Jets for my setup???

YN89 · Aug 27, 2011

Hey guys I've got a 05 raptor and just recently installed a fmf powercore4 exhaust with a fmf powerbomb header and a unifilter..I haven't re-jetted yet coz I just don't know what sizes to use where I ride is elevation/altitude/height above sea level of -0.00162 m above sea level. Can someone tell me or point me in the right direction on what jets to use?? Thnx

duneracerweston · Aug 27, 2011

pull the spark plug and look at the end of it if its white its lean tan its perfect and black its rich and to adjust jet sizes you really need to see how it running now and what jet sizes are in it already

elwood · Aug 27, 2011

most likely up your main 1 to 2 sizes depending on what it needs. !st you have to pull the main jet to see what size is in there. And checking your plug will tell alot about how it's running

YN89 · Aug 27, 2011

When I get home from work I'll check it out thanks fellas

YN89 · Aug 29, 2011

i pulled out the spark plug is all black alround the centre and side electrode soo its rich right?? but my exhaust pops everytime i get off the throttle and the header right at the start of it gets cherry red (only visible at night) i took out the carb to look at my jet sizes like elwood said but the dumb ass i am i didnt record it and i put the carb back on the bike.....i hate re-installing that lil throttle cable clip =,(

duneracerweston · Aug 29, 2011

You pilot is lean if it pops on decel and I think ur main is a tad rich which shoud be fiine

YN89 · Aug 29, 2011

I opened up the carbi again the main jet is a 142.5 and the pilot jet is 70...

elwood · Aug 29, 2011

142.5 is stock size main and 22.5 is stock pilot jet for a raptor 350. So I think you're way rich on the pilot and lean on the main. I would try upping your main jet a size or two and lowering you pilot a few sizes. Put the needle in the middle slot, then put in a new plug and run it. Tell us how it acks and what the plug looks like.