BWS100 4VP parts in 1E40QMB

[vlatx]

Hi guys,i want to do a conversion from 50cc to 100cc on 1E40QMB engine cases.Can it be done with crank and cylinder kit from BWS100 4VP engine, can i use the oem 16mm variator and ignition system.I know that i have to bore the cases.

[90GTVert]

I don't know if 4VP is anything special, because I never got that far into any BWS100 info... but the cylinders for the 100s should have different stud spacing and the cranks use different bearings and seals and are very large diameter so the cases would get really thin and may require other work. If you really want a 100cc with a 1E40QMB, get a 45mm stroker crank and a 54mm bore and that'll give you 103cc. You still have to cut the cases for the crank and cylinder, but they don't have to be cut away so much.

[aeroxbud]

I think it's a non starter. John said the same thing as Brent in this thread 49ccscoot.proboards.com/thread/28521/stroker-117cc

[vlatx]

Ok thanks guys,il go with Stage 6 sport pro mk2 next time i do a rebuild.

[repherence2]

You can always pick up a minarelli ATV engine. The one i got came with a Yamaha cover on the CVT and the jug was stamped 83cc...i dunno if its a genuine Yamaha because i bought it from a scoot shop operated by Chinese. Im pretty sure you can get by with a Polaris 90 engine as well.

My Chinarelli was imported with Ruima 12 pin, big spline, big taper. My CVT stuff crossed over to the 83cc engine as well, the Jog90 stuff. The 45mm stroker crank might be set up for jog50 trans and flywheel. You could build it however you want. The Polaris would already be bored out for the Jog90 crank and bore so you wouldn't need to do any machining.

A shop tuner/mechanic once told me, "just get a 90cc SMC Rex (jog90 but from Taiwan) block, put an upgear kit in it and you'll be able to run with the Dio's all day. Strokers and all." He was right! Oahu has some fast "Dio's", but the Jog90 defeated all but 1 that called me out on the "streets".

[repherence2]

**delete double posted.