jetting ?'s

[DannyMK2]

my buddy just picked up a warrior that needed some TLC. it had a pro circuit pipe and a k&n filter with outerwares on it. looks like a stock header pipe. we cleaned the k&n, but its still running rough, feels like its leaning out and needs a jet kit. previous owner probably never even thought to do it. anyone have any idea what size jet we should order for it? also, where is a good place to order jets from? thanks.

 

[lbjamm]

Try the search. Been discussed several times.

 

[DannyMK2]

i did search, but maybe i should elaborate. i was kinda hoping that somebody had a similar set up and could comment as to which jet worked for them. i know thats kind of a loaded question but i figured it would be a good starting point. for what its worth, we are at or just above sea level.

given that the only mods to the bike are the intake and exhaust, would the pilot jet need to be changed, or can that be left alone?

i dont see the bike needing a jet bigger than 150, truthfully i think it might only need a 147.5, but again, looking for input from those with similar set ups so i have a range of jets to order. i see jetsrus offers the warrior jet kit, but thats only main jets and they range from 150-170. seems to me like that would be a bunch of wasted jets that didnt need to be purchased in this situation.

aside from jetsrus or the dealer, is there anywhere else i should look for jets or is that pretty much it?

 

[scottdatv]

For a stock Warrior with a pipe and an OPEN airbox w/ K&N, you will most likely will require a #152.5 or a likely #155 main. I also suggest going down one clip position (raising the needle from #3 to #4 position from top)
Pilot jet remains the same, but turn the mixture screw out from lightly seated an extra half turn to 2.5 turns out.
This should work well for you.

 

[scottdatv]

Check with your local stealer on the main jet purchase, or you can also pick these up on eBay sometimes for a great deal. Ask for the Mikuni large round style mains. Sudco is also a good supplier

 

[DannyMK2]

For a stock Warrior with a pipe and an OPEN airbox w/ K&N, you will most likely will require a #152.5 or a likely #155 main. I also suggest going down one clip position (raising the needle from #3 to #4 position from top)
Pilot jet remains the same, but turn the mixture screw out from lightly seated an extra half turn to 2.5 turns out.
This should work well for you.

its not an open air box if that makes a difference. factory style drop in k&n. box is not drilled either.

 

[THORrider05]

Procircuit doesnt require to rejet. Im running there exhaust with stock jetting. I called and asked what jetting they recommend and they said stock.

 

[THORrider05]

Ive ran jets from 147.5,150,155 and they run to rich with those in. I put the stock 145 in and runs perfect. I also have no airbox just a uni pod filter on the carb, vitos key and cam. The higher elev i get into it starts to run rich with any jets other than stock, lower elev i could MAYBE get away with the 147.5

 

[DannyMK2]

Procircuit doesnt require to rejet. Im running there exhaust with stock jetting. I called and asked what jetting they recommend and they said stock.

interesting. maybe the combination of this with the k&n is causing an issue. this thing is backfires like crazy when you let off the throttle. runs a little rough and def feels like it needs a jet.

 

[scottdatv]

If it backfires on decel, then you are too lean. That is the function of the pilot jet circuit / mixture screw setting, and also the air cut-off valve. You may have a bad air cut-off valve diaphragm bad and/or a cracked cover. That's the white plastic cover you see on the side of the carb. Check that out and see where it takes you.

 

[Allen3321]

scottydatv

would the air cut off valve also cause my 02 warrior to die during a fifth gear run at 1/4 to 1/2 throttle? I took mine off and it was pretty nasty, a dark silvery tarnish all over the valve "needle". I cleaned it with carb cleaner and my finger to get as much off as I could. I could only spray cleaner into the "valve" seat as I didn't have any pipe cleaners handy. The idle became much smoother then the issue of shut down happened. I can run it in fourth at 1/2 and it will run fine, anything more and it will die. Your help would be much appreciated.

 

[lbjamm]

No, it only cuts the air during decelleration.

 

[Allen3321]

Well crap.

HMMM :argh: I'm at a loss then. Any other suggestions? I'm wanting to :atv:

 

[lbjamm]

What mods do you have? What's your jetting? How's your plug look? How's the flow from tank to carb?

 

[Allen3321]

mods

white bros. exhaust, stock jetting, fueling is good and new plug.

 

[lbjamm]

What color is plug? Might need to up your main. Was it running good before?

 

[Allen3321]

Its a brand new plug. It ran ok. Not at its peak though.

 

[YAMAHAULER]

well knowing what color the plug is will let you know if the jetting is off or not
White or Greyish color= lean
tan to dark brown = good
Black = rich

you need to do a plug chop at 1/2 throttle and another at wot each time with a new plug then you will know if your needle needs to be adjusted up or down or the main jet bumped up a size or 2

 

[frit91]

If you would like a starting point of reference, I can help ya out with that. My buddy/neighbor has a white bros e series pipe and drop in k&n filter and no other engine mods. Altitude is about 680 ft. He has a 147.5 main, 45 pilot, left the needle alone, fuel screw out 2 turns and it runs great. Plug stays a consistent chocolate brown color.

 

[Allen3321]

Hey thanks alot for the info guys very helpful!