Quick jetting question???

Budget_Blaster

New Member
Dec 25, 2009
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Illinois
Ok finally got around to dialing the carb in on my 240bbk and ive got a couple questions...

Ok first question is i had three total stock jet needles two were identical brass y144 and then one not marked made of aluminum with 6 positions for the clip which i used i belive it came with the rebuild kit i bought a while back.Now my question is these all were physically the same demensions and taper the only difference was that the y144's had 5 clip positions this aluminum one had 6 so i used it and put it on the 4th setting from the bottom up is this ok and has anyone ever seen a jet needle for the stock carb with 6 positions?This helped it tremendously and made it snappy as hell plug chop hasnt been done didnt have time but ass dyno says its close now combined with the 340 main.


My second question is im running a 32.5 pilot jet and set the the idle after fully warmed up to the factory setting or as close as i could my tach says 1675-1750rpm.The a/f screw is only 1/4 turns out and its running and idling great but the info ive seen says if its more than 2.5 turns out you need a smaller pilot and if its less than 1/2 that you need a larger pilot is this setting ok if its idling ok and running good?Or do i need to step up immediately and if so what size?


Third question is before i left tonight i fired it up real quick and it idled kinda high while cold with out the choke engaged to about 2600rpm it was cool out at about 50 degrees will this idle down as it warms up or is it not adjusted properly?I didnt have time to let it warm up i just fired it up to see how easy it would start cold on a couple kicks since before this it was a biotch to start if it had sat for a few days.I did pull the choke when i started it cold and the idle dropped down but kinda wanted to stall am i lean?

Sorry so long guys but id rather not have to do another top end.But the quick 20 min cruise i went on was night and day and its hauling ass now just the idle and pilots got me worried.Thanks
 
i'd bump that pilot to a 35, should cure that 1/2 turn airscrew and possibly the high idle ???
was it leakdown tested ????
 
No but its been together and running like a champ and ive not even removed the carb when i swapped jet needles.

I highly doubt with 11hrs on it running fine and the only change being a jet needle its leaking.

So cold or hot it should idle the same rpm?
 
it should idle close to the same without the choke on, but will prolly be lower and hesitant when cold

was it ever leakdown tested, airleaks can develop over time, idling high when cold, then simmering down after warm up could be a sign of that, things swellup and seal as they heat/expand