couple ?'s bout jetting

jgray44 · Mar 30, 2011

so i had a spare carb off a parts wheeler (94 warrrior) and i wanted to take the carb apart to see the guts and how to jet and what not. i took the manual and got it all apart and it was alot easier than i thought. i didnt realize that the main and pilot jets are RIGHT next to each other. i just have a couple questions.

1. once i up my pilot jet to a 45 do i ever have to mess with that jet again? i dont wanna buy just one pilot and then find out i have to change it also

2. do i have to keep taking the carb off to change the jets?

3. the plug is black, so that means i need to downsize just the main jet right?

and last, if i cant get it jetted by this weekend will it hurt at all if i run rich for a few hours?

elwood · Mar 30, 2011

if you up your pilot to a 45 and you ggod to go, if for some reason it's to rich at idle put the 42.5 back in, but I dout it will be. yes black normally mean rich so downsize it one size. When I change the jets I unbolt it from the intake boot and airbox then turn it on its side. There might be an easier way but that's how I do it. And last running rich is ok it wont blow your motor or anything. But running it lean will toast your motor

jgray44 · Mar 30, 2011

k its black but not like super black so i must be close, thats a big relief. carbs arent really that hard anymore

. thanks bunch elwood

jgray44 · Mar 30, 2011

one more thing, how long should i ride before checking the spark plug?

elwood · Mar 30, 2011

to do a plug chop I've been told to run it up through the gears and then hit the kill switch while riding ang still holding the gas. Get it stoped and plug the plug. Might be a better way, anyone want to ring in?

bomber315 · Mar 31, 2011

yeah supposedly when you read a plug it is showing you how it is burning for the last 30 secs (or so) that the motor was running... so if you putting around for 3 miles and then shut it off and look at the plug then you are reading how the needle is (not pilot, thats is for lower than "putting around", like idle).... now if you go blasting down a dirt road for a mile and plug chop it at WOT, keep the throttle open and get stopped asap, then you can read the main jet...

however having said this i find that todays gasoline is hard to read... it seems to take FOREVER for a plug to turn ANY color (im thinking because of all the "cleaning agents" in gas)....

one thin is for certain if you put a black plug in it and it turns white at WOT you are too lean.... also at night if your headpipe glows past the first say 5" then you are too lean... i beat the living **** out of mine and the stock headpipe glows for 5 inchs and i have never had a problem...

also i am running a 150 main jet, it runs great, if i put a 155 in it spits a stammers on top end like it is hitting a rev limiter. obvisously too rich

elwood · Mar 31, 2011

bomber315 said:
if i put a 155 in it spits a stammers on top end like it is hitting a rev limiter. obvisously too rich

Should have seen mine when I put a 160 in it. lol

bomber315 · Mar 31, 2011

elwood said:
Should have seen mine when I put a 160 in it. lol

it is stammer and spit and sputter like it was hitting a rev limiter? if so i would like everyone to make note of that, its not running out of gas like most people think it is actually getting to much

elwood · Mar 31, 2011

yep like I hit a rev limiter

barncat · Mar 31, 2011

Glad I clicked on this thread.
I JUST finished putting my 150 main in, and went out, and it was like I was hitting a limiter.

Before my airbox mod, it was the same thing.
It has a 147.5, and I didn't run it long with it in, and just swapped the jet out. So looks like I'll be putting it back in, and trying it again.

ALSO, where is the fuel/mix screw. I think I know where it is, but I'm not for sure. And if it''s the one I think it is, I can't get it to turn.

jgray44 · Mar 31, 2011

going along with the fuel mix screw, its on the bottom of the carb just a little flat screw thats almost flush the the carb.

i have a question bout it, if i punch my gas it bogs down and wants to die, carb is clean, should i adjust this screw to fix that or do i need to adjust the idle screw? if so, which way should i turn the screw?

edit: or will doing the accel pump mod work for it

barncat · Mar 31, 2011

Ok, found that. Wasn't sure on it. I just went and checked mine. It was out 1 turn.
That should be lean correct?
I backed it out a full 2-1/4 turns.

If I was cutting out with to much fuel with a 150 jet, but the mix screw was lean? Is it a valve issue.
Should I put the 147.5 back in?
I really hate rapping this thing out, sounds like hell at full throttle.

I have plenty of power, until I'm at W.O.T. and that's when I notice the issue.

elwood · Mar 31, 2011

jgray44 said:
going along with the fuel mix screw, its on the bottom of the carb just a little flat screw thats almost flush the the carb.

i have a question bout it, if i punch my gas it bogs down and wants to die, carb is clean, should i adjust this screw to fix that or do i need to adjust the idle screw? if so, which way should i turn the screw?

edit: or will doing the accel pump mod work for it

air fuel should be around 2 to 2.5 turns out. if you have to turn it in more than 1 full turn down size your main, if you have to turn it out more then 1 full turn up your jet. If it bogs when you punch it it could any of the 3 you listed. I would try with the idle 1st (easiest)

elwood · Mar 31, 2011

barncat said:
Ok, found that. Wasn't sure on it. I just went and checked mine. It was out 1 turn.
That should be lean correct?
I backed it out a full 2-1/4 turns.

If I was cutting out with to much fuel with a 150 jet, but the mix screw was lean? Is it a valve issue.
Should I put the 147.5 back in?
I really hate rapping this thing out, sounds like hell at full throttle.

I have plenty of power, until I'm at W.O.T. and that's when I notice the issue.

Are you at a high elevation? higher elevation = less oxegen less oxegen = leaner jets

barncat · Mar 31, 2011

I'm at 867ft so I'm in the 0-2000' range. The dealer didn't have the replacement 45jet.

When I checked the Fuel mix screw it was 1 turn out, and with the 150 jet, and open lid, I was cutting out at full throttle.

I never checked W.O.T. with the 147.5, and the screw at 1 turn out. I am going to put the 147.5 back in, with the screw 2.25 turns out, and see how it runs.

elwood · Mar 31, 2011

let us know how it goes

barncat · Mar 31, 2011

So, for clarity. Backing the mix screw out, lets in more air, correct?
If popping occurs from to much fuel, is the 1.25 turns OUT that I turned it, going to make that much difference at WOT?

elwood · Mar 31, 2011

popping through the carb=lean
popping through the exhaust=rich
both are for when you are riding and let off the gas

elwood · Mar 31, 2011

turning the screw more then 1 full turn means you should change the jet. turning it in is leaning it out.
turnong it out is richening it up

barncat · Apr 1, 2011

Cool figured it was that easy, just wanted to make sure.
'Sorry about the thread jack jgray.

couple ?'s bout jetting

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