250 SX Jets????????

[ewalker302]

My 86 sx has a cobra pipe, and uni filter, with the lid on. It has the stock jetting, and backfires on decel.

I wanted to order a couple main jets from dennis kirk, but they are all listed by carb series (13, 21) or by prefix (KJ, CR).

Can anyone tell me which jets are right for my carb??

Also if you are running a aftermarket pipe on a sx, what size main are you using??

I was planning on getting a 135 and a 138, and see which was better.

[mad_max]

...Also if you are running a aftermarket pipe on a sx, what size main are you using??

I was planning on getting a 135 and a 138, and see which was better.

I've got a SuperTrapp w/ 14 discs...I've got a 140 jet w/ a K&N and no airbox lid.... I'd call it slightly rich. You might want a 135

[Dirtcrasher]

If you can get to a dealer you are better off than through DK and probably cheaper too. These SX carb type jets don't seem to be laying around as much as other hex head style mains but they are out there. I just find that no one helps over the phone and you have to get in there for some "real" help sometimes. You may find you still backfire even after you upsize the main jet. If you back out the airscrew a 1/4 turn at a time after the correct main jet gets in there it will fix the snap crackle pop. I'm at a 138 with a Cobra but it could go up another step or 2.

[ewalker302]

I know I could get the jets from the dealer, but I am ordering some other stuff from dennis kirk for my 400ex anyway, so I figured I could get some jets for the sx cheaper while I was ordering, I just dont know what series main jets to order. I was hoping they wold be somewhat standard.

When I cleaned out the sx carb, the pilot jet was clogged, and would not clean out. Luckily, the old pilot from my 400ex carb was exactly the same as the stock pilot for the sx, so I swapped them (I had went up on the pilot for the ex), and I noticed that the mains were a different type (sx-ex).

If anyone knows what the series or what prefix the main for the sx is, I would appreciate it..

[Dirtcrasher]

Good luck then, even when I gave the clowns the carb model # they couldn't help me - thats why I ended up at the dealer....