33 smoothbore help jetting please

Wondering what size jets I Gould go to? I have 33 smoothbores. Gpz head, 10 25 1 comp pistons, Andrews mild cams, k&n pods, kerker exhaust. I put 140 jets in and the plugs still looked way lean. I have to order them online so it's a guessing game for me that can get expensive. I tried drilling them but it's not to accurate! I'm up to a 3/32 drill bit an they still look lean. I think the jets go up to 240 so I dnt know where to start! Also wondering if pilot needs done! Thanks guys

How does the bike run, if it runs good then leave it alone. My experience with the modern blends of gas, plug reading is getting unreliable.

boose wrote: Wondering what size jets I Gould go to? I have 33 smoothbores. Gpz head, 10 25 1 comp pistons, Andrews mild cams, k&n pods, kerker exhaust. I put 140 jets in and the plugs still looked way lean. I have to order them online so it's a guessing game for me that can get expensive. I tried drilling them but it's not to accurate! I'm up to a 3/32 drill bit an they still look lean. I think the jets go up to 240 so I dnt know where to start! Also wondering if pilot needs done! Thanks guys

What engine displacement?
33's are imo too large for most Kaw large fours.
At least with regard to tuning the full range.

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Good Fortune!

how many cc's. i ran rich with 140's on my 1135 motor. but it ran good. dont worry about color on the plugs .with modern gas, it takes a lot more miles to get color.
time how long it takes u to increase 20mph in 4rth or 5th gear at WOT. best jets produce the best time.

on an 1170 gpz motor, 132.5 main, 30 pilot and needle raised one notch

how does it run? i push my mixture towards very clean plugs in my racers.

if it stutters and overheats, cant WOT, etc. , then yes, 140 and still lean sounds odd,

maybe try raising the needles some?

drilling jets never a good idea.....

found that dell'orto makes super cheap jets with 5mm and 6mm that work well on Japanese carbs, SUDCO jet prices are a bit of a scandal

TG