MikeyG

Mod Ban
Nov 28, 2002
100
0
Ok, my and a bud of mine are messing with the jetting of his 88
RM250. We did a plug chop, got a slightly tan electrode with about a 2mm black ring at the bottom. Main seems pretty good. The lowered the clip one notch, and it cleared up the midrange pretty well. The only problem we had was with the pilot circuit. Once the airscrew was out about 3 turns, the bike revved really high. I assume the AS was off by a lot. So I know the bike needs a leaner pilot, but can I just leave the AS where it is and skip the pilot until I can get one? I sprayed starting fluid onto the AS too see if it was leaking and that was why the idle raised so quickly, but it wasnt leaking. The result of the jetting was great. Its got to be one of the best mods you can do. Bike now starts one kick, has instantaneous response off idle, and pulls smoothly instead of sputtering a bit like before. This bike used to foul plugs every other ride, so we are hoping this cures the problem. Is it ok to leave the AS at 3 turns out until I get a leaner pilot?
 

Superchief

Member
Feb 11, 2003
103
0
Originally posted by MikeyG
Ok, my and a bud of mine are messing with the jetting of his 88
RM250. We did a plug chop, got a slightly tan electrode with about a 2mm black ring at the bottom. Main seems pretty good. The lowered the clip one notch, and it cleared up the midrange pretty well. The only problem we had was with the pilot circuit. Once the airscrew was out about 3 turns, the bike revved really high. I assume the AS was off by a lot. So I know the bike needs a leaner pilot, but can I just leave the AS where it is and skip the pilot until I can get one? I sprayed starting fluid onto the AS too see if it was leaking and that was why the idle raised so quickly, but it wasnt leaking. The result of the jetting was great. Its got to be one of the best mods you can do. Bike now starts one kick, has instantaneous response off idle, and pulls smoothly instead of sputtering a bit like before. This bike used to foul plugs every other ride, so we are hoping this cures the problem. Is it ok to leave the AS at 3 turns out until I get a leaner pilot?

If the idle raises when you sprayed starting fluid near the air screw it is leaking. changes in idle when using the carb cleaner( starting fluid...whatever you have) method means there is a vacuum leak. I wouldn't think leaving the air screw 3 turns out is going to hurt anything significant except performance. i wouldn't ride it like that for a season, but for a day or two worth of riding i woudn't worry about it to much.
 
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