Jetting catalog idea for those less experienced

[Wouldstalk]

My idea was to have everyone post up their bike, year model and make a nice compendium of jetting information that everyone can contribute to and see if it can be stickied in one of the maintenance or repair forums for future referencing for people trying to rejet their carbs for non stock exhaust and intake.

Ill start:

1982 Xj1100J
Mikuni BS-34III carb
4x1 Individual paper type air filters
Jets: Stock main 112.5; changed to 120
Stock pilot 47.5; changed to 50
Pvc extensions added between filter and carb to reduce air turbulence.
No changed to idle air/mixture screw

[TopCatGr58]

Hey Wouldstalk,

This could possibly be a good idea, but there are quite a few variables in configurations. Perhaps with enough participants we might get close to covering many/most of the combinations, but possibly not. This is why the Jetting Mod guide is listed with the caveat that it's just a GUIDE, and that folks will still need to test and monitor their plugs to see if further adjustments are needed. With that said, here are my specs.

81SH with 1179cc big bore,
81 carbs
Paper cone Indy filters/PVC mod
4-1 Mac exhaust
Mains upped from 110 to 117.5
Pilots upped from 42.5 to 45
Pilot Screws: ~2.5 turns out from seated

T.C.

PS, Wouldstalk....you forgot your exhaust type, OEM, Aftermarket?

[DGXSER]

TC is correct (of course) that even subtle differences like compression of the engine could effect the exact jetting, less subtle things like MFg of the exhaust will also effect it.

Anyway, I'll play along

81SH
81 carbs
Stock airbox with stock filter, Snorkel cut down to about 2",
What looks to be stock exhaust headers and 4-2 collectors with Jardine slipons.
Mains 110 all the way across
Pilots 42.5 Pilot air jets are 185
Pilot Screws: ~2 turns out from seated
Float level set at 23 +/-.5 MM.

[Wouldstalk]

My idea was to have everyone post up their bike, year model and make a nice compendium of jetting information that everyone can contribute to and see if it can be stickied in one of the maintenance or repair forums for future referencing for people trying to rejet their carbs for non stock exhaust and intake.

Ill start:

1982 Xj1100J
Mikuni BS-34III carb
4x1 Individual paper type air filters
Jets: Stock main 112.5; changed to 120
Stock pilot 47.5; changed to 50
Pvc extensions added between filter and carb to reduce air turbulence.
No changed to idle air/mixture screw

oh right, its Stock 4-2 exhaust

also ended up turning idle mixture an additional 1/2 turn out making it approximatly 3 turns from seated to get rid of some low end bog i had.

[Rasputin]

Every bike I have prefers different settings. Thing is there are so many variables from altitude, compression ratios, air intake, exhausts, year of bike and rider styles that it would be impossible to make sense of it. Basically this could be another "what oil do I use thread". If we had the participation of all members who ever joined it may make sense but as there are (for lack of knowing) about 70 active members I con not see the benefit. I can see this thread being a good thing with proper participation and a huge PITA if there is not enough. Personally I do not remember what jets are in any of my runners and I sure am not taking them off to find out.

[crazy steve]

... Thing is there are so many variables from altitude, compression ratios, air intake, exhausts, year of bike and rider styles that it would be impossible to make sense of it...

Add in engine/carb swaps, pod brand to that too...

Nice idea, but you wouldn't get any meaningful data that's any better than what we have now. Let's face it, you won't be going more than 2-3 jet sizes one way or the other in any case and the jets aren't that expensive.