Engine Air Leaks

[Skwerly]

Hmmm, ok. Where is the "backplate" that has the o-ring on it then, on the 2.5 engine? I wanna seal that up good and possibly cure an air leak. I googled 2.5 backplate, and the pictures are of something I haven't seen before haha. Is it under the pullstart?

 

[Scrogg]

Yes it is.
The most common air leaks on the Traxxas's is the header seal and pipe coupler, fuel tank lid O-rings.

 

[olds97_lss]

Hmmm, ok. Where is the "backplate" that has the o-ring on it then, on the 2.5 engine? I wanna seal that up good and possibly cure an air leak. I googled 2.5 backplate, and the pictures are of something I haven't seen before haha. Is it under the pullstart?

When you take the ez-start/pullstart housing off the back of the engine, you will see a shaft that the one way bearing spins on. The plate that the shaft goes through into the engine is your back plate. They are known in general to leak around the perimeter of the crankcase where the plate and case meet.