Car Starts, but doesn't move

[NathanK99]

So I got this car as a gift about 8 months ago and I just now started playing with it. It's a Blur Exceed Nitro RC buggy 1/16. The car will start and everything, but when i press the gas it doesn't rev and the wheels don't move. I think the spur gear is too lose(the big gear in the middle). But there's not a nut to tighten it or as I can see there's no way to tighten it. Thanks!

 

[Certified Mike]

If it's not revving, I would be checking the linkage to the carb, the servo (to be sure it's not stripped out) and see how that is. You may want to pull the aircleaner and make sure the carb is opening when the linkage moves as well.

 

[NathanK99]

If it's not revving, I would be checking the linkage to the carb, the servo (to be sure it's not stripped out) and see how that is. You may want to pull the aircleaner and make sure the carb is opening when the linkage moves as well.

Could it still be stripped even tho the servo moves when it's on and the carb opens?

 

[Certified Mike]

The servo moves, the carb is opening and closing? Have you taken off the aircleaner and looked to see it's actually moving internally? I would guess that it's not stripped of the servo is moving... It is POSSIBLE but unlikely... There could be just a couple teeth stripped so it moves if itsjust right... Again, I doubt very much that's the issue.
I just want to make sure I have this right, so please just double check. The carb does move internally, it's opening and closing with the servo but it doesn't rev?

 

[NathanK99]

The servo moves, the carb is opening and closing? Have you taken off the aircleaner and looked to see it's actually moving internally? I would guess that it's not stripped of the servo is moving... It is POSSIBLE but unlikely... There could be just a couple teeth stripped so it moves if itsjust right... Again, I doubt very much that's the issue.
I just want to make sure I have this right, so please just double check. The carb does move internally, it's opening and closing with the servo but it doesn't rev?

Yes, the car starts, servos move and carb opens when throttle is pulled.. Its a new car and it's never been driven so I don't see how gears can be wore down.. But what would you say to do if it revs and the wheels don't move?

 

[cbaker65]

Lets isolate!...

There is a dozen reasons why it don't move ,we all know the engine starts & runs well.

1. clutch nut could be loose.
2. drive shafts cups ,screws or pins maybe loose or gone.
3. wheel axle pins are gone.
4. trans is not engagining.

With the good folks here ,I'm quite sure that we all can pic our brains to hash this out!...

 

[Certified Mike]

I would agree. The slipper could be loose. That's where I would start... When it is running, look to see what is moving and what is not. Rev it up a little with it up on a block so the car isn't moving... See if that changes what is moving. As the rpms increase, the pinion clutch should engage and move the spur gear. If the slipper clutch is adjusted correctly, the internals of the transmission should be moving at this point. Check to see if the output cups to the drive axles are spinning. If so, the drive shafts (dog bones) should be spinning. If the hexs or wheels aren't stripped then the tires should be spinning.... That is the best way I think I can describe how to inspect your drivetrain and follow it to see where the break point is.

 

[NathanK99]

When the car starts the Spur Gear Spins and the other Gear that spins with it. It's just the dogbones don't spin at all

 

[Certified Mike]

I would guess that either the gear center is stripped out of your slipper clutch is too loose. Thats where I would start anyways

 

[NathanK99]

I would guess that either the gear center is stripped out of your slipper clutch is too loose. Thats where I would start anyways

So I should go tighten the screw as much as I can that's holding all of the gears together?

Would it be better to just take the whole engine off?

Spur Gear

• NathanK99
• May 18, 2017

 

[cbaker65]

That's an open gear center diff ,so it should be easy to figure out!

With the car on the ground ,hold the car still an try to rotate the spur by hand ,the car should try to move just
by turning the spur!
If it don't ,then the axle cups are loose or there is something wrong with the center diff!

The center diff may have a o-way bearing in it ,to me it looks kind of funky ,even just pushing the car
back an fourth by hand ,it should be able to move that gear I would think!...

 

[NathanK99]

When I push the car back and forth, the gears spin and so do the dog bones, but when I rotate the spur gear itself, it doesn't move the dog bones

 

[cbaker65]

When I push the car back and forth, the gears spin and so do the dog bones, but when I rotate the spur gear itself, it doesn't move the dog bones

When you rotate the gear by hand ,does the center shaft that goes in the center of the gear move?

 

[NathanK99]

No nothing moves with the gear! I'm almost positive that the spur gear is lose because like the bearing with the spur gear, 1 bearing is off and the spur gear isn't like tight to them?

Spur Gear

• NathanK99
• May 18, 2017

 

[cbaker65]

No nothing moves with the gear! I'm almost positive that the spur gear is lose because like the bearing with the spur gear, 1 bearing is off and the spur gear isn't like tight to them?

I would take the spur off an check it ,maybe a o-way bearing in there or a pin missing or sheared off!

 

[NathanK99]

I have the engine and stuff off right now but i'm new to this and I honestly have no idea how to take it off.. It looks like something is supposed to go in this hole that will hold the spur over it?

https://www.rcnitrotalk.com/forum/a...2/?temp_hash=c5e795f1fc9d6e94f6881823824ddb2b

So I got a pin back in the spur hear that holds it to the middle drive train, but there's nothing behind the spur gear to stop it from coming off. Is there any thing I can put behind it so it can't move off

 

[cbaker65]

I have the engine and stuff off right now but i'm new to this and I honestly have no idea how to take it off.. It looks like something is supposed to go in this hole that will hold the spur over it?

https://www.rcnitrotalk.com/forum/a...2/?temp_hash=c5e795f1fc9d6e94f6881823824ddb2b

The center gears are usually made up of a spool type that has a cup with several gears in them or
one like you have that should have a one way bearing to allow the gear to free spin one way like
when you let off the throttle an brake ,its hard to tell on the pics that you show to se what it consist of.

Might have to try to download a manual an see whats missing!

 

[Certified Mike]

I would suggest the same. I did a quick search and don't see much info about the car at all. One way or another, you are going to want to familiarize yourself with pretty much everything in and on that kit. I would Def NOT just tighten everything up. Just to make certain, be sure to FIND the break in procedures recommended for that motor. You are going to need to do that BEFORE you jump in and start running it.

 

[NathanK99]

I rigged it up and now when I turn the spur hear, everything moves

 

[watertrucker]

Be sure to set your gear mesh before you run it so you don't strip the spur gear. I just cut a small strip of paper and slip it between the clutch bell gear(metal gear)and the spur gear.Then move engine over to spur gear and tighten mounting screws. There are videos on YouTube that show how to do it. And welcome to RCNT