250-500cc WR300 jetting and tuning thread

The WR is my first smoker and the first time I've ever jetted anything. I had been riding FI bikes for a number of years. I would buy the kit again, especially since Hall's substituted leaner jets for me. So, 5 jets and a needle for $50 doesn't seem outrageous.

So it sounds like you've jetted your carb almost the same as mine with the exception of a fatter main. At 32.5, for my elevation, clearly I'm too rich in the pilot. I'm going back to 30 when I get my bike back. What did you do with the air screw? I know there are some PNW's out here who can hook you up with some recommendations.

Cool. Yes 50 bucks isn't bad at all. Unfortunately when I talked to Halls the kits are on back order from Husky. I'm on the list but am hopeful that I have my bike running better before that.

I know my jetting is in the ball park based on stuff I have read on here and some good advice I've gotten from other members so I am thinking that it might have everything to do with how I adjusted the pilot circuit.

I adjusted the fuel screw after I set the idle-trying my best to get the idle to smooth out, but I think that is where I need to start over and see if I can get a better baseline.

One word of warning for anyone out there don't ride off (even a short distance) without locking the idle nut back down. I went maybe a hundred yards with the nut just on there and not tight and the idle screw had nearly vibrated all the way out. Probably obvious but just thought I'd share.

So are you thinking keep the pilot at 30 and try the 3rd clip?
No shops in town here have a 32.5 apparently its kind of an off size.
I am going to order one but would like to get the bike running decently in the mean time.

I am thinking about going back to the stock jetting, keeping the needle raised and messing with the pilot circuit just to see where I need to go from there.

The bike idled and idles fine its just under load that I am getting the hesitation and what I assume is called blubbering.

I had a hard time tracking down a 32.5pj myself, but a local Honda/Kawi dealer had one in stock.

The 32.5 is the pilot for my bike at my ride spots, which should be of relatively similar temp, elevation and humidity levels as yours.

Read this jetting thread on TT: http://www.thumpertalk.com/forum/showthread.php?t=412662

It may not make much sense now, but once you begin going through the steps to get things dialed in it will start to come together.

My float height is set to 8mm using the method described in that thread. It was at approx. 6mm stock and the bike would puke fuel if sitting at a slight angle. FYI...Going to 8mm decreased the amount of fuel being held in the bowl at any given moment.

You said it acted the same with the stock jetting, correct? Did the problem get better or worse after changing the pilot and needle? 1/4 throttle is affected by both the pilot and needle as those circuits overlap at that throttle position, so either (or both) can be a contributing factor.

This diagram is a nice tool. It shows what circuits are in use at a particular throttle opening. Be sure to use throttle opening and not RPM to determine jetting.


I'd start my measuring float height. If it checks out then put the 35pj back in and see if it improves or not. If no change then its not the pilot and then change the needle back to stock and check for improvement.

I definitely think the 30 is too small and making the hesitation off-idle worse. My 300 did not like the 30 at all. My thoughts are that a bigger pilot combined with a richer needle may help. But you also need to make sure the air screw is right to get the pilot circuit dialed in.

Also, I'm assuming when you say 2nd clip, you mean second from the top so going to the 3rd will be one step richer (raises the needle).

Okay, I'll check the float height tonight.
Change if need to and see how it runs.
If no improvement back to stock pilot(35).
If still no improvement back to stock on the needle (3rd clip).
My main will still be one size leaner and if need to I'll bring that back to stock too.

I feel like maybe I jumped into too many changes at once and needed to go step by step instead. I know patience, patience...Its just that its such a cool bike and I'm ready for it too be running right.

I had to order the 32.5 pj since there are none in town.

thanks for the help and the patience.

G-A-Y Needle

Just installed needle from power up kit, middle clip, 460 main, stock pilot, air screw out 2 1/4 turns. All i can say is wow , this thing rips from right off idle to going way faster than needed. Jetting seems really close.Also installed 51 in the back with 13 in front , gearing seeems really good too.

So yesterday and today were my first days to ride my bike with the 32.5 pilot jet. Just ran it at a buddies track and some local hill climbs but it was still a pretty good test. Bike is running very well. No bog, no miss and just flat rips. Thanks for everyone's input on this.

I am hoping to get some real single track time in this up coming weekend. Didn't want to mess with elk hunters too much this weekend but Sunday next week they should mostly be gone...

Snow is coming so time is running out.

I have a PC pipe on my 07 WR250 with the stock Husky spark arrestor. I bought it like this, the silencer pipe might have been cut to fit, but it works and no spooge leaks.

A new pipe for a 2T is always a joyous time ...

I always gotta say the C2 racing pipe I put on my 02 CR250 was one bad a$$ pipe ... Whatever the power curve was on paper from the PC pipe it had on it, this pipe totally superseded that entire line ... The beast was released!