Help tuning

[1987 Warrior]

Hey guy i need a little help tuning my warrior.
I just put a factory airbox on and my bike and it sputters and backfires like a bitch i checked the spark plug and its black so i know its running rich.
it has a zoom zoom carb with the stock jets in it.
what im wondering is there a way to lean it out besides putting smaller jets in it. it used to have the airfilter mounted directly to the carb and ran great, the reason i put the airbox on is because i play in the mud alot and do a bit of water crossing and i didnt like the idea of having water and mud beaning able to get directly on the filter.

any help is much appreciated
1987Warrior

 

[1987 Warrior]

Another thing while im riding it will randomly find neutral while shifting between any gear would that be a sing that my clutch is on its way out?

 

[2000]

The stock jets should work fine but I would try a 145 main jet if your exhaust is stock.

 

[1987 Warrior]

i have a pro circuit t4 exhaust

 

[lbjamm]

Lid on or off the airbox?

 

[1987 Warrior]

Lid is on

 

[lbjamm]

Yeah. 145

 

[1987 Warrior]

isnt a 145 main the stock size?

 

[alex456123]

yes. you wont normally need a bigger jet if you are not taking in more air, even you are flowing exhaust out faster.

 

[1987 Warrior]

so what should i do im kinda lost here.

 

[lbjamm]

You could try removing the lid. Is air filter clean? What jets are in the carb now?

 

[1987 Warrior]

airfilter is brand new and the jets are the stock ones

 

[lbjamm]

Have you actually looked at the jets to see what size is in there?

 

[1987 Warrior]

sorry no i havent looked to see what they are i just assumed they would be the stock one as that was what they said when i bought it, ill have a look at it tomorrow

 

[1987 Warrior]

ok guys so i finally got to work on my quad. So it has a 145 main jet so should i go to a 140 or a 142 if there is one? i would look at the needle position but dont remember were to look for it. also i noticed the accelerator pump is sticking so im going to do the bic pen mod.

 

[sickofit]

Hi man...noticed you're in Ontario...where are ya located..??

Trouble is with the zoom zoom carb,is I would think they wouldn't be genuine mikuni jets,but chinese knock-offs...I'd use the carb no prob,but I would order a mikuni 42.5 pilot jet,as well as mikuni 142.5 145 and 147.5 main jets to get you dialed in with the lid on.

Also,what is the pilot screw set at..??...Should be set just rich enough so you don't get backfiring on long decel runs....1-1\4 to 2-1\4 turns out from fully seated lightly.

 

[1987 Warrior]

hey i live in Brechin your about 2-1/2 hours away, and the pilot screw is at 2-2-1/4 turns. i have my old carb still so ill swap the jets and see how she runs and let ya know.
and thanks for the help

1987warrior

 

[bones]

more ontario boys ... why didnt you just rebuild the stock carb

 

[1987 Warrior]

i was having to many problems with it so i said screw it and bout a zoom zoom

 

[1987 Warrior]

So i swapped my jets to mikuni 145 main and a 42.5 pilot and i still runs the same as the zoomzoom jets that were in it(same size). would moving the needle position help with my proplem?