3.3

[Munstakwi209]

I just bought a new revo 3.3 not at all new to nitro but can't seem to get a tune on it i noticed it winds up fine but doesn't shift and every now and then the idle fluctuates any ideas? i don't see how it can be an air leak brand new engine

 

[cbaker65]

I just bought a new revo 3.3 not at all new to nitro but can't seem to get a tune on it i noticed it winds up fine but doesn't shift and every now and then the idle fluctuates any ideas? i don't see how it can be an air leak brand new engine

I don't have a Revo ,but you might can check the spur an make sure that it is tight enough!

 

[Munstakwi209]

Ok i'll do that pardon my ignorance but how do i check the spur gear?

 

[cbaker65]

Ok i'll do that pardon my ignorance but how do i check the spur gear?

The clutch bell off the engine meshes with the spur gear to transfer power to the drive train ,the spur gear should
have a nut with the spring on it ,if that is not tight enough ,it will slip!

 

[Munstakwi209]

Ahh ok I think thats whats happening how do i tighten it with the engine in?

 

[cbaker65]

Ahh ok I think thats whats happening how do i tighten it with the engine in?

Well ,that is only if that is the issue ,if your engine is revving high an the truck is barely moving or struggling
to move ,it could be other things as well!

So at this point ,you should check them out ,here is what I will do ,over all ,you want to turn the radio gear on ,after
that ,with out engine on ,push the truck by hand ,it should move freely with out restrictions ,then try it while applying
the brakes ,it should stop ,release th brake an see if the truck moves with out restrictions ,ok ,if that checks out good ,
then there is no issues there ,that means that the brake linkage is set good!

If the engine has not been tuned after break in period ,it may not be enough rpm's to make the transmission shift!
If that is the case ,then I suggest to lean the engine in some to see if that will help!

If those check out find ,you can check the spur nut an see if it is too loose ,there maybe a cover that you may have
to remove ,an again ,I dont know the layout of your truck ,my truck is open in that area ,but all nitro trucks should
have a slipper spur ,as that is what saves the transmission from the stress ,so there should be a spring loaded nut
that holds the spur gear on!

It should be tighten all the way down an then backed off about a 1/8 turn or so!

Also ,if your truck is new ,then you may need to run it for awhile through some break-in time!

 

[olds97_lss]

On the revo, they had 2 kinds of tensioner on it. One was using opposing belleville washers, the other used a spring. If you have the belleville washers, don't tighten it all the way and back it off, it will smash the washers, then they are useless. If you have the one with the spring, then you can tighten it until the spring fully compresses, then back it off 1/4 turn and work from there.

 

[Munstakwi209]

i did all those checks breaks are fine moves unrestricted but the spur gear spins freely in place and doesn't seem to engage the transmisson i can't seem to get to the spring the engine backs right up to it

 

[Munstakwi209]

I start the truck give it gas and the spur gear just spins in place truck doesn't move

 

[cbaker65]

I start the truck give it gas and the spur gear just spins in place truck doesn't move

Does the truck have reverse?

 

[Munstakwi209]

Does the truck have reverse?

Yes it does but i think its the spur gear it just spins like hell and the truck doesn't move

 

[cbaker65]

Yes it does but i think its the spur gear it just spins like hell and the truck doesn't move

The spur gear & the shaft spins together?

I asked about reverse ,because if it has reverse ,then the trans can be stuck in between the shifting point an
in a neutral stage!
I dont know your truck ,so if you have a servo that operates the shift ,then it could be out of adjustment an
not engaged in the forward gear!

 

[olds97_lss]

Since you were kind of questioning the slipper, can you see if you still have all 3 slipper pads? If it was loose and you didn't know it, it could have slipped a lot/overheated/thrown a pad or two, then you will have slipper problems regardless what you do until you fix it.

I had that happen on one of mine once. I replaced the 3 pads with an old savage or t-maxx fiber brake disk I had laying around. Worked pretty good.

 

[Munstakwi209]

Turns out I was going the wrong way when trying to tighten the nut got her all good now,now I need help tuning her so she shifts

 

[Munstakwi209]

I think the low speed is set i pinch the fuel line it speeds up then dies i gotta work the high speed i take it?

 

[cbaker65]

I think the low speed is set i pinch the fuel line it speeds up then dies i gotta work the high speed i take it?

If you can punch the throttle real quick on take off ,an let off with out it dying ,then it should be good ,however ,
as you lean the HSN ,you may have to slightly change it ,if your getting a nice peaky sound at full throttle runs ,
then your Hsn should be good as well ,but you should run the Hsn a little bit rich!....

 

[Munstakwi209]

Doesn’t quit wheelie but doesn’t die when I let off also doesn’t seem to shift??

 

[cbaker65]

Doesn’t quit wheelie but doesn’t die when I let off also doesn’t seem to shift??

Again ,I don't know your model like Olds97 does ,my truck wont shift unless the engines RPM's are right ,
but mine also has a t screw were I can change my shift point at a lower RPM rate!

Olds97 would know if that model has the adjustable shift point!....

 

[Munstakwi209]

Yeah it does it has a slot to adjust shift points

 

[cbaker65]

Yeah it does it has a slot to adjust shift points

OK ,mine ,to make it shift early ,I would back the set screw out ,it only takes a little turn ,maybe an 1/8 turn at a time!
You dont want to take the screw too far out an get the screw use to going that far ,mine has a tiny spring & ball inside ,
so if the screw is constantly messed with ,it can vibrate out!

So ,only make small adjustments ,an trial run after each until it starts to shift ,you will notice when it does!