I just got my Raptor paid off, and now they come out with a 686 EFI raptor. Now I am going to have to bore out just to keep up with a stocker [img]i/expressions/face-icon-small-sad.gif[/img]... My question for the night is, what makes a reputable engine builder? I am seriously planning on purchasing a 686 kit for my Rappy, and just letting the Machine Shop in town do the boring. What makes craycraft so good, or CT racing? Also I was advised to go not go with an ultra high compression ratio...1) I still can run pump gas on a lower comp. ration, but what does the compression ratio do to a torque curve? I do mainly trail riding, a little duning, and some local TT racing.

 

If your a competent mechanic, you can do the work yourself. I did all the work on my raptor and its been trouble free for almost 2yrs now. I would recommend a 11:1 Wiseco piston, people have been having problems with JE's and I havent heard anything bad about wisecos. I run 91 pump gas with NO pinging. High compression increases hp and trq, so you will notice an increase in power! While your tearing down your engine, I recommend that you go with a stage 1 hot cam, the stage 2 is more of a top end cam and you really dont need top end for trail riding, plus its harder on your drivetrain.

 

A good 686 kit? Craycraft I s'pose?

 

cali, i planned on a HC. Did you bore yours out on your own? I don't have the tools nor the confidence to do a bore out on my primary machine. Thanks for the reply

 

If you are looking for a good builder check out kenz cycle tech in mesa Az. They build some of the sickest bikes I have seen

 

Im still on stock bore, I didnt see a need to bore it out just yet. I just had the cylinder honed and I did the rest. If you plan on boring it out, get the piston first and take the cylinder AND the piston to a competent machine shop. You need the piston to give the cylinder the proper bore. The bore/hone should be about $30-50, have them polish the EXHAUST ports only, not the intake ports! and port match the intake boots as well, these little things help out!