Main jet adjustments

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I am in Florida and had to put in 165 mains for it finally feel right up top. Still sorting out the middle with 177 PAJ2 4th lot up from pointed end with one washer. Got all the backfires out of it with adjusting the needle to this point but when I WOT in 2nd at about 2k or in 4th at 4k it still a little sluggish until it gets to about 5700-6k then it takes off like a rocket. Morley Kit with 4-1 Kerker
 
New update. When adding a shim to the needles, I noticed that the plastic spacer was upside down on all four needles. The plastic tab that is supposed to fit in the gap on the needle clip was facing the wrong way, so I suppose that was like have a couple shims on the needle. I did not add any shims at this time, because now the whole scenario has changed. I had already put in 162.5's. When revving the bike in neutral, it is not very smooth, and at about 4k starts popping out the exhaust. Do you think I should go back down on the main size? The popping would indicate too rich wouldn't it? I know this bike has so much potential, but not being able to get at it is driving me nuts. If it ran good enough to sell, I'd consider it (not really).
 
When revving the bike in neutral, it is not very smooth, and at about 4k starts popping out the exhaust. Do you think I should go back down on the main size? The popping would indicate too rich wouldn't it? I know this bike has so much potential, but not being able to get at it is driving me nuts. If it ran good enough to sell, I'd consider it (not really).

Is your airbox on or off when your revving it?
 
hay goatman did you sort it out? what size main jet did you end up with.im having the same issue.
 
No, not sorted yet, no time. I will try 165's hopefully this weekend and post results.
 
im at mikuni 165 stock needles morleys kit and it still breaks up around 6500-8000.but when changing jets and testing i didnt put the faux tank on.when i put the tank back on the problems cleared up no breaking up very smooth.there must be a lot of turbulent air on top of the panel filter at speed whithout it.so i now think i might be rich at 165 main so im going to test progressivly smaller with faux tank on and see what happens.ill post results if interested.i suspose when tuning on a dyno this wouldnt happen as theres no wind.has anyone else encountered this.
 
This is normal. The only time to do any testing w/o air box lid is as you say...in a dyno room or sync-ing carbs, etc.
 
This is normal. The only time to do any testing w/o air box lid is as you say...in a dyno room or sync-ing carbs, etc.
do you mean the panel filter ala morleys jet kit or the faux tank that fits on top.as i talking about the faux tank on top.i had it off because it was being painted once i put it on all problems dissapeared.
 
The faux tank. Morley air box doesn't work well w/o it. Stock air box would be fine.
 

Latest posts

Back
Top