All 2st Jetting Chat - Need Help? Post Your Questions Here

The "racehead is good, but when i get tired and start to get slightly unfocused i feel that the 300 is almost too much as it is standard=). I feel that it gives a too abrupt powerdelivery with the racehead at those times.

Johnny

Thanks for the heads up about the reed assy, My plug was still a dry coffie brown color after when I pulled it out after the 2nd seizure. There is a fair chance it leaned out through that reed assy. I'll check mine. Cheers

I'll grab a couple and throw them on. Its gotta be something funny like an air leak.

What year Honda?

The last gen CR's. 2002 - 2007.
They use the same reed cage and gaskets as the 250/300 Husky's.

Hello Dartyppyt, I saw your post on the rm needle and how you bought them all and settled on one. I read other posts praising the rm needle but your post flicked the switch on for me. I'm thinking my 144 may need leaner needles, the 63 or 64.I thought the slide affects the mixture at smaller throttle openings. Does the slide affect the entire range? At the moment it is very smooth and responsive at low R's. It really is. On another post I think by Krieg, he mentioned his 144 is rich in the middle with the 62 and 5 slide. The next step is to get the kx slide and leaner needles, looks like. If that doesn't do it I can cut the 4 slide to a 5.5 or leaner, after I see what a 5 slide looks like. Ran a 440 main today at 85- 90 degrees and 3K feet and picked up some more revs. Forgot to state for the jetting database thread that I have Walt's white and blue regulator springs installed, 7200 -7800 range. Float level at 8mm. Anybody know what opening the PV earlier does to the fuel curve? Can you force a lean condition with earlier opening as the mixture goes out of the cylinder from increased exhaust duration. Or does it get richer from increased flow. Dartyppyt can you tell much of a difference between a 62 and 63 with everything else the same?

Pm sent, thanks dartyppyt.

I stole this from the GasGas forum to share with my Husky brothers and sisters.

great diagram, thanks lankydoug! helpful addition to the jetting files

I got tired of dealing with the cheapo phillips head screws in my Mikuni carb so I went to an industrial fastener place and matched the thread and size to an allen headed screw that was of better quality. Here's the deal; in order to buy from this place I had to buy a box of 100 of each item. I only needed two of the top plate screws and 3 bowl screws so I now have enough extras to make 30 kits if anyone is interested. I will calculate the cheapest shipping and mail a set (5 screws) to the first 30 people that PM me.

I haven't been 100% settled on my Mikuni TMX jetting for my 2009 WR250 so this weekend I got around to do some more testing and I thought I'd share what I learned (I revised my current settings in the jetting database post #53):

1. Go out with your tools and jets and keep making changes, one at a time to really figure out exactly what is happening. And go to a place where you can do a hard 15-20 minute trail ride to evaluate the changes. In the past I have been too impatient and would change a thing or two to make it better and then go ride. With limited time it was too easy to say - it's working pretty good, I just want to go ride. When subsequent rides are sometime apart it is hard to remember just how it rode before when you change something and go out next time, even if you do take notes.

2. The Mikuni settings are way too rich from my experience, especially at 6,500 ft elevation. I am now using a 27.5 Pilot, 2 out on AS, GAY Needle in 3rd, 360 Main. I found I was compensating with needle changes, when it really needed a leaner pilot. I was using 30P, needle in 2nd and the power was strong but kind of twitchy like a high strung 125 - I could tell it was on the lean side but it was still spooging like crazy. I went to the 27.5 pilot and the spooge stopped but it still felt lean over 1/4 throttle. Then I raised the needle to the 3rd clip and the power smoothed out and was stronger than ever. I ride alot of tight singletrack in second gear and now it pulls hard right off the bottom when coming out of a corner with minimal clutchwork. Very impressive.

3. Check your powervalve. I finally did and it was off. I set it at 50.5 mm. It was at about 48 mm, which I believe is the motocross setting. Lowering it definitely increased low end power. And I think it made the pilot circuit even richer.

4. You can get rid of spooge with proper jetting. On a 15 minute trail ride with the 30P and needle in 2nd I had spooge running 2/3 of the way down the silencer. With the 27.5 pilot and the needle raised to the 3rd clip I had over 2 hours of ride time yesterday and there was only a little spooge on the endcap and it ran better than ever.

5. The circuits overlap alot with the Mikuni. It's easy to be mislead into adjusting the wrong circuit. After switching to the 27.5 P with needle still in the second clip I went on a high rpm run and the power fell off at the high end like it did last spring when I was trying to get the main figured out - I was thinking WTF?. After raising the needle to the 3rd clip it pulled strong right to the top like it did before. Confusing to me, but is seems that the needle has an effect at wide open.

To sum it up, I am absolutely thrilled with how this bike is running now. I really don't think the Mikuni is as bad as some think. I just think they give us way too rich settings to start with and the recommendations in the service manual for various conditions and elevations are way off. For me they weren't even close as a starting point, and I was afraid to lean it out. I would be very curious to know if the euro race teams are using the Mikuni and what kind of jetting they are using.

utopia, I have been thinking of going to a 30 pilot and raising my needle 1/2 step to the 3rd notch. What you have posted reinforces my idea. Thanks, I think I'll try it. We both went in similar directions but you are at a higher altitude and went a little leaner/further.

Can't hurt to try it. At your elevation it may be right on. I may even try a 25 next summer but with temperatures getting cooler I'll leave it for now.

+1 Utopia for taking the necessary time to test and learn this whole wonderful world of jetting.....it's not really that hard is it

Not that hard and actually it was fun. I'm ready to do another one.

These are from the shop manual thought this could help

Got the screws today they fit perfect thanks :0)

2010 WR300
I pulled it apart today to get it jetted properly. My elevation is 5000ft+ average temp is 18C (high 60s), and it's dry here. I put in a 40 pilot, smooth tapered needle 3rd clip, and a 380 main. After initial trial, it doesn't start well, and will only idle when choked. Where do I go from here? Thanks in advance.

Joe, This was on another thread.

Yep, that's what I used. I just can't figure why it won't idle unless choked. And where's the info on the needle?

Thanks