Intalled the 686 kit about 2 months ago and it has been working well since just recently, I havn't been on it in 2 weeks. Took it up to speed wot in 5th and it felt like some what of a missfire or possibly wrong jetting, it was 15 degrees cooler since last ride maybe that was the issue not sure myself, 190/195 jetting at about 1200ft above sea level. Any thoughts? thanks
Terry

 

here is a thing for the 686 kit just so you can double check yourself was it a backfire out of the carb or what was the sound like becuase it may be from downshifting at too high of rpms or the altitude...http://www.raptortranny.com/index.ph...d=20&Itemid=35

 

If you are using Mikuni 190-195 mains that seems too rich for your elevation to me.I run 175-180 in my 690 at sea level with LTE duals and it has been running that way for almost three years with no issues.

 

Check the plug for color. Unless you have monster porting, you are probably too rich.

 

I did end up checking the plug, but not the proper way and it did not look bad, I ordered 180 185 jets and see how that works. It started getting to the point if I was over 1/2 throttle it would start missing. Thanks,
Terry

 

let us know how you make out.

 

Well I just got done re jetting, went with 175/180 mikuni, while I had the plastics off I thought I would readjust the valves since they have not been done since the bore job, plus I was hearing a light tapping from the valve train. So I took it out for a quick ride and see how it worked (still heard the tapping), ran better then before but still up high in the rpm still felt like a miss, and then progressivly got worse (would start sooner in the rev range). So I am pretty much sick of the damn thing, but if anybody has any ideas... thanks.
Terry
p.s. I replaced the spark plug, just thought may as well.

 

go over to the bomb forum or ask driverdoyle as they are more familiar with drag racing and bigger bores and could porb steer you in the right direction

 

Hows your air filter [img]i/expressions/face-icon-small-shocked.gif[/img]

 

Funny you ask that, while I was changing the jets i did notice it looking awful dirty, But i didn't think it could cause such a failure, so I am picking up a filter recharge kit tomorrow and seeing what happens. Do you think that a dirty air filter could cause a sort to say miss like that?? Thanks again.
Terry