Carb update- rejet

[ruffrider]

I ordered 2 sets of new mains from MikesXS, 140's and 142.5's. Installed the 140's yesterday in about 2 hours to r&r. I'm getting faster at it any way! Draining the gas takes awhile but my petcocks still leak a llitle on off so no other choice. She started right up and idled well after choked for 30 sec. Went for about 30 min. ride. What a difference! the mid range power increased and it pulls better at WOT. She still stumbles barely between 6.5 k and 8.5k revs but only about half as much as before. The plugs are coloring up some to but still look a little on the lean side. ( pretty white-only slightly tan)I think I'm almost there getting it dialed in. I'm thinking of just leaving it alone but I'm still lusting after that last bit of gittyup. Any suggestions? Should I try the 142.5 mains? Or raise needles one notch? Maybe it needs a K+N filter too. I think I'll burn up this tank first. Sure is fun to ride. Alot more nimble than the Wing and stops quicker too.



Any suggestions? Should I try the 142.5 mains? Or raise needles one notch?

[DiverRay]

If you have stock exhaust, the 140 should be fine. You can tweak the float level about 1mm up and down to increase or decrease the fuel flow at all ranges. 1mm closer to the carb body, and you are looking at more fuel flow at all RPM's, 1mm the other way, and it will lean out just slightly.
HTH

[Bob Falter]

I’d go with the bigger main jets. If raising the needles one notch makes as much difference as lowering them by one notch, raising them may be too much. I just lowered mine one notch and it made a lot of difference over the entire range, going from a slightly rich condition to a too lean condition and a bad WOT miss/sputter at over 6,500 rpm.
See this thread http://www.xs11.com/forum/showthread...threadid=19798

Bob

[ruffrider]

Thanks one and all

This forum is great. We can compare our mods and results to greater understand these finicky beasts. Bob, I experienced the same thing while playing with the needle height adj. It makes to big of a change for what the top end is lacking. And Driveray, I'm already at 22mm with the plastic floats and I also did the clear tube check which showed the bowls full up to the washer in the bowl screws. Don't know if I can take it much higher and not overflow. When I get around to it I'll try the 142.5 mains. Thanks guys.

[IMG][/IMG]

[ruffrider]

Mystery solved

I thought I'd try something before changing to the 142.5 main jets. I'd been reading about drilling out the stock air box so first went for a ride with out filter and lower half of box. Wowsers viva la difference! Now she'll pull hard all the way to redline with out a stumble. So I went ahead and drilled 6 .5" holes in the air box (inside where the filter sits..... I did a search first on posts, Thank God). Put air box back on, after cleaning Uni type foam filter up good.Viola!! it runs like a champ now. Managed to get speed up to 100 before running out of road. I'm sure it'll go to 120 but don't want to try it. Plenty fast now.

[Bob Falter]

That’s great that you got your bike running good. It must have been running rich and adding air solved the problem. It just makes me wonder why your plugs weren’t showing a rich condition. I guess this plug theory is like a lot of theories, great in theory but no so great in reality.

Bob