88 lt250r. paul turner pipe & silencer,clamp on k and n. stock pilot is #30 and stock main is 240. right now i have a 37.5 pilot and 280 main. doesnt want to rev high enough unless the air screw is like 2-3 turns out. i know with my mods and the right jetting the air screw shouldnt be out that far. it is very easy to start,like first kick. but it is harder to start with the choke on,and if you start it and then put the choke on right after it will stall. i did a plug chop w.o.t. in third gear and it seemed ok(darker brown) for that range. but i let it idle for like 5 minutes (air screw 2 turns out) and the plug was wet but really light greyish colored. if you turn the air screw out 2 turns there isnt any smoke at idle,but all the way in it smokes a lot at idle. should i go down a step or two on the pilot? i need expert advice,i have spent to much money to mess it up

 

We need to get something out of the way first...
Is the carb the original carb? If so has the needle jet and needle been replaced? If the needle jet and needle are the original ones or have been in there for several years then dont do any jetting or pull your hair out until you replace them both. Mikunis are famous for giving jetting fits when these components are worn. After you replace then you will find that many issues will go away and changes to jetting will be more definite.

 

yeah it is the stock carb,i replaced the needle already,but i havent replaced the needle jet

 

i have a 40 pilot and a 270 main, it runs great, but screw is also out about 2 turns.

 

super, replace your needle jet and you will solve any tuning issues, I PROMISE. If the needle had any marks on it what-so-ever then the needle jet is worn.

 

im going to order the needle jet tomorow.and go down one size on the pilot. the one thing that worries me is: i let it sit for like 5 minutes started,with the air screw all the way in,and it was smoking pretty good cause of the air screw being in.,and when i checked the plug it was wet,but the porcelan was light grey,but the plug was wet,is that normal? it seems like im getting enough gas,cause of the smoke and then the plug being wet, btw: im not losing any coolant. is it ok for the plug to be light grey after idling? it was wet. i always thought after idling that long the plug was suposed to be blackish. i am not losing any coolant or tranny oil. and i know the air screw is working cause it will smoke a lot while its turned in,and less when its turned out.

 

I will take more than a few minutes to start getting some dark color on the plug. Most of the time you need some driving to load the motor and heat the plug. Letting the motor idle wont produce enough heat to blacken the plug very quickly. Chances are you might foul it before that happens. Almost any 2-stroke regardless of how well it's tuned will tend to load up after idling for a bit. If the plug is staying wet then you are ot lean for sure. A lean condition will show an ashy dry color. Being you have the clamp on filter I would go down to the 35 pilot to start with.

 

Both my 86 and my friends 91 LT's jetting greatly improved after replacing the needle jet.

 

thanks for all the help guys,im just trying to be more safe than sorry,first time i rebuilt this engine i blew it up in like an hour.ive spent like 6-800 bucks on it.just trying to be safe