hmf jetting, How 'bout it, come on

[sgtstadenko]

Sorry about this guys I know there are hundreds of jetting questions on here but none answered mine. I just bought a hmf slip on. I plan to run stock filter with lid on. A friend says I probably wont have to change anything but the main and maybe turn my screw out a little. Performance wise I'm cool with it I really just want the sound. But I dont wanna damage anything. Oh yeah and hmf sent me a 165 main. Whacha think?

yeh that might be a lil rich runin a stock fliter but it should be ok. and make sure to tweak ur airscrew id start at 3 turns out from lightly seated. If thats still not workin try dropin ur needle one position. i have a k&n with 5 uni air vents in my lid and im runin a 170 stock main jet, about 3.25 turns out on the air/fuel screw and 4th needle position which is one down from stock. It runs a lil rich but thats ok with me.

[cals400ex]

yeah, hmf's jetting specs are way off. that is too big. go get a keihin 152 or 155 main jet and that should get you pretty close. with a 165 in, you will probally have less power than you did when stock. what altitude are you at and what is the temp?

[sgtstadenko]

Not sure about the elevation I'm in mid missouri. Temp has been in the nineties.

[cals400ex]

if you don't feel like rejetting as the temp changes, i would put in the 155 so the bike is not too lean in the winter months. in the summer, a 152 may be better but both should make the bike run good.

I live up in the montains in arkansas and it is uausaly about 90 but it isn't rich in the mid to top it is in the bottom that it is rich i really don't feel like takin my carb off again cuz its not that bad.

[cals400ex]

we need to remember that when jetting we are dealing with throttle positions and not topend and lowend. the mainjet is being used if your at 3/4 to full throttle whether your in 1st or 5th gear. now if your saying its running good at full throttle but not at 1/4 to 3/4, then its your needle that needs adjusted.

yeh i know that but i just didn't feel like typing in throttle position.:rolleyes: anyways yeh i adjusted my needle but it runs great and doesn't stumble and only smokes a little when i start it up and give it a few revs.

[sgtstadenko]

Well I went 3 turns out on screw, 165 main, left clip alone. With lid off its about as close to perfect as I think I can get. No stumble, no bog, no smoke, and plug looks good, nice and tan. I may try a different filter and just vent the lid. I'm not sure if I'm comfortable with the lid completely off. The power increase is awesome though, It really suprised me.:D

i might have to tear mine apart and do that. I have a 165 that i bought just in case. I just might do that.