2 speed decides not to work

I had that problem before. There is clutch inside your tranny that when you get to a certain rpm it pops out and grabs second gear. You need to do some work in there. I'll get some pics...

Here are the pics.....

Thanks to Glenn Roberson for the pics/instructions...

Here are the pics. This is the shift arm as it would extend to shift into second gear. The tip of this is what gets mushroomed as it extends out and slams into the pin of the higher gear.


This picture is where RiverRevo bevels the inside edge of the groove that the arm fits down into. This is so that if it does mushroom, it won't get stuck in the groove during a race. Then after a race weekend or before the main you can pull the tranny and file down the tip of the arm if it is mushrooming. Usually seems to happen with high torque motors (tz's) or with the wide ratio gear sets as they seem to shift harder.


Its a simple thing to do. It takes a few minutes to do but well worth it!

thanks for replying quick, but, i dont quite understand what i need to do.

you say bevel somthing?

can you explain whats happening?

sorry I'm a bit confused, i know how the 2 speed shifter works, but i dunno what i need to do.

sorry, bit of a dumb momentpps:

In the first pic the part that is sticking out is what hits the pin that is tied to your second gear. What has happened is that the pin has hit so hard so often that the tip of it flares out and gets stuck. It gets stuck in the second pic where its highlited red.

You need to make the slot larger (second pic) and make the black part skinny again. Its been a long day at work so if your still confused don't hesisate to ask.

right cheers for being patient mate.

is it just a matter of filing down the red bit a bit? or file down the 'shoe' so its thinner?

and then just re install?

if so that doesn't seem hard.

also, is it just getting stuck because the show has kinda 'spread' thus like you have siaid it gets stuck? so its jsut a matter of filing down the shoe? or will the problem re occur in time?

Thats why you file down both. I did it and haven't had the problem reoccure yet.

ok cheers bud.

the strange thing was that the shift kept getting later, then was fine for 2 high speed runs, then whent late etc etc..

so i truned it off for about an hour, started it back up for a run, then it was fine, for nearly a tank, then it just packed in alltogether.

reckon you can explain why it did that? dont mean to be perssistant, i just like to know why it did it, helps me learn

When your hard on the throttle and shifting from 1st to 2nd that shift arm comes out and slams against this pin (see pic) Its the same concept as taking a nail and trying to pound it into a piece of steel. The tip is going to flatten out.

see the pins on the big gear.

I'll ask just because, but what were your engine temps? If your running fat (rich) and the temp is too low, it won't shift either.

right, i fully understand you now (after that severe brain lapse).

hope you dont mind but I've linked this thread to help some other guys out on another forum.

jetmechG550 said:

I'll ask just because, but what were your engine temps? If your running fat (rich) and the temp is too low, it won't shift either.

Click to expand...

its running bang on, temps around 230 240.

wheelies on,low end, nice amount of smoke on topend.

its definatly somthing to do with the gearbox, but, i will adjust the shift point a full trun earlier, just to make sure.