Vader 125 Engine Internal Specs
 

After about 200 miles of riding the Vader, I am really itching for more power. The bike struggles to maintain 50mph going up big hills with my 250lb self. So I decided it would be a good idea to start a new thread outlining the engine specs for anyone looking for more power through a high comp piston/big bore kit/race head. What I've gathered so far without taking the engine apart:

Engine: BD 1P54FMI
Piston Diameter: 54mm
Wrist Pin Diameter: Unknown (someone please chime in!!)
Stroke: 55.5mm
Cylinder Jug Height: 78mm
Head: Appears to be a big valve YX head (similar to YX140)

It appears a TBolt USA Big Bore kit for a YX124cc engine should work, as well as the Race Head for the same engine. I am unsure if the head is, in fact, a big valve head. I know a few people have taken them off so hopefully someone measured the valve and combustion chamber size!

Please share any info you guys have on this topic here and I will update the first post :tup::thanks:

Gotta know the stroke, piston pin size, type head needed. I'd compare the cost and time doing all tgis to the stick engine to buying a 160cc or bigger engine.