Sputtering on the top end

[01shee]

Ok I didn't want to post this because I know i can figure it out. Just to darn cold out to be messing around with things. My 330 is sputtering on the top end. Bumped my main up to a 185 from a 180 for the winter. Both the 180 and 185 were sputtering. It has a cr250 ignition. Messed with the jetting and still a sputter. What am i missing. I check spark and its strong. Also taking quite a few kicks to get it started. Help would be great.

[8686]

What is your plug gapped at? Did you try a new plug?

[01shee]

new plug gapped at .18

[1promodfan]

Have you tried coming down to maybe a 178 or 175??

[01shee]

Going to pull the plastics tomorrow and check all the wiring. And going to drop the main some more. This is a different motor then what i was running in the summer. Same size motor. Same carb. In the summer I ran a 178 in that motor. I just figured that would be lean in the winter. But i guess every motor is different and require different jetting.

[01shee]

Bumped my pilot up because it was lean. Bumped the main down to a 180. Then did a full throttle run. Checked the plug its lean. The wiring is all good. The plug cap doesn't seem to be clicking on the plug. I prayed the little clip out more in the boot. Still not very snug.

[latheboy]

For what its worth....I jetted both of my R's up 2 sizes on the main for the cold weather. They are both real close now...

[LONG-ROD]

check to see if you can see some wire when you pull the boot off. might need to be stripped.

[cleanone]

Check your reeds. Could be a problem.

[adamson350r]

Brothers R was doing the same thing. Fixed it by changing reeds but after wards I had to play will the fuel mixture screw. Took half a turn.

[250r__Ice]

On my 330r I had to go down to a 175 main to get the miss or sputtering out on top end. I thought it might be to lean but the plug looks good. Its a paper bag brown color. Was running a 185-180-178 but it took a 175 to fix it. My elevation is 1600 feet.

[adamson350r]

Glad you got your machine running right. That's awesome.

[troybilt]

running into the same problem with mine, switched carbs from a 38A/S to a 35A/S and now having sputtering problems on top end. 158 main now, switched to 162, 168, 178, and still have the problems, I don't have a smaller jet with me. Do I need to go down to 155? Other than that, its running well. I know these 35 A/S can be a pain to get dialed in. Any help would be appreciated. Needle on middle clip, I think it has a 45 or 48 pilo if I remember correctly, when I put itn on.

0.010 Bore, FMF SST, 185 psi comp, Rad Valve with spacer...

Thanks!
T

[250r__Ice]

When it got hot last summer I had to go down another size. Im at a 172 main now. It runs great with no sputter. Before when it did miss it would do it right at top end full throttle. When I had my ESR 310 kit I was running a 190 main. But when I got my 330 kit I figured it would be about the same. Not so. I got a hand full of jets and started doing wide open plug chops. I started with a 195 main and kept going down a size at time until the miss was gone. It was winter when I did this and it quit the miss with a 175, but when summer came I has to drop to a 172. So far its been doing great.

[01shee]

ice what carb are you running? I got the sputter out this winter but now its back. I have a 180 in it know. Going to order a 178 175 see if that helps any. I put a new plug boot on because the old one was wore out. I think my coil might need replaced because i cut it back as far as i could and there were only a few wires showing. I have a 38mm a/s

[250r__Ice]

Im running a 38 a/s also. 2nd clip from the top. 50 pilot 2 turns out. cr rad and ignition. Not sure about the needle, it is the one that came with the carb, cant remember right off hand. Mine did good until it got hot during the summer and the humidity went up. Got just a very slight miss at top end. I droped a size and it cleared up. The elevation here 1600 ft. Where we ride in the mountains it can range from about 900ft to 2800ft but it dosent seem to cause any problems.