|
|
Post by katt on Jan 24, 2019 9:09:55 GMT -5
I currently have stock #97.5 main jet installed and #22.5 idle jet on 26mm Mikuni carb
Have been running QMB139 with 80cc BBK on #110 jet in the past, had a zero resistance filter then
Even QMJ157 24mm carb comes with 100 or 105 jet size, how come this one has such a small jet?
Going to keep air box for this scooter, 125cc what main jet size you recommend, i have #100, #105, #108, #110 available.
|
|
|
|
Post by katt on Jan 25, 2019 10:03:27 GMT -5
I guess not one is familiar with this engine so no answers.
Its 125 cubic centimeters that needs to be filled up fuel/air mixture so jetting is identical to 152QMI besides the fact i got 26mm venturi carb.
Alternatively i could go as i did with GY6 just try all jets from #120 down and see if it overflow the engine on WOT then i go size down until i get to one that does not overflow anymore, then i monitor the spark plug to fine tune it.
|
|
|
|
Post by harleyracer59 on Jan 27, 2019 22:38:05 GMT -5
the jet is so small so Yamaha can be in epa compliance. I put a pipe on one of these vinos and it came with a jet a variator and an exhaust pipe. I believe the new jet was 110-115? it was a year ago so its kinda fuzzy. that package woke that scooter up!! like night and day. ill ask my customer what manufacture it was so we can figure out the jet number was exactly. I remember it being like a 10-15# different. I wasn't sure how it was gonna work with that big of a jump in jetting. it actually got out of its own way. as before it wasn't very exciting.
|
|
|
|
Post by gsx600racer on Jan 27, 2019 23:02:19 GMT -5
With the emissions crap that's installed, Id leave the jetting alone.  |
|
|
|
Post by katt on Jan 28, 2019 8:19:30 GMT -5
the jet is so small so Yamaha can be in epa compliance. I put a pipe on one of these vinos and it came with a jet a variator and an exhaust pipe. I believe the new jet was 110-115? it was a year ago so its kinda fuzzy. that package woke that scooter up!! like night and day. ill ask my customer what manufacture it was so we can figure out the jet number was exactly. I remember it being like a 10-15# different. I wasn't sure how it was gonna work with that big of a jump in jetting. it actually got out of its own way. as before it wasn't very exciting. This sounds interesting i used 105 jet at moment.
My point with the jet to avoid leaning it out i want to be on the safe side, i know sooth from too rich could clog the catalytic converter, but if i monitor spark plug it should be able to find a proper mixture.
|
|
|
|
Post by ryan_ott on Jan 28, 2019 18:48:30 GMT -5
Mikuni jets are label for flow, Keihin (PWK) jets are labeled by size, hope this adds to the confusion.
|
|
|
|
Post by benji on Jan 28, 2019 18:52:20 GMT -5
|
|
|
|
Post by katt on Jan 29, 2019 19:59:40 GMT -5
Currently have Keihin #105 installed and seems to be faster accelerating, but according to table stock was Keihin #108 so i actually leaned it out a bit.
I also used whole different carb from donor bike, could be that.
Anyway what size would you suggest to use for improved performance, about to receive new air filter and it will let even more air in, i thinking keihin #115?
|
|
|
|
Post by katt on Feb 7, 2019 11:20:39 GMT -5
I went with Keihin #125 main will let you know how it turned out once finish testing.
|
|
|
|
Post by katt on Feb 7, 2019 20:12:07 GMT -5
Got little sluggish at WOT and got slight overflow, power loss with #125 switched to #120 little better.
Video uploading now
|
|
|
|
Post by CrankingWithCG on Oct 13, 2020 0:39:43 GMT -5
Weird thing i noticed with my vino when i had it, i could use standard GY6 type Keihin mains, but i had to use Mikuni VM22 style pilots i believe? What did you finally settle on for jetting there?
|
|
