Recent content by Proptimus Prime

I built the motor this winter, the head came off of a 650sx top end that was 1.5 MM over bore and the compression was 165 in each hole, i bought a pair of HPR ported cylinders this winter and had the local machinist put new sleeves in them and he returned them to stock bore. I didn't think about...

My compression is at 210 on my 650sx, i just build a brand new motor this winter and i have no idea where to start on jetting it.i have dual mikuni 44's and i have no idea where to start on the jets. Where did you guys start? what octane were you using?

Awesome! thanks everyone for your advice. I will take that into consideration. Wish me luck this weekend!

I just really have no idea where to go from here. I have a new motor with 210 compression and i have 2 carbs and a single and double intake manifold. I don't know :-):-):-):-) about jetting, and everyone is telling me different premix ratios. I am so unsure about what to do it's ridiculous!

My altitude is 702 ft (214 m) " Minnesota" My older motor was 165 and I knew it was going to go up with a fresh top end and stock bore i just didn't think it would go past 180. I didn't check it before I went out. I figured i would only have to tune the carb a little bit. lolol Clearly i was...

Hey guys, this winter tore apart my old 650 motor and have replaced every part with any upgraded parts I could get my hands on. I bead blasted and powder coated just about everything I could. Bottom line My new motor is a ported cylinders with new sleeves on a stock bore with a high...