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pwk 28's ..... i'm paranoid with my jetting


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Setup:

800 -1200 elevation (for starters)

 

Port Cleanup

20cc domes w/ Noss Head

.10 Over Bore

pwk 28's

vf3's

toomey t5's

and a high performance boost bottle (just kidding lol)

 

Jetting Currently:

n68a Needles on 5th position (richest)

52 pilot

158 mains

 

It still feels lean, especially at idle. I was thinking 62 pilots and going up to 165 on the mains.

 

The motor is getting hot as shit and I have that noss head, billet impeller, larger radiator, and engine ice.

 

I read on a thread on here that a 175 keihn is like a 330 mikuni, is this true? If that's the case I need way bigger

 

Any suggestions?

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i ran a 140 main with similar mods at 1500-1700ft with those carbs.

 

that's insane.. mine sounds so lean still, new carb boots, new cross over tube, new clamps, new gaskets, new head, new o-rings, i know it's not got any air leaks

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How do you know it doesnt have an air leak?,start closing the air screws if it starts idling down n wants to stall your not lean on the pilot.wherever you heard that jet croossover number its not close nor do either carbs pull fuel the same way(jet cuircitry

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How do you know it doesnt have an air leak?,start closing the air screws if it starts idling down n wants to stall your not lean on the pilot.wherever you heard that jet croossover number its not close nor do either carbs pull fuel the same way(jet cuircitry

 

I have the idling perfect now actually, synced and everything. I just feel that it's lean, the motor did not get as hot as fast before.

 

It has low end like a raped ape, but I figured that was due to the lean conditions as well

Edited by justinkk2005
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I have the idling perfect now actually, synced and everything. I just feel that it's lean, the motor did not get as hot as fast before.

 

It has low end like a raped ape, but I figured that was due to the lean conditions as well

 

Or your banshee was in a coma due to a way rich jetting with the other carbs. Why would you jump from a 52 to a 62 pilot all in one shot. Jumping up 4 pilot jet sizes at once is quite a big change.

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Or your banshee was in a coma due to a way rich jetting with the other carbs. Why would you jump from a 52 to a 62 pilot all in one shot. Jumping up 4 pilot jet sizes at once is quite a big change.

 

It was 350 mains and 30 pilots with the stock carbs and it ran great.

 

I know what i'm doing, i didn't say I was going to make that big of a leap right off I just ordered 55's, 58's and then 62's.

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need needle.

 

if the needle is as rich as possible it will NEVER run right needles are designed for center or one clip lean or one clip rich the last 2 clip pos's on the top and bottom the the needle are for jetting help they are there to help the tuner kinda understand what the motor wants.. you should probably start with a KNOWN needle that works in those carbs. THEN jet from there you cannot state jetting for a needle that is possibly not used in others carbs.; depending on needle taper and diameter, will affect the ENTIRE jetting range. and cause you to have weird slow and mains compared to someone with a diff needle. the slide cut out also matters. the only needles i have much experience with on pwk's is the custom needle that LRD did for that carb with that needle i usually ended up in the 35-42 slow jet, and between 140-165! mains' motors are differnt and they all just need jetted specifically to what the motor wants...

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I have tried the JJH and the n68a, both common needles for the pwk 28's on a banshee and it at least runs decent with the n68a.

 

They're so expensive it's hard to just keep buying them, $25 a pop for a set shipped.

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Im new to the banshee world but have modded sleds extensively. But everyone who mods a sled has a EGT (exhaust Gas Temperature) gauge. They are most useful for tuning at WOT which wont really help your pilot jet but will help dial in your main. I am not sure why people do not run them on their handle bars on Shees. THey are a few hundred $$ and make tuning for the edge easier. Just do not exceed 1250 degrees on long pulls and your set. made tuning my n2o fed skidoo a breeze. (it has a Boondovker Fuel Box but principle stays the same, too hot, add fuel, too cold, subtract fuel)

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