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hi can any help , i have removed ai, top snorkel gone .uni filter in, removed 1st and 2nd baffle drilled 4 holes in third , rejetted to 125 mains turned out screws 3 , 31/2 4 and 4 1/2 getting good idle but will not rev past 6 thou and no guts pulling in first any suggestions . also chewed up one pilot mixture screw got two replacments but were d shape mines o2 and just crosshead so i altered these to screwheads but does anyone know if they are identical they looked it when i had them out but might be the tip thanks kevin

Sounds like you might need 130, maybe even 135 main jets.
As far as I know, the head was the only thing they changed in the newer idle screw. When you swap them, be careful to collect the spring, washer and O ring that are in there.

Check everywhere around and on the carbs for vacuum leaks.

did you have the tops of the carbs off?

Every time my bike has been very lean it's done the same thing and rejetting richer fixes that. And after what you did you definatly need to add a shim or 2 and up the mains. And being so lean that is doing that means it's also lean enough to do damage. Once you rejett it'll run like a crazed cat too.

Some are of the mind that max is 3 1/2 turns out, then go to the next size pilot. Pilots and screws control idle mixture (throttle closed). Popping on decelleration and hard starting indicate too lean pilots/turns. Getting pilots right helps throttle response. I installed TBS needles and 1 shim last weekend, didn't run that great.
Removed the shim, ran great. I have a similar setup, removed last 2 baffles and pulled snorkle.

Mine had a flat spot like that also. Bigger jets corrected it ...

put the original 120s back found i chewed up o ring on both sides manifold to head replaced and still running rich but better drilled two 1 inch diam holes in bottom of airbox refitted uni and shes flying now really feel it in midrange slight poppin on decel cant come much further out on airsrews now

Jet swapping!? I'm the jet swapping king. When I put my Epcos on with the recommended 130 mains, I had the same problem of starving once getting up into the RPM range. AI was gone, UNI filter, holes drilled in filter and box. I tried EVERYTHING thanks mostly to those on this board to fix the problem, i.e., Pingle petcock, checking the little filter in the fuel line, etc. Well, I went to 132s, 135s, 138s, 145s, and then 155s to get rid of it. I now run 160s with no problems and she hauls A--. And, in 5 more days I get to pick 'er up after the Weisco BB kit!

Roy, let us know if you have to rejet leaner after installing your big bore kit.

(Bigger displacement means greater pressure drop through the carbs, hence a possible need for smaller jets, as the carb is not self-regulating like some fuel injection with a mass airflow sensor.)

Dale, the difference between your carb jetting and Roy's might be in the exhaust system. If his is freer flowing (read: louder! <chuckle>) that certainly could make the diff.

Density altitude could be another factor. If Roy's bike is "seeing" lower numbers than your bike, it would need to be at least a bit richer.

Yet another consideration is ignition. If Roy has Nology coils and wires, this would let him run slightly richer, too.

One more idea: bigger cams reduce signal to the carbs, so you usually need to rejet richer on just that basis.

It all adds up in the end.

I have thunderbike pipes which i *think* are probablt as open as any other unless of course they removed thier baffles. 130's made no difference in my bike over the stock 120's except in the bike's demeaner. In other words, they made it feel a little smoother and the sound changed slightly. But no poer diff. While needle changes has netted me significany increase in power. So that led me to thyink maybe i need richer mains. But i was hoping someone would be able to tell me how high i likely could go before seeing negitive resluts. if he went to 160's w/o an airbox removal kit i just cant help but think i should be able to go to at least 140's and that maybe then i WOULD see an increase in wot situations. But i hate buying jets w/o knowing because they get expensive with shipping if they end up being put on the shelf.

Check with Bella Course. I think they'll sell ya a whole set of jets for the price of one set and you get to experiment wtih them until you get the right ones and then send the rest back.