Revs but no movement.

[Blackout]

After my last short bash I noticed something was wrong at the end when I hit the throttle and nothing happened. Today my fears came true and the engine revs but there's no movement.


I have taken the engine off and looked at the clutch but to be honest I probably wouldn't know if there was something wrong even if it was staring at me in the face.


One thing I'd like to ask is though is about the clutch bell. Does this move freely without moving the gears at all or is it supposed to move back and forth with the gears? Mine is moving almost completely freely if I spin in.


Thanks.

 

[cordy]

Ok check that your drive cup set screws are tight thats where the dog bones go into your differnials.When you look at your cltch make shure your spring is not broke.

 

[Blackout]

Ok check that your drive cup set screws are tight thats where the dog bones go into your differnials.When you look at your cltch make shure your spring is not broke.

The spring is definitely not broke. The drive cups seem to be okay as well since they all move as they should when I move the MT back and forth.

When I move the MT back and forth the clutch bell does not move, is this normal?

 

[Mike6000]

I agree with Cordy in that you should check your drive cups, they're usually the culprit there's 4 on the drive train alone, and just because they appear to be spinning when u roll the vehicle doesn't mean they're tight check them thoroughly, especially if u already have the engine off and inspected the clutch assemble and bell. Other than that check your trans gears, if u turn the clutch bell by hand your car should move forward. Hope that helps.

 

[Ildy666]

Check where ur clutch bolts to the motor that bolt is known to loosen up and then ur clutch is not engaging.

 

[Deluge]

The clutch bell should move when you roll the truck. One of the square drives on the gear plate might be loose or stripped. The gears ride on these square drives and if the set screws loosen up or strip, the gears will slip.

Here's a visual...

 

[Guest]

You should be able to roll the vehicle on the ground with little resistance. If you can't the issue is in the drivetrain.

 

[andyken]

Could be a set screw on the brake/drive shaft.

It's a two piece shaft, see if the bevel/pinion gear moves and the gears on the plate...

Try holding one wheel and turn the opposite tire and watch the dog bone cups for slippage.

 

[ocy9]

You should be able to roll the vehicle on the ground with little resistance. If you can't the issue is in the drivetrain.

or stuck brakes.

the last time i had this issue, it turned out that my brakes had melted and gotten stuck. the end result was the same... i had revs but no movement, and the car wouldn't roll freely on the ground.

 

[Blackout]

Here are some pictures.

Below these two screws were loose so I believe that to be the cause as to why the clutch bell was able to spin freely without moving the gears with it as it should have. Hopefully this was the problem as it's an easy fix.

 

[Guest]

That will do it. You might want to check the rest of the squares. Don't forget the thread lock.

 

[Deluge]

Here are some pictures.

Below these two screws were loose so I believe that to be the cause as to why the clutch bell was able to spin freely without moving the gears with it as it should have. Hopefully this was the problem as it's an easy fix.

There are two flat spots on that shaft, make sure the screws are lined up with them before you tighten them. I'd clean out those threads, as well. Thread lock doesn't like dirty threads. Red or high temp thread lock would be best in this area due to the heat from the clutch being transferred through the clutch bell.

 

[Blackout]

Just tried it in my room, the truck now goes forward. I was surprised with how far in I had to press the throttle to get it to move though. Either that is normal and I just played with my Losi 8e last which is why it feels different on the throttle or there is something wrong. I was hoping to take it to the park today to test it properly but rainy UK never lets you down when it comes to the weather ARGHH!

 

[Deluge]

How's the tune on it? Acceleration will be poor if the low end is too rich. Plus you have a low RPM clutch spring in there, so it's naturally going to bog a bit.

 

[Guest]

The factory clutch engages at 6000 rpm.

 

[Blackout]

Just tested it again in the garden. It is definitely moving forward which is a very good thing. I believe I just got use to the Losi 8e throttle as it moves with the slightest bit of throttle so then going back to the truck it felt way different and got me worried.

 

[Guest]

Good to hear you got it sorted.

The electrics have instant torque. They do move with just a touch of the trigger. The gassers need to get up into their power band or they would stall or bog down.

 

[Blackout]

Had a proper test with it today in an open field, everything was fine. After about 25 minutes or so the truck shut down, got home and had a look. The fuel tank caved in, forgot to take the lid off and let some of the pressure out.

 

[BertR]

Wow.. your carb must have better suction than a 20$ hooker at a interstate truck stop!

 

[Guest]

Wow.. your carb must have better suction than a 20$ hooker at a interstate truck stop!