cheetah cub 35mm carb jetting help!

[lansingbird]

I don't post alot but read alot of these forums. I know somebody here can help so here goes. I have stock bore cubs, shearer in frames,35mm pwks,vforce 3,18cc domes with 180psi,vp 110, +5 timing and live in ks. I just got these carbs and have 162main 50pilot cel needles on middle clip. It bogs a ton and have to down shift alot to keep rpms up. adjusting the air screw doesn't make much difference. I was at a 55 pilot and 170 main. seems like it has no low or midrange. when It hits power band it screams. maybe higher octgane fuel? different needle?If you can help please chime in I can't find anyone with a similar setup. Thanks.

[RadarRacing]

I don't know what your plugs look like and you haven't mentioned pulling a plug or chopping. Take this from a guy that likes cubs , they are not known for having torque down low. They are designed to run very well at 8,000 rpms and up. Gearing can help as well as tuning the main as well as the needle but unless you are tuning off the plugs we can't help ya much honestly.

[okbeast]

We've run 35 pwks on stock stroke and 4mil cubs with jetting at 155 main 48 pilot in all kinds of weather. Ran great on all the bikes.

[lansingbird]

We've run 35 pwks on stock stroke and 4mil cubs with jetting at 155 main 48 pilot in all kinds of weather. Ran great on all the bikes.

Ya thats kinda the way I was thinking. I'm a little rich. Plugs were a tad wet on the threads and a little dark on the electrode but not wet there or real black.

[lansingbird]

I don't know what your plugs look like and you haven't mentioned pulling a plug or chopping. Take this from a guy that likes cubs , they are not known for having torque down low. They are designed to run very well at 8,000 rpms and up. Gearing can help as well as tuning the main as well as the needle but unless you are tuning off the plugs we can't help ya much honestly.

I did a plug check wot and had a little darker than tan but not much. They were a tad wet on the thread and I mean a tad but not on the electrode. I don't expect alot on bottom end but It has nothing. 13-42 on the gearing. Are you running similar setup?

[bansheeboy44]

I did a plug check wot and had a little darker than tan but not much. They were a tad wet on the thread and I mean a tad but not on the electrode. I don't expect alot on bottom end but It has nothing. 13-42 on the gearing. Are you running similar setup?

 

Prior to mine being drag ported w/ the same set up, except with 20cc domes, mine was dyno tuned and it ended up w/ a 168 main. It's been a while so I don't remember the pilot, but it does have the 55's in it now so probably a tad leaner then. Also, it previously had the CEL needle in the middle spot.

 

I'm in Phoenix at about 1100 elevation and it was about 85 the day they tuned it.

[RadarRacing]

I had a 392 Cub with 35s and ended up tuning down to a 148 main on the dyno and it was 11hp stronger than when I had 155s in it. If your plugs are brown as well as wet then you are extremely rich more than likely. Chop a plug don't look at it till you cut the threads off and see where it is.

[lansingbird]

I had a 392 Cub with 35s and ended up tuning down to a 148 main on the dyno and it was 11hp stronger than when I had 155s in it. If your plugs are brown as well as wet then you are extremely rich more than likely. Chop a plug don't look at it till you cut the threads off and see where it is.

I am at plus 5 timing wondering what you guys were running for timing ?

[lansingbird]

We've run 35 pwks on stock stroke and 4mil cubs with jetting at 155 main 48 pilot in all kinds of weather. Ran great on all the bikes.

I changed the main jet to a 155 and improved a lot . I still need to get the 48 pilot which I think I'm still rich on with the 50 .I was wondering what timing you were running at. you guys have been a huge help already thanks for all your replies .

[okbeast]

I think I was at +6 timing