throttle response

[muggzy]

I just re-read your first post and your specs in your sig. You're at sea-level, I'm at 900ft, we have VERY similar set-ups where it matters for jetting. Put 27.5 pilots in there, needle clip on pos. 4 and leave the 280s where they are for now. Start with the bleeder screws at 1.5T and simply try tweaking the bleeders equally 1/8th of a turn at a time and until any off idle bog goes away. Then give them another 1/8th turn in the same direction for good measure. If you have to go more than 1 full turn open, move the clip back to position 3. More than a full turn closed, go to #30 pilots. Either way, start over with the bleeders at 1.5 T.

 

Remember the overlap? If your needle clips ended up in a leaner position than your original, you'll have to go richer one size on your mains to keep that coffee brown, If the clips went richer, you may want to go down a size. Once you've got that done, go back and re-do a plug-chop to make sure your high end is still where it should be. Lmk how it works for you.

 

Oh! All this assumes your reeds are in decent shape. They supposedly don't affect jetting too much but they do have some effect and they very definitely affect throttle response.

Edited November 21, 2010 by muggzy

[shoopie]

Alright guys. I made a mistake when I first started messing with my needles. I Leaned it out 2 clips instead of richening it (which is what it needed). I thought the problem was that it was too rich when it was too lean. I dropped the clip down to the fifth position and it is a lot better now. Barely any bog. Top end is great. Low end could be a little cleaner but its a lot better than it was. I am going to get some bigger pilots and mess with the screws to get it perfect. I also started running avgas in it which is 100 octane low lead. Instead of the VP c12 108 I had in it before. It made the whole powerband a lot smoother but in the low revs its a little choppy.

[AKheathen]

i cannot say that the needle is going to affect what main you need in there.....it would have to be a really long, fat needle to do so...maybe like a 16penny nail. i got a set of 30's once that had some lean ass needles...it actually did effect the wot, and not in a good way. p.o. tried to fix it by spreading the needle jet horn, and running a real small air jet to get it rich enough......if it's running decent from 1/2 throttle to wot, then make sure it's spot on at wot.......a plug chop is a good way to verify. that is the only main size you should be running, unless weather conditions, or elevation and/or mods change. then, play with the needles untill it runs good, crisp, and clean from about 1/4 throttle and up...... after that, play with the airscrews, small adjustments at a time, to get it to run the best. if it doesn't clean up well, then get it up to operating temp, and adjust the airscrews small amounts, until it reaches the highest idle. if it keeps idling up past 2.5, then it needs a smaller pilot, if it wants to go less than 1/2 turn from seated, then it needs a bigger one. if it doesn't seem to make a difference at all, then pop the choke 1/2 click and see if it gets better or worse, to see which way to go. remember- all adjustments should be made to an engine at operating temp, not cool....as they will be very different........once you get in the range with the pilot, get it warmed up on a good setting to operating temp, then get it to idle the highest with the mixture, bring the idle back down with the idle screws, and do it again. then, turn them in another 1/8 turn and try that.......it's normally pretty close.

[sleeper06]

Thanks shoopie there is a fine line between lean bog and rich I have messed with and tuned so many diffrent bikes i have them in a rolodex of cards.I pulled your card should be close,I forgot what your compression was but running race fuel if its not warented will hurt performance the fuel burns too slow