Tecumseh HS50 and Carburetors

[zimmerkm]

I recently restored a Rupp Roadster 2 mini bike. Part of this project was to use a NOS HS50 motor. Since the motor was originally for a snowblower, I had to find a slant intake manifold to mount the stock carb. It would run great at slow and medium speeds, but would completely fall apart at high speeds. I would get an initial surge of power, but then it would fall apart, like it was running out of fuel. A friend suggested that I replace the carb with a Honda XR75 carb. I found out that the intake I found and installed appears to be a H30/35 slant intake. I'm trying to determine if my issue is with the intake, or should I replace the carb. Has anyone installed the H30/35 intake on a HS50. If so, what was your experience?

 

[jeep2003]

Curious what others have to say but is it breaking up or just bogging out? If its breaking up it could be electrical either tired coil or points. Or tired valve springs causing float. If its just bogging out id say its more likely a carb issue.

 

[ruppking]

The H30-3.5 slant intake will not properly bolt on your HS50 engine. The HS40 intake will bolt on, but may have a small gap open on your HS50 intake port, which may be your problem. The proper HS50 slant intake will have the same port shape as your engine intake port.
If you have the correct intake, then I think you have a carb problem. Either tuning the carb or a rebuild should fix the problem.

 

[cfh]

you can make an intake for a slide carb. it's the best solution. i just made this one today for my Speedway Scarab. It's an HS50 (slant obviously) with a big cam and an open exhaust that i also made. The motor is a late model Tecumseh HSSK50 from a snowblower I believe 1998. You can have the engine and carb intake plates made at sendcut.com, and i used 7/8" stainless steel tubing from Zoro.com. The carb is a 22mm slide pz22 i bought off ebay for $18. Amazingly the current crop of pz22 carbs come jetted correctly!
http://www.pinrepair.com/minibikes/p/speedway1973scarab_mine1.jpg