
I have spare engine for the truck, but dont know if its worth changing, or could it be something simple?

 

[w bill]

Grab the flywheel and see if you have play in the bearing also take the clutch bell off and check your cluctch springs lets go from there prosses of elimination.

 

[d_cavana]

Ok, I checked the flywheel and there is no sideways movement, but if when I pull it, it will move away from the engine very slightly (1mm). I checked my other engine which has the same movement.
Clutch bell off, springs and clutch are as they should be.

I had it running again 10 minutes ago and it will idle perfectly, after a minute or so - clunk and jump forward.
I did notice a strange noise on the first 2 pulls when re starting it, almost like a grinding noise but when started and revved it was totally fine, but back to idle (Quite high idle) same thing happens.

 

[w bill]

About all i can say at this point is a total tear down check all the internal and starter parts for wear. If your idling high your probally sucking air.There is a thread on how to seal your engine if you dont know how to. Go online and get an exploded view of your engine it could even be a bearig that is going bad the rear one.You won't know till you get it apart wish i had a better answer for you.Run the engine without the clutchbell or shoes make sure its not your gear box.

More i think about it I'm starting to lean toward rod or rod bearing.Hard to say without seeing it.

Just change the engine then figure out what is going on with that one.

 

[10 Gauge]

I would be checking the conrod bushing/bearing, sounds like it could be tired.

 

[Jacknifejuv]

I have a gv leopard in my shed with same spec great little truggy you buy it brand new ? I've always had problem's with my clutch bell for some reason . Have loads of upgrades if your interested .

 

[d_cavana]

I ran the engine with the clutch & clutch bell removed, it was far better, the clunking when stalling noise has gone.
The clutch & springs look ok & there didnt seem to be a clutch issue when driving the truck. I did notice that when I removed the clutch bell, there is an outer bearing but no inner bearing. It should have both according to the engine manual, could this be the cause?:\

I have a gv leopard in my shed with same spec great little truggy you buy it brand new ? I've always had problem's with my clutch bell for some reason . Have loads of upgrades if your interested .

Bought it second hand, barely used. I do love it, beats my mates Savage X. I will be interested when I get it sorted, cheers

 

[10 Gauge]

I ran the engine with the clutch & clutch bell removed, it was far better, the clunking when stalling noise has gone.
The clutch & springs look ok & there didnt seem to be a clutch issue when driving the truck. I did notice that when I removed the clutch bell, there is an outer bearing but no inner bearing. It should have both according to the engine manual, could this be the cause?:\

lol, yes. That most definitely probably is your problem. Without the inner bearing your clutch bell will not sit straight on the crankshaft. It could be binding up on you and that's whats causing your motor to stall.

 

[Jacknifejuv]

Yep wen i bought mine brand new there wasn't a inner bearing as well . Mine has the standard disc wheels . There really fast especially wen you get them tuned right there not so much of a jumping truck but they do go some . You can get quite alot of hop ups as well with Gv .

 

[w bill]

lol, yes. That most definitely probably is your problem. Without the inner bearing your clutch bell will not sit straight on the crankshaft. It could be binding up on you and that's whats causing your motor to stall.

I'm with 10gauge thats the first thing i would fix put new springs in anyways even though they look ok they can be weak and when they heat up they open even easier. Its a good starting point let us know what happens.

 

[d_cavana]

New clutch, springs and bearings have been ordered.

I'll let you's know the outcome.

Thanks for the help