Just picked up a YZ250 that was jetted for elevs of 2500 plus. Should be rich based on what I know, but when I road the bike at sea level if ran flat or boooowahed when I got on the pipe 1/3 to full. That would indicate it's jetted lean. How can a bike run fine at higher elevs jetted lean and not at sea level. I expected the bike to smoke and crack do to being rich. I haven't had time to go into it yet. Got home late last night, but I was thinking could the reeds hav cracks, or could it just need the clip moved down one notch. I have some work to do to get the bike to my liking and I'll run the choke test too.
Just wonder if anyone had any input, it's a 99 yz250 would be the same as the 2000 if your riding one of those. I ride everything from my home at 700' to racing in the high desert at 2500 to the mountains at 4500' I'd like to get it into that happy mid range jetting.
I'm in D37 souther california area.
Again the past ower said he had no problems at the races 2500-3000' or so and at sea lever it act lean. Just seems odd to me.
Guys I maybe mixed up on the lean vrs rich. High elev is low density so you do lean the jets. So I guess at low elev it would run flat. I'll pull the choke and if it runs better at the house than it is lean and should work better up high. I guess i can go to 50:1 or 60:1 from 40 or 32 to 1 and get it a bit rich would run better at 700-1200'. May wet foul the plug.
Thanks ed
Just wonder if anyone had any input, it's a 99 yz250 would be the same as the 2000 if your riding one of those. I ride everything from my home at 700' to racing in the high desert at 2500 to the mountains at 4500' I'd like to get it into that happy mid range jetting.
I'm in D37 souther california area.
Again the past ower said he had no problems at the races 2500-3000' or so and at sea lever it act lean. Just seems odd to me.
Guys I maybe mixed up on the lean vrs rich. High elev is low density so you do lean the jets. So I guess at low elev it would run flat. I'll pull the choke and if it runs better at the house than it is lean and should work better up high. I guess i can go to 50:1 or 60:1 from 40 or 32 to 1 and get it a bit rich would run better at 700-1200'. May wet foul the plug.
Thanks ed
Last edited: