jetting questions before the break in

npan1029

New Member
Feb 15, 2010
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Central Jersey
so i can finally fire up my blasty this week but i really want to get the jetting close before i do so. the reason why it blew up in the first place is because of too lean jetting so im never going to make that mistake again. i know people dont like to give out too much jetting tips because everyone's quad is different. well i just want some tips on what jets to get to get me in the ball park. right now it has an fmf exhaust, ported cylinder and milled head, stock air box with uni and no lid. the carb im running is a 30mm mikuni carb that right now has a 250 main jet and a 40 pilot jet and it runs rich. again im just looking for some suggestions on what jets to buy.
 
are you sure it runs rich on the main???? i would think with a ported motor you'd be looking at a 300-320 on the main jet, but your pilot may be a little large
 
are you sure it runs rich on the main???? i would think with a ported motor you'd be looking at a 300-320 on the main jet, but your pilot may be a little large

well to be honest i dont know yet after the porting. when it wasnt ported it ran really rich with the 250 main but would the porting make the main go up that much?
 
if its a good port job.....if it was running rich then how did you blow it up running it lean?

my bike with no lid, UNI, and fmf was in the ballpark with a 280 main in a 36mm mikuni....
 
if its a good port job.....if it was running rich then how did you blow it up running it lean?

my bike with no lid, UNI, and fmf was in the ballpark with a 280 main in a 36mm mikuni....

lol i should have specified that im sorry. it blew up from running lean because the stupid kid i bought it from gave me a 140 main jet for it and said that was what it needed and not thinking i put it in and then boom it blew up. stupid, i know, but if it didnt blow up, then i wouldnt have gotten it ported and all that stuff.

but the main jet that came with the carb when i bought it and it was running rich was the 250 main so i was going to put that in for now and just go from there because i rather run rich than lean obviously but now you think im going to run lean with that. so youre thinking i should buy some bigger main jets and maybe go down on the pilot?
 
go ahead and try the pilot for now, playing with the air screw will tell you if you need to go down on the pilot. but i'm sure you're gonna need more than that 250
 
go ahead and try the pilot for now, playing with the air screw will tell you if you need to go down on the pilot. but i'm sure you're gonna need more than that 250

well thats good to know lol. so im not going to even start it with the 250 in there. im going to order some jets. in your opinion what sizes do you think i should order?