Quote:
Originally Posted by clakmurrick
When you said "which is same as stock," did you think that I left the pilot jet the stock size? I replaced the main jet with a 117.5 and the pilot jet with a 40. I replaced what I believe is the idle jet with a new OEM spec one. That should still be the same size. Sorry for the late response. I'm coming back to these threads now. The bike ran a lot better when it was cold, but now that it's hot again, it needs to be revved to 6k RPM to get up and go otherwise it bogs out. I want to keep trying with my setup and see if I can be successful, otherwise I might have to just buy an oem airbox and put the jets back to stock. I also need some springs for the slides since I cut those. I sure am learning a ton!  |
OK - from what you are telling us it's running significantly rich.
You don't need 40 Pilot Jets, but you may be able to use them if you can turn the Idle Mixture Screws in enough to get the proper mixture. You may be around 1 to 1.5 turns out with the larger Pilot Jets.
117.5 Main Jet is way rich. We ran pods and a leaky stock exhaust with 108s I believe - and it pulled strong all the way. Not a big fan of carb kits with larger everything.
Not sure who suggested cutting springs and slides, but that's not a typical carb mod from what I've seen.
As you can see, changing a bunch of stuff based on someone's suggestions can create all sorts of problems and most of the time doesn't really gain you any usable power.
A properly tuned 250 with the stock airbox will give you nice crisp low and mid-range performance. Opening things up usually flattens that out, and sometimes doesn't gain anything anywhere.
Proper carb tuning is critical. They are pretty close as is, but require precise adjustment of the idle mixture and maybe a shim or 2 on the needles to run much better. The Main Jets are usually overly rich, and more power can be gained by replacing them with the optimum size depending on other factors.
Final step is to make sure the carbs are synced properly.