I bought a used 97 Warrior and I have been going through the bike mechanicaly and I took the plug out and I see that it is black and I know that this means that it is running rich, I asked some motorcycle friends about it and one told me that most manufactures jet them rich when they build them and just leave it alone unless you are gonna race it but the Climbers manual does say that the plug should be tan around the tip.

Should I rejet it or leave it?

By the way if I hit the throttle fast it bogs down pretty bad. I has caused me to kill it in the middle of steap hills. is this the from the needle clip setting being to lean? (which I did move)
I did put it back to the middle setting but I haven't put the carb back on yet. I wonder if it is something else. The accelerator pump does seem to be working.


thanks

Bill

 

it wouldnt hurt to lean out your carb it will help it run better. just make shure every time you change your main jet make shure that you do a plug test(kill your quad at full throtle and pull the plug to make shure it isnt to lean)and remember if the engine ever sputter or skips at full throttle let of imeadatly or you will melt your piston.


1990 polaris trail boss 350L 4x4

 

The first thing you need to find out is where on the band it seems to be rich. Since you bought the bike with the plug in that condition I wouldn't change anything until you know what, if anything, needs changing. I would first install a new plug. You've already returned the jet needle to the nominal position and that's good. Now run a test at 3/4 to full throttle for a mile in whatever gear you need to use; your engine doesn't know or care what gear you're in, only that it is at 3/4 to full throttle. At the end of the mile, STOP! Pull the plug & read it. Not only the electrode but the insulator down inside. As you already know, the magic color is tan or light brown. Black or very dark is rich. The stock main jet is a 145 so if the plug tells you it is rich you need to determine what size main jet you have & reduce the size accordingly. When you have finished jetting your main then you can test ride at 1/4 to 3/4 throttle to check jetting on the needle jet. I'd bet it would be okay. As a final test, check performance from idle to 1/4 throttle. This is the pilot jet circuit. The pilot screw's (which is next to the drain plug on the bowl)nominal setting is two turns out from seated (gently).
BTW,regarding the loss of power on steep hills; depending on the steepness, the power loss could be cavitation caused by the extreme angle of the carb causing the fuel to slosh & the engine to starve for fuel.You might check the level of the floats to be sure they rise to spec.

 

Is it a new plug? If you're not sure, install a new one and ride for a few days.

The Warrior isn't typically exceptionally rich from the factory. If the bike is completely stock, jetting should be fine, unless you're running at higher elevations (over 3,000 ft).

Another thing, make sure you're reading the plug correctly -- don't look at the tip, look down into the ceramic part.