heres the deal....
i put on an hmf slipon and it seemed to run pretty well....but with some backfiring when letting off throttle.
then i put on twinair filter......started hesitating and spluttering @ WOT from a dead stop.....then i jetted it 142f/145r and shimmed the needles .035.....still splutters and hesitates @ WOT from dead stop.....so thinking i was rich now i added napa snorkel.....and guess what?
it still splutters and hesitates @ WOT from dead stop......it runs GREAT from 1/4 throttle on thru WOT.....[img]i/expressions/face-icon-small-confused.gif[/img]
any and all help will be greatly appreciated as we have the best snow of the year right now and i wanna ride!!!!

 

Your needles are still too lean. Shim them out more.

Set the air screws doing the idle speed method. Get this right first.
Set the mains with plug tests. Run at 1/2 to full throttle for a minute, kill it before it slows down. read plugs. Set the mains second.

After you are sure those two are right, then mess with the needles.

Set the needles by how it runs. If it bogs when stabbibg the gas when hot, it is too rich. If it does a lot of coughing that only goes away when the engine is completely hot, it is too lean. You should notice it running worse when the engine is cold and improving a little if it really is lean.

When you do a fast stab, the needle has to enrichen first before the mains start to flow. This all happens quickly as the engine winds up. If the needle is only a little lean, then you still can run at steady 1/4 throttle, but when you stab the gas fast it will lean out and cough or hesitate.

Remember, lean makes a misfire. Almost like someone is turning it off.
Rich still runs but power is reduced. Almost seems like the engine is eating peanut butter.

 

thanks nyroc.....you've allways been a real source of help for all of us[img]i/expressions/face-icon-small-happy.gif[/img]
could you give me detail of this: setting the airscrews by the idle method?[img]i/expressions/face-icon-small-confused.gif[/img]
thanks for your reply[img]i/expressions/face-icon-small-wink.gif[/img]

 

air screw turning should rev motor at idle up or down. the idea is to get the motor to idle as fast as it can off the air screw. if idle is to high for you after this turn idle down with the idle screw. do one at a time (air screw).
two different screws air and idle on each carb.

 

Are your slides in your carbs moving freely?After shimming the needles its not hard to get the springs in wrong.[img]i/expressions/face-icon-small-confused.gif[/img]