SQUIRLEYMOFO
Member
- Jun 11, 2002
- 310
- 0
SQUIRLEYMOFO said:I did a search and found a lot of people switching to the Keihin from the 2000 and 2001. Most of the posts were a couple of years old. Has anyone had sucess jetting the Mikuni are is the "hot" setup still the older carb?
rcpilot_971 said:I just finished putting a pwk on my o2 cr250 like 10min ago kind of a pain to put on have not got to ride it yet I hope it runs good with the stock jetting I would hate to have to pull it off again had to take the sub frame off and then had to take the air box off the sub frame still would not go right on had to work it a little
Tim
mylesc said:rcpilot_971,
To rejet your carb, you don't need to pull it off again. If you need to change out the main or the pilot jets, disconnect the fuel line and remove the slide/top cap assembly. Drain the float bowl. Loosen the clamps and rotate the carb until you have access to the float bowl. It's a bit tight on the aluminum framed CR's but once you do it, it's not so bad.
mx547 said:i made the switch. i didn't have any trouble getting it in there and didn't have to take anything off. i'm running stock jetting and its close. its nice to have that problem out of the way. get the keihin and spend your time riding instead of messing with carbs.
the 2001 had the mikuni.
mylesc said:rcpilot_971,
To rejet your carb, you don't need to pull it off again. If you need to change out the main or the pilot jets, disconnect the fuel line and remove the slide/top cap assembly. Drain the float bowl. Loosen the clamps and rotate the carb until you have access to the float bowl. It's a bit tight on the aluminum framed CR's but once you do it, it's not so bad.
What kind of jetting are you running now?mtk said:You don't even need to do all that, at least for main jet changes. Skip removing the fuel line and simply turn off the petcock. Stuff a rag under the float bowl and then remove the large hex plug in the middle of the float bowl, draining the bowl and exposing the main jet. Remove the main jet with a 6mm wrench and reverse the process.
Slow jet changes require carb removal, but I found that to be relatively simple as well. Unbolt the silencer mounting bolts (so you don't have to mess with the pipe/subframe connection), loosen the airboot clamp, and then unbolt the three subframe mounting bolts. Remove the subframe, with airbox attached, and then you can pull the carb out, after you remove the top of the carb and the slide.
I've been much happier with the PWK than with the stock Mikuni on my 2002.
As for jetting, my 2002 has been Mo Betta ported by Eric Gorr, so that changes things a bit. But with that said, I'm running WAY leaner jets in my 2002 CR250 with the PWK than that same carb used on my 2000 CR250 engine.
I just changed out my slow jet a few days ago by removing the chaing guard, loosening the carb clamps and rotating the bottom out to the side; I didn't even remove the slide. Once you rotate the bottom out, remove the four bowl screws, remove the bowl and there you go. About a 15 minute job.mtk said:Slow jet changes require carb removal, but I found that to be relatively simple as well. Unbolt the silencer mounting bolts (so you don't have to mess with the pipe/subframe connection), loosen the airboot clamp, and then unbolt the three subframe mounting bolts. Remove the subframe, with airbox attached, and then you can pull the carb out, after you remove the top of the carb and the slide.
Glad to hear that the porting is running well. It has been mentioned that a jetting reduction will probably be required after porting.mtk said:As for jetting and performance, I'm running a 162 main jet, 38 slow jet, air screw ~1.5 turns, and an R1368NS (CR500) needle on the 3rd clip in the bike right now.
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