Hey guys, need some tech help. I'm running an ESR drag pipe and silencer, K&N filter, and a mild port job. It's been jetted with 165 main and 60 pilot. Going to pismo this weekend, so I added Boyesen carbon fiber reeds and took the airbox lid off. Ran it hard for a while, and it shut off on me a couple of times. I thought it might be running lean, got hot, and shut off. So I checked the plug, it was slightly brown, not the usual caramel brown. What size jets should I get? Thanks for the info.

87 TRX250r
83 ATC250r
81 ATC200

 

If i was you I would put the pilot back to where it was stock then move up on your main a bit.. buy 166 167 and 168 and see how it works out..

 

Why go back to stock pilot? When I'm just cruising at 1/2 or 1/4 throttle, it will sputter a bit. I'm gonna try a 158 main and 55/56 pilot. What about the clip? 3rd notch or 4th notch from the bottom? I'll try 3rd. Thanks for the help. I'm going to pismo with two Raptors, two piped 400ex's, and two stock YFZ's. Gottta put the two-stroke smack down!

 

SO all you did was put new reeds in and leave the lid off?? And now it is dying?? When does it die, at idle, after you let off - need some info - taking the lid off should not cuase it to run much differnt.

 

Yeah exactly adding some replacement reeds and taking the lid off should not make you have to change jetting. Also any color brown will do depending on that gas your running. Like dan said we need to know details

 

A 60 pilot is pretty fat, I'd go down to a 50 or 52 and move up possibly on the main to a 168 or 170. Pay attention to where your "stumble" is at, 1/4 throttle or 1/2 throttle. You may just need to adjust the needle position like you mentioned and that may fix your current stumble you are experiencing. And most importantly do plug chops at full throttle and check the color of the plug.

 

Actually you'd be surprised how much taking the air box lid off screws up your jetting. My 250R was jetted with the lid off and when I bought a new one from Honda and installed it my bike did the same thing. It would sputter at 1/2 throttle and bog at full.

 

i currently run stock cylinder with drag porting and the trx-11 pipe with the 39mm carb
pilot 42 and 175 main 2 clip on the needle

and mine runs very very well
perfect throttle

 

It was dying at idle after about 2 hours of running around. I changed the jets to a 168 main and 55 pilot. I noticed right away that the low end was not sputtering anymore, and it seemed faster getting to top speed. Did some plug chops and the plug was a mocha color, so I think I'm okay. Now, I'm thinking about increasing the displacement to 265. I can get the work done at ESR(about 8 miles from my house). Will this make much of a difference power-wise? I will eventually get the 310 kit, but I'm looking for more power now. 250R guys, give me some advice!


87 TRX250R
83 ATC250R
81 ATC200