Hey my name is Matt and I’m new to this forum. I have had this engine that was from an old ice auger for a long time and now I want to use it for a mini bike build. I just replaced all the seals and rebuilt the carb and have it running perfect. I just have never used an engine like this before and could use any advice on gearing or anything else that mite be helpful. the tag off the engine says 670-05f. Tecumseh 6357. It was off an old jiffy ice auger. I have the gear box from it too that I was thinking I could use to gear it down. Plus the carb would be sitting sideways not sure if that will be a problem.
Tecumseh 2stroke
- Thread starter Smitty484
- Start date
I hate to say it, but it’s not an ideal engine to power a mini bike with. 3hp is usually (just) sufficient in a 4-stroke engine, but the 2-stroke lacks the low rpm torque for decent take-off. It’s a similar engine to the AH520 (found in Toro snowblowers, etc.). A quick search of that engine here might clue you in in some of the difficulties... Plus, it looks like you have a gear reducer, which would make a centrifugal clutch a non-starter if you could even fit one on what looks to be too short of a pto output stub. Wish I had better news. I have an old Tec AH520 2-stroke I’d like to do something with too, but there aren’t many options.
Thanks for getting back to me . I don’t know if this will help me but a clutch is built in that gear box. It is about a 9-1 gear reduction. I was think if mounting a sprocket to the out put shaft . i would just need a 1” I’d sprocket. I was also thinking of a scooter or something lighter. I’ve had this engine since I was a kid but I was on an old ice auger.
There are jackshaft calculators out there that might help with a sprocket decision. My first thought is to gear it low so the engine can get into it’s designed rpm’s quickly. Maybe 8:1 or so? When we set-up jackshafts, I order a couple extra sprockets that are a bit below and above the ratio I figure will work well.