I need some help after i installed my complete fmf exhaust ( powercore 4 and the powerbomb 0 it stoped running. It ran before i put the exhaust on. So i guess i need some jetting help from you kawi drivers. Stock klx250s with no air breather mods except the complete exhaust . Please help me with my jetting process oh and i live a 800 ft above sea level.

I'm thinking of puting a 130 or a 132.5 ?
I'm not sure need help

 

Could you elaborate on the, "it stopped running", part? My darkest thoughts are that you installed the exhaust, ran down the highway at WFO, and burned a hole in the piston. Yeah...that's pretty dark.

On the other hand, since you apparently made no intake mods to get more air into the engine, perhaps...and hopefully so...I'm just pessimistic. As I asked, could you expand on the "stopped running" and what happened up to that point...such as...did it run at all, or quit after running for a bit?

On jetting, to get full benefit of an exhaust system, it's probably not worth even doing unless you're going to open up the airbox and rejet accordingly to take full advantage.

 

It ran 3 hours before with all stock parts and then i put on my fmf complete pipe kit and it never started thats with stock jetting of cours wich is what i need help with. I'm not sure on what jets to use.

 

broncoman, it's possible you have another problem. I'd think the bike would at least restart regardless of what exhaust system you installed. Even if you apply the choke to an extremely "lean" engine, it should fire up. Yeah, it may not run great, but you should get it to run.

Did you do anything else to the bike while installing the exhaust? Pull the tank off, do some other mod? Something that might have unhooked a wiring connector or such? Is that pipe shipped with some kind of stopper or packing that might still be in the pipe/muffler?

I'm not sure jetting is your problem at this point. If you apply the choke, that bike should fire up. Is the starter cranking with some authority? I'd check the normal routine of air, fuel, and spark. All 3 have to be present obviously. Start by pulling the plug wire and sticking another plug in the cap and grounding the plug against the engine. Crank the starter and see if you get any spark...or get the thunder shocked out of you.

 

^+1 the ride should fire up with the choke being used. Looks like it is time to double check your connections (electrical, vacuum or fuel related). Do not forget to make sure that the kill switch is in the on position.

 

yea , i'd have to say that it has nothing to do with your exhaust-try everything else.

 

+1 on the kill switch. That one has gotten me before.
Gas in tank , fuel on.
Good luck

 

+2 Check air/fuel/spark

Pull the spark plug, make sure it's clean/dry.

 

It has spark and fuel etc. So i put a 130 jet and it ran but horible it boggrd down and was hard to get passed 6,000 rpm < so there for i beleive i need more fuel what do you think...

 

Bronco, I still think something else is going on. I've got all the mods except a big bore kit, and mine is running a 128 main...albeit at a little higher elevation...approx. 1500. Without the airbox mods that you indicate weren't performed, a 130 main is more than enough...maybe too much. Is the main jet all you did to the carb? Is the airbox and filter still OEM? Most carb mods include a minimum of raising the needle, a bigger main jet, drilling the carb slide, and playing with the air/fuel screw. I'm still wondering what leaving the intake and carb stock and adding a full aftermarket exhause does to the jetting requirements. I've always jumped in with both feet and done most all intake and exhaust mods in one attack. What finally got your bike to restart after the initial attempt?

Be honest here...have you done any mods like this before?