Scooterotica

i want to build a engine to to pull a lammy with a side car , want something with a bit of power to keep up with modern traffic speeds , would a stage 4 200cc with 125 gear box work , if so what front sprocket and rear sprockets would work best , cheers :freak:

i think youre about right there in theory. HOWEVER i ran the last sidecar i did with a bog standard sx200 engine and it ran all the way to the south coast and back with no issues. gearing was motorway good for 50 mph + cruising, watsonian bambini + sx + 2 people + luggage and seeting off uphill was only a little feathering of the clutch, i suspect all this lower gearing malarky is a lot of people who have never run a set up like this daily except from their armchairs. maybe a 150cc barrel WOULD struggle without gearing adjustments but the 200cc sx never really felt like it needed lower gearing even on steep hills.

I ran my series 2 with bambini on a standard gp 200 engine and it would die if it even saw a hill coming ,good on the flat for about 50 but had to gear down constantly to keep it there,, i fitted an li 150 box and it was way better, cant remember whether i changed the clutch sprocket or not..

Final drive ratio on the LI150 and the GP200 is the same. LI 125 box would be about right for a stage 4 200 engine giving a "revved out" top speed in the mid 50's and safe cruise of about 50 mph.