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Jetting Question
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Posted by: 03pete

First off, I am horrible with jetting, and I dont even know where to start at.

I have a 1985 LT250r that is freshly bored .060 over, weisco piston, fmf pipe and silencer, and k&n filter with no airbox.

Its summer here, so temps are 80-90, and my elevation is 600 feet.

What should my main pilot and needle be at? as i said i am horrible with jetting so any help would be appreciated.

Thanks

Posted by: weld_13

What jets do you have in it now and what is the plug like after regular riding and after a plug chop?

Before the triple digit temperatures set in I had a 30 pilot and 230 main at 2 3/4 turns out on the air screw and my plug was dialed in brown.

Posted by: 03pete

I dont know yet, i Just got it bored out and I am picking my cylinder up tomorrow. Im actually not sure what I have in there now to be honest, but i will check. I went from .020 over to .060 over, so I know it will need more fuel.

Is yours standard bore or overbore?

Posted by: 03pete

This is your main jet correct?

If so, the number on it is 327. Does that seem right?

Posted by: 03pete

oops forgot pic.

Posted by: 03pete

nevermind, this is the jet. Sorry, im so bad when it comes to carbs lol. I have a 210 in there now, is that good or bad? Before i bored it out and blew my piston my plugs were always black, so maybe this will lean it out just right.

EDIT: My Pilot jet is a 45.

Posted by: weld_13

quote:
Originally posted by 03pete
oops forgot pic.

Why did you pull that out of your carb? But yes the second picture is your main jet.

I have an 89 lt250r carb and the pilot circuit is set up a little bit differently(I've seen both, I used to run a 86 carb) so that's why my pilot is different, I'm also running a open k&n so my main jet will need to be richer.

Guys seem to run a 45 pilot and between a 210-230 on the 86 carbs so it sounds like you're pretty close, I bet just some adjustment on your air screw will dial it in perfectly as long as your needle is set right.

Posted by: 03pete

quote:
Originally posted by weld_13
Why did you pull that out of your carb? But yes the second picture is your main jet.

I have an 89 lt250r carb and the pilot circuit is set up a little bit differently(I've seen both, I used to run a 86 carb) so that's why my pilot is different, I'm also running a open k&n so my main jet will need to be richer.

Guys seem to run a 45 pilot and between a 210-230 on the 86 carbs so it sounds like you're pretty close, I bet just some adjustment on your air screw will dial it in perfectly as long as your needle is set right.

I honestly, have no clue where the needle is to move it?

Posted by: weld_13

The needle that is on the bottom side of your carb slide, I would leave it for now, it's probly fine since it sounds like the previous owner already had it jetted correctly.