Uh yeah, about frame breaking. Here is another good place to gusset.

I am a firm believer in,
"You can't have too much fun!"
This post could make me question my belief.

There are a few options available. The easiest is to purchase a complete new top end from HPI if they are still available. That's the route I took. Or you can do as Victor suggested and use a combination of bottom end pieces that will allow you to use a model 97 piston. A third option is the Nicasil...

Ride proved successful, hallelujah!
Not quite there yet but much much better.
I think I psyched myself out by adjusting every which way over and over before I sent it to Greg.
I am learning a new respect for 1/4 turn adjustments.
Time for 1/8 turn.

Thanks Olddogs!
The entire shift case rebuilt, and wheel off the ground gently rocking back and forth.
I am doing the trial and error method now. 1/4 turn clockwise and I can engage each gear. Going to go for a quick ride.

During my initial test rides I had trouble finding 3rd and 4th so I sent the cover to Greg for a rebuild. Got it back and it looks great! He set it by the measurement method so I have not tried to change it. With the cover off and tire in the air the control shaft seems to find 1st 2nd and 5th easil...

From my Wombat manual

Dale, I need to trim the bottom of the aluminum stock so it follows the contour of the engine.
Just looking at my hacksaw gives me arm pump! I need to take it a shop with a bandsaw. Then I will see if it will fit a CW frame.

I have a 95 engine slowly going together but I do not yet have a shift cover for it. I read that an older cover would fit on the 02 and 03 so I wondered if it could work the other way. The screw hole near the shift shaft lines up. I fitted a piece of aluminum stock to the mounting hole at the bottom...

I went to install the 91R trans into a 95 case and ran into an issue. The collar on the 91R kick gear is appx. 2mm taller. It causes the trans to bind when cases are tightened.
The solution appears to mill 2mm off the collar. Am I missing something?

So I cut the spark arrestor off the donor 03 pipe and cobbled it together. Made some improvement but not enough yet.
I am sidetracked for a bit as I am sending the shift cover to Greg for a rebuild.

Thanks Matt!

My initial impression is that this is too much of a good thing. The engine runs better in the mid range with an 03 pipe. Now I only have a couple heat cycles in so I can't tell much yet.

Much easier on the eyes now!
Looking good!

Looking at the seams show where I rotated the pipe.

Victor, A sawzall and duct tape. I started by looking at 125's with a center port exhaust. Then went on ebay and looked for the least expensive pipe I could find. I held the main section as close as I could get it and guessed where to make a cut. Did that twice. Then fitted it to the connector from ...

I like the typeface, clear and easy reading. The white background is bright which is a little hard on my eyes. Maybe I should turn down the brightness on my phone Lol.

https://youtu.be/OJ0tWDlrHrk

Link to you tube video

I can't figure out how to post a video but it runs!!!!

Progress report.
Engine assembled and installed.
Massaged 99 YZ125 exhaust test fitted.

You would need to figure out a way to lubricate the right main bearing.

Great story Albert!

One on ebay now. $24.99

Search;
Hodaka Ace 90 workshop manual 1967

Mine

Ed,
I agree there shouldn't be an issue with the spacers. However since they are under $2 ea. it would be an inexpensive way to eliminate them from the troubleshooting process.