Clutch Problem???

[Matt270]

Hi guys,

I am fairly new to nitro cars and seem to have a bit of a problem:

The last time I used the car I seemed to have the engine tuned nicely - the car went like a rocket with a decent amount of blue smoke coming from the exhaust, however, I have used it today and don't know what's happened......

The engine sounds like it's running fine, revving to a nice high-pitched whine although the car seems seriously down on power. When at full throttle the engine sounds good but the car is way less than half the speed it was last time I used it. Set-up is exactly the same, same fuel, HSN and LSN settings the same etc....

The car does seem to rev pretty high on idle and wants to creep forward and I cannot turn the idle screw in any further as it just stalls all the time.

Could I have a worn clutch as I can't see any other reason why the car wouldn't go as fast as before when the engine sounds the same????

I've checked that the spur gear is still in contact with the motor and it seems fine - no excessive wear etc....

Can anyone help pleeeeeease???

 

[MotoGod]

Could definitely be a worn clutch, but your tune may also need to be adjusted, especially if the temp difference between the last time you ran it and this time is drastic.

Check the clutch though....

 

[ThunderTiger]

FIRST UP, your idle. You want a 1mm gap between the carb slide and the carb opening, anymore than that and your idle will be on the high side.

SECOND: Check the clutch shoes, it sounds like they may indeed be worn from that high idle speed you have and the car wanting to "creep" forwards.

Check for binding in the drivetrain as well. It could cause the rig to run slower.

 

[2revo1maxx]

Could also be the slipper. And it sounds like your low needle is lean. Also try just spinning the spur with the engine off, it should spin one way or the other with very little resistance. That will tell you if you have a bad clutch spring, a broken shoe, or bad clutch bearings. The shoes are probably fine, unless they wore down while it was sitting

 

[ThunderTiger]

hey,2revo........you stalking my posts ?lol

I see your point about the slipper being loose tho........

 

[2revo1maxx]

I'm just messin with ya...sorry.

 

[ThunderTiger]

no worries, cameraderie and fun make this community!

 

[Matt270]

Thanks again guys for all your speedy responses. I'll check that the spur spins later today, then the only problem I'll have is actually trying to repair whatever it is that's broken!! I'm not bad at fairly routine repairs but I think a trip to the model shop might be in order for the clutch, I wouldn't have the first idea where to start!!! Lol

anyone kno of any guides that might save me some cash?

Help appreciated as always

 

[2revo1maxx]

What kind of car is it anyway? I guess if you're not sure about fixing it then a trip to the lhs isn't a bad idea. Pay attention to what they're doing, you don't wanna have to keep going back.

Also try the owner's manual if you have it. The clutch info might be in there.

 

[Matt270]

Thanks mate. It's a Thunder Tiger Tomahawk BX buggy. I think I might have to go to the shop as the clutch doesn't seem to be detailed too well in the manual. Do you know if it's likely to just be the clutch shoes or whether an entire new clutch assembly will be required?

 

[2revo1maxx]

Try spinning the spur first, it might be fine. If it doesn't spin freely one way or the other then the clutch is probably fine. Did you try tightening the slipper clutch? That nut on the spur gear. Just an 1/8th of a turn or so should do it.

 

[ThunderTiger]

aaaaaaah, ia t/tiger ! why didnt you say so before ?

Check the drive shaft6s are still tight on the diff out drives running from the centre diff, failing that, check the rest of the diff cups and the driveshafts to make sure the grub screws are still tight and failing that, check the diffs.

If the tomahawk is anything like the EB4, the grub screws on the drive shafts and drive cups are prone to working loose and the diffs will need checking as well.

 

[Matt270]

Ight guys, thanks again for the advice. I think I've traced the problem to the rear diff. When I lift the rear of the car and roll it along on the front wheels, only one rear wheel spins. Also, if I lift the front and roll it along on the rear wheels, the fronts don't spin at all. All the drive shafts seem to be properly connected so I'm guessing somethings wrong with rear diff.

So I checked the grub-screws as advised and one was really loose! Tightened it up and now all wheels seem to spin correctly. Could that have been why it seemed so down on power? Now I come to think of it-the last time it was out it was slightly intermittent. Every now and then it did seem to have a surge of power and then it would go back to being mediocre again-I'm wondering if now that everything's tight it'll be ok. Might not get a chance to try it today so hopefully tomorrow I'll find out.

I'll let u know what happens!! Cheers guys

 

[2revo1maxx]

Could be the center diff too. It might be out of oil and unloading to the front wheels when you take off.