safe jetting for psi quads?

[jminor]

Whats everyone running for jets with modblasters on the 800's? I believe stock is 141's. Psi used to say to jet down to a 137? My numbers are being pulled from the top of my head, a trip to the shop would confirm this. When I say PSI used to say jet down, I bought my pipes off of Bruce this summer and he told me to run stock jets. The manual from 95 when they were made said to run much lower. I already know it's due to fuel quality today. What's everyone running?

[YAMMIEGOD 3:16]

ALOT OF THINGS IN QUESTION HERE. I RUN 135 MAINS IN MY 96 FOR ICE RACING UP TO 1000 F.T. SLED HAS SHIM KIT, HEADS CUT, PSI MAXXMODBLASTERS, etc. I ALSO RUN 100 OCTANE GAS. STOCK JETTING IS143.8 IN A 800. THE WHOLE ANSWER HERE COMES DOWN TO FUEL, AND FOR THAT REASON, JET RICH AND SLOWLY WORK YOUR WAY DOWN. IF YOU WANT TO LEAN ON THE JETTING, GET YOURSELF SOME RACE GAS, PRE MIX IT WITH PREM IF NOT, THE STOCK JETTING IS A GOOD STARTING POINT. BESIDES, YOUR 05 4 STROKE WILL BE YOUR EVERYDAY SLED ANYWAY RIGHT? ! 3:16 (tony)

[jminor]

Thanks Tony!Yes the 4 stroke will be the every daysled. For the Vmax I'm thinking of getting some race fuel that I ran in my bike during the summer and cutting it into premium fuel.A 5 gallon can is $140 CAD and I use about 1.5 liters per tank.Boy does that stuff STINK! Don't forget that I want to run long WOT distance so I was thinking of starting at 141's.



ALOT OF THINGS IN QUESTION HERE. I RUN 135 MAINS IN MY 96 FOR ICE RACING UP TO 1000 F.T. SLED HAS SHIM KIT, HEADS CUT, PSI MAXXMODBLASTERS, etc. I ALSO RUN 100 OCTANE GAS. STOCK JETTING IS143.8 IN A 800. THE WHOLE ANSWER HERE COMES DOWN TO FUEL, AND FOR THAT REASON, JET RICH AND SLOWLY WORK YOUR WAY DOWN. IF YOU WANT TO LEAN ON THE JETTING, GET YOURSELF SOME RACE GAS, PRE MIX IT WITH PREM IF NOT, THE STOCK JETTING IS A GOOD STARTING POINT. BESIDES, YOUR 05 4 STROKE WILL BE YOUR EVERYDAY SLED ANYWAY RIGHT? ! 3:16 (tony)

[YAMMIEGOD 3:16]

IF YOU GONNA MAKE ALOT OF WOT RUNS YOU MUST RUN SOME RACE GAS ESPECIALLY IN THE WINTER TIME. START AT 141.3,s RUN LIKE A 60/40 RACE GAS AND PUMP PREM. YOU SHOULD BE FINE. !! 3:16 (tony)

[WildMax]

What elevation are you? Guessing 4000' if you say stock at 141.

[jminor]

I'm not sure. How do I find out? I'm in the great lakes area (Niagara Falls) Maybe someone can help with info.



What elevation are you? Guessing 4000' if you say stock at 141.

[AL P]

your stock jets should be 143.8`s,
AL P

[YAMMIEGOD 3:16]

YOUR AT SEA LEVEL ! 3:16 (tony)

[WildMax]

I won't suggest what you should jet at but I have the same pipes and for the past 2000 miles have been running 135 mains versus 140 Yamaha spec - and still probably running richer than necessary. Keep in mind this is for a different elevation. This year, staying only 5000' and above, I will be changing to 130 mains versus 137.5 Yamaha spec and 127.5 PSI recommendation.

[jminor]

With your elevation in theory, would you be running fatter jets than I would because the air is leaner the higher you go above sea level?

[WildMax]

Not theory - science. Just the opposite, lean your jetting the higher you go.