Scott Summers Jetting

[Sage]

Hi All

Have any of you used the suggested jetting that's in Scott Summers 10 tips for XR 600's, 68 pilot, 155 main and mixture screw 2 1/2 turns out, with free flow exhaust and free flow filter.

Just wondering if it works well, also no mention of the needle postion, is this just left as std.

[todd5774]

HMMM.

Im running 68pilot, 170main, needle standard and airscrew 2 1/4 turns out. At sea level.

Bike has a twinair filter and a fmf powercore pipe with the freeflow headers.

power strong throughout the rev range, still get the slight stumble off idle throttle though although i have been told you cant tune that out, need a pumper carb to get rid of that.

However my bike after 8months of running good with these settings has developed a 'hunting' at steady throttle openings if i give it some more it disappears, when i get time will tear into the carb to see if i have a problem.

[Sage]

Hi Todd.

Thanks for the reply, just trying to get as much info as I can before I start, nothing worse than changing things and getting on the trail and find you have problems, what year is your bike, mine is a 1996.

I supose I will have to give it a go and see how it goes.

[todd5774]

mines a 93.

Do your changes then take the standard jets with you when you ride as it's no bother to tilt the carb over and change your jets over on the side of the trail.

[Sage]

Hi Todd.

Well there in, so I will have to wait to latter to see how it goes, mind the SS jetting is still leaner than yours , but richer than std, so shouldn't be to much of a problem, I hope !! Mind it did run well on std jetting, but a bit lean I would of thought.

The free flo header on your, what are your thoughts, are they worth the money, I have ported out my std header, what ID are on your headers? Looked at some FMF headers, haven't got a spare £199 at the momment.

[ogri]

hi mate.SS jetting tips may be of use to you if you are using the bike at the altitude and temperature setting similar to the one's expressed in the article.once set up,a carb in the uk is usually good uk wide because we don't have the change in altitude and temperature that they do in the states.my jetting, set up in s.wales has worked everywhere in the uk,with perhaps a little tweak of the fuel screw to accomodate extreme temps during the winter.talking about a xr400 and drz400.fully expect my xr650 to be the same.

[Sage]

Hi Ogri.

Thanks for the reply, gave it a go last night started well, ticked over well, ran it untill it got hot, fired straight back up, did have time for a good ride, I will give it a plug chop then, fingers crossed!!