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Traxxas revo 3.3, and I'm asking again before this hobby goes to the junkyard with my sanity. Then the car just revs, and the adjustments don't help no matter how much you screw them. I noticed that the tank is not completely sealed, could it be the reason that you can't get pressure, that the leak would go with it? Then the more serious problem.. sometimes the speed slows down steadily even when the gas is at the bottom, usually the car stops and the revs scream hoosianna. When you let off the gas once, it starts moving again. The car had an opti drive, I read some things online that it could cause that. I took out the opti drive, but no effect.

Hello? Welcome. Are you ok? Your post seems a bit unusual. Incoherent. Maybe collect your thoughts and write it again. A lot of hoosianna in there. Maybe some ineffective opti drive too.

The opti drives only function is to not allow it to be engaged into reverse while moving forwards. That is it. No effect on the engine just the electronics.

Frankentruck wrote: ↑Fri Jul 07, 2023 4:07 pm Hello? Welcome. Are you ok? Your post seems a bit unusual. Incoherent. Maybe collect your thoughts and write it again. A lot of hoosianna in there. Maybe some ineffective opti drive too.

Google translate apparently translated the text very strangely.

MarkyDents wrote: ↑Fri Jul 07, 2023 5:44 pm The opti drives only function is to not allow it to be engaged into reverse while moving forwards. That is it. No effect on the engine just the electronics.

So is the problem with the switch or the gears?

There would be an air leak somewhere if the needles have no real effect and the throttle is physically moving smoothly.


https://traxxas.com/support/Tuning-Your-TRX-25-25R-and-33-Engine-Best-Performance

RC10th wrote: ↑Sat Jul 08, 2023 12:20 am There would be an air leak somewhere if the needles have no real effect and the throttle is physically moving smoothly.

https://traxxas.com/support/Tuning-Your-TRX-25-25R-and-33-Engine-Best-Performance

Could the cause be that the tank is not completely sealed?

I changed the fuel tank cap gasket and at least that helped a little. But now a new problem was found, apparently the brakes are stuck, and that's why it doesn't move. How do I adjust the brakes?

I am not that familiar with nitro R/C. But it sounds like you are experiencing inconsistent engine operation/performance regardless of the adjustments made. Leaning the fuel mixture out will make the engine rev higher until the point of lean misfire and it will die. Richening the mixture will bog it down until it floods out and dies. So somewhere in the middle is where you want it. Assuming there is an idle adjustment screw and a high speed adjustment screw, you would want to turn it lean (idle adjustment screw at idle) until it stumbles, and then turn it rich until it stumbles, then turn it back just until it idles smoothly again. Same for the highspeed adjustment. It is also a good idea to run your highspeed adjustment a bit rich to keep cylinder temps down and provide sufficient lubrication. So you will sacrifice a little top end speed for a little more smoke and not burn up your engine.

If these adjustments cannot be made or "held" you might have damaged adjustment screws (needles) and/or seats (holes that the needles move in and out of to control fuel supply to the carburetor)

You could also have an air leak somewhere. Not sure if there is a gasket between the carburetor and the engine on these things....

If it was a chainsaw or a fire pump, I'd know more about it.

EDIT: what RC10th said^^^^

But if you suspect the adjustment screws have been really torqued on and tinkered with a lot, you might want to inspect the needles and seats. Shiny/polished or "necked" portions on the taper could indicate over-tightening which could also distort the seat (hole). I think the adjustment screws should have little O-rings on them also, to keep air from coming thru/around the threads.

Good luck!

From the original post broken down it does actually sound like you’re having more of an issue with the driveline than the engine’s ability to power it. Admittedly a nitro powered Revo is probably one of the most complex of all. Although it does become more simple to you over time when you fully understand what does what in the way of adjustments and performance. I’m hoping you already have the basic knowledge needed to run and use a nitro vehicle. With that it will help greatly. The next is how it’s propelled when it is running. Is the clutch assembly in good working order. If it is then is the two speed transmission working correctly. Is it adjusted properly.
These vehicles do require alot of knowledge and experience to actually enjoy using them. Without it you’ll only end up being extremely frustrated with it all together. If it’s help your looking for then I believe your going to have to explain more greatly in detail what it’s doing ( or not doing )

oldo556 wrote: ↑Sat Jul 08, 2023 12:16 pm I changed the fuel tank cap gasket and at least that helped a little. But now a new problem was found, apparently the brakes are stuck, and that's why it doesn't move. How do I adjust the brakes?

Not to steer you away but you're on a vintage R/C forum here, and the Revo 3.3 is a current issue truck in which Traxxas has a dedicated support community for: https://forums.traxxas.com/categories/revo-nitro-trucks


Also, here's the manual which should be of great help to you: https://traxxas.com/sites/default/files/5309_manual_2006_0.pdf