250r jetting

[jsnhntr250R]

i just bought a 86 250r. the motor was stock as far as i know. i put a ep hand blown pipe and boyeson power reeds, ever since then it has not ran right. the main jet was a 140 with the clip in the the top position, when i kick it it starts but any throddle and it seems to flood and die the plug is wet and black. so i dropped the main jet to 135 and moved the clip down one, its now worse it starts but only runs for 3-5 secs before it dies. then i have to dry the plug before it starts again. the smoke is white and sometimes backfires. if you can't tell already this is the first time i have jetted a 2 stroke and now i am lost please help with any info


air box lid is off and a foam filter

[250R-Dee]

You need to check your float level. Is it 16mm? Mainjet changes will not resolve problems associated with starting. Did you do a compression test on the motor? Are you using a NEW plug? Do you have an airbox?


Stock jetteing for an 86' R is below.

needle clip : 4th groove from the top
slow jet: 48
main jet: 150

[jsnhntr250R]

the air box lid is off, what should the compression be at? if i go back to stock jetting should it be lean or rich with the mods i have done? the plug was both new and used i have many plugs
i had it running for the first 2 days then i washed it and thats when it started. i thought that the water might have gotten into the motor somehow but it should be out by now. when i put in the reeds and pipe i also cut the gas to 60:1, cleaned the filter and reoiled it. the directions for the reeds said it would run rich for a while. thats why i went to a smaller jet after 3 runs. man this thing ripped on those 3 runs though:devil: i have a 1/2 mile motox track and need to get on it again before the withdrawls start kickin' again.

[ESR350r]

compression on a 2 stroke needs to be around 120 to even run, anything more then that is fine. The new pipe should not have made the quad stop running. When I put a new pipe on my R I threw it on and started riding with out rejetting. I can also remove my air box lid and put it back on with out seeing any changes in how it runs, and it still seems to be at the right jetting. You obviously have a fuel delivery problem so back start back tracking. I would suggest putting the old reeds back on and see what that will do. Your clip adjustments should not matter because that is 3/4 throttle and up. You said you dropped a jet size and it was worse so go the other way and see what happens. I would start by putting the old reeds on and trying it, then maybe the pipe. and if it still acts the same then you know for sure it is the carb. It could be something is wrong with the carb itself or the jetting. it is just a matter of eliminating options. Welcome to the world of 2 strokes. just narrow down the possibilities. If you narrow it down to the carb and you still cannot get the jetting right or find a problem with the carb find someone who has a good one and try it.