I've seen a lot of questions about jet kits on here lately, and it just so happens that I just finished painting, jetting, and overall rebuilding a '95 katana. I didn't get far into the motor, but just about everything else on the bike has been rebuilt.
Anyways, the bike is totally stock EXCEPT a full Yoshimira exhaust system, headers and can.
I purchased a factory pro jet kit, thinking that I would need it, and of course put the largest jets in (117.5) because, hey, it has a full system right?
Wrong. The top end was brilliant, it idled ok, but the midrange from 5-7000 RPM was totally dead. I couldn't lean it out enough, it was always too rich with any needle setting.
So I went to the 115 main jet settings, and again, great on top, idle was a bit lean (had fuel screws 4 turns out, still not rich enough), way too rich on the midrange.
Finally, I put everything stock back in it, 112.5 mains, stock needles, but a 35 idle jet (stock is 32.5). It now idles and runs great. There is a very, very slight dead spot around 6000 rpm, but I don't want to experiment any more with the aftermarket needles. I figured i'd put them up on Ebay or something, obviously my bike doesn't want a jet kit.
Anyways, I just thought i'd share. With aftermarket filters or something, maybe it does need a kit. But this particular bike, the exhaust apparently didn't lean it out enough to need bigger jets. I hope to post picks soon, the paint turned out great.
Thanks for all who offered advice.
Anyways, the bike is totally stock EXCEPT a full Yoshimira exhaust system, headers and can.
I purchased a factory pro jet kit, thinking that I would need it, and of course put the largest jets in (117.5) because, hey, it has a full system right?
Wrong. The top end was brilliant, it idled ok, but the midrange from 5-7000 RPM was totally dead. I couldn't lean it out enough, it was always too rich with any needle setting.
So I went to the 115 main jet settings, and again, great on top, idle was a bit lean (had fuel screws 4 turns out, still not rich enough), way too rich on the midrange.
Finally, I put everything stock back in it, 112.5 mains, stock needles, but a 35 idle jet (stock is 32.5). It now idles and runs great. There is a very, very slight dead spot around 6000 rpm, but I don't want to experiment any more with the aftermarket needles. I figured i'd put them up on Ebay or something, obviously my bike doesn't want a jet kit.
Anyways, I just thought i'd share. With aftermarket filters or something, maybe it does need a kit. But this particular bike, the exhaust apparently didn't lean it out enough to need bigger jets. I hope to post picks soon, the paint turned out great.
Thanks for all who offered advice.
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