I can't get my MT to shift into second. I have taken the spurs out a couple of times and checked everything out. It all seems fine. I have the adjustment screw turned out about 4 turns. I started at 1 turn and worked my way out a 1/4 turn at the time. I didn't go any farther b/c it started to feel loose and I didn't want it to fall out. It hasn't shifted since I have owned it for about 3 months now. I switched from the MT tires to some Proline Dirt Hawg AT tires that are a lot shorter. You would think with the lower gear ratio from the tires it would shift early but still nothing. I am kind of wondering if it is in second gear to start with. If I remove the engine are the gears supposed to turn together or seperately?

they move together but will engage at different times... check to make sure you are turning the correct set screw for 2nd gear... it is the angled one not the straight one.. start in and work out... not the other way around... I don't think the tires are the problem.. I believe its the 2nd gear setting or the engine isn't tuned for speed... When you said you felt the screw was loose and was starting tome out, I think you may be working with the wrong screws... let me know...

I am adjusting the right screw. THe one with the spring under it. If you turn it out too far you will lose the spring tension. It may just be a worn out spring.
I forgot to mention, I can hold it in the air and it will shift and hard. I was kind of wondering about the tuning myself. I am running it in my yard. I have a pretty big side yard with a little over 100ft to work with. When I mow that side of the yard I scalp it so the grass is only a 1/4" tall at the most in some places. I would think with the smaller tires it wouldn't take but about 50ft for it to shift.
I am running the LSN at about 1/2 turn in from flush. The HSN is somewhere between 2-1/4 and 2-1/2 turns out. The truck seems a little slow on takeoff and but it doesn't rev up and bog it just revs up a little slow. If I turn the HSN in anymore the engine gets too hot and I have to fatten it back up again. Right now I am just using the spit test to check temperature but I will bring my temp gun home from work tomorrow and get a real temp reading.

There are 2 screws the 2mm wrench size that is the set screw and the 1.5mm wrench size adjustment screw.
Another thing to check is to make sure that it is installed the right way.

Here is a scan of the assembly sheet. You might need to save the pic and use another program to enlarge it to see the detail.

How long have you had the truck... another possibility is the little arm on the shifter isn't engaging the gear.. Mine is doing that right now, but since I don't need the speed, its not a problem.. the reason for my problem is the lip on 2nd gear is worn smooth so the arm misses it.. I have many more gears, just not in the mood to change it right now...
You said something interesting.. It will shift when you hold it up... leads me to believe that your problem is tuning related or maybe...... running on grass... even with my engine running great.. it would rarely shift in the grass... even short grass and you are only running a short 100 feet...

I have owned it for about 3 months. It wouldn't shift even on pavement when I first got it. It was screwed all the way in and I knew that wasn't right b/c I have the original papers that came w/ it. I turned it out a little at the time and couldn't ever get it to work. I put new spurs in it about 5 tanks ago b/c a rock caused them to strip but I didn't see anything wrong w/ the tab on 2nd gear at the time. I am mostly thinking it is a tuning issue now. I took it out yesterday on the street in front of my house and ran it straight for about 100ft and it started veering right so I tried to straighten it and it flipped over so I gave up on that way of testing.

Ahhh the dreaded torque steer to the right.... Just adjust your trim a little to the left and it should help... also, don't floor it right away, ease into the throttle a bit.. gives you more control.. I lowered my truck to help prevent flipping over.. Keep adjusting the tuning.. I think thats what it most likely is..

If I am using a hand held temp gun exactly where on the engine should I be pointing it? I ran a tank through this afternoon and checked the temp 3 times and it was between 240F and 260F at the bottom of the head. I think that is about the right temp but not sure if I am checking at the right spot.
Oh yeah, I am running 20% nitro if that changes anything.
Yeah, I adjusted the trim on the steering to keep it straight. I forgot to take it slow and check after the transition from grass to pavement.

I don't tune an engine for temp as you are doing because you may not be reaching the full potential of the motor... Tune for smoke and sound... you want a little smoke trail and alot of rpm's.... I use my venom temp meter to check and see where I am... thats all.. If you are getting the full revs from the motor, then your problem lies in the shift mechanism itself.. make sure you turn the screw out from down... also, you may have to take apart and make sure the gear for 2nd isn't worn out on the inside... lastly, make sure the shifter arm isn't installed backwards... its very easy to do..

I thought if the engine got too hot it would toast the cylinder. Maybe I just need to lean it out more. It takes off from a stop good now almost lifting the front tires. There is a steady stream of blue smoke coming out but it looks a little thick to me. I was just trying to keep it under 260F b/c I heard somewhere around here it was a good temp. to run.

your on the right track to engine tuning... just make sure there is smoke... check the temps anyway... should not go ever 290 ....

Gonna have to tear it down I guess. I ran a tank through this afternoon. I leaned it out and let her fly. When it tops out there is a loud ratcheting noise and it doesn't shift. Thanks for all the help fellas. I will tear into it again and see what is going on. Sounds like the arm is just slipping to me. Guess I will see.

There is also the possibility that the set screw has backed of enough to cause the shift unit to slip on the shaft.

The most common place to check the temp is down the hole to the glow plug. The glow plug area is going to give you the most accurate reading.


rolland

Well, I pulled the 2spd apart. Here is the problem. The bearing on the 2nd spur is worn causing the spur to wobble a bit. This caused the arm to slip around on the inside of the spur and not shift. Guess that was the ratcheting sound I was hearing when I topped out first gear. Thanks for all the replies guys.

glad you found the problem and also that it wasn't engine related...