Have found everything (including engine) in spring 'hard-rubbish days' where people put stuff on nature-strip for council to collect.
But I also collect stuff! Got all metal, engine, parts free!
Only thing spent money on was the transmission, because chainsaw sprocket pitch is wrong for bike chain (although I machined it to be close),
Smallest chain and sprocket I could get cheap is the one shown.
Frame: old child's bike mixed with crappy welding to circular steel section I found. Although have since gone over welds, and now A1.
Chainsaw engine- Small- don't know power output- I think 22CC but not sure.
Currently no clutch, but in upgraded vesion (in progress- may change to a brushcutter engine) will be brushcutter clutch. So run start (which isn't too bad)
Chain Drive- 8 tooth on 56 tooth wheel sprocket: 7:1 reduction. Industrial chain- 1/2inch pitch, 1/4 inch width. $60 from Victorian Transmissions- contact: Barry.
Throttle: former gear cabling. (very neat- just thumb throttle)
No brakes as yet, with no clutch the engine slows the scooter quite well, although I have had some close calls.
Wheel size- 30cm inflated inner tube.
Top speed- 46.5km/h measured with electronic bike speedometer (calibrated and proven against car) held for 30secs along flat.
Not the best getting up hills- chainsaw power curve to high for hills- won't get good acceleration at all at low rpm- even with good mixture.
Considering using a small brushcutter engine- even if it is at the expense of big top speed.
1/2 by 1/4 inch chain, so twice as wide as bike chain.
haven't checkedİto see if same pitch as bike chain.
None the less, it is quite good and VERY rugged. It virtually self aligns, and I have never had the chain slip off (even though my set up is pretty average).
I may look into replacing current motor with a $10 brushcutter motor I have bought and fixed up.
If you want really cheap brushcutters and stuff (this guy has broken ones you can take parts from cheaply)
contact: Cheapest Mowers and Brushcutters (backyard business). 97957198... 37 Laemmle St. Dandenong.