Superjet 701 Single Carb with Coffmans Pipe Jetting suggestions?

[B0000M]

hi, ive had a look through the other jetting threads and cant find anything of use so...


does anyone have a good idea of what i would need to change if anything jetting wise to run a coffmans sizzler pipe?

current setup is 6m6 701, standard exaust, high comp head, single carb

thanks

 

[ATS_Aaron]

I ran the same jets as for a b pipe with that setup.

Main 125
pilot 115
1.5 turns on both high and low
95 gram spring (stock?)
stock needle and seat

Aaron

 

[B0000M]

I ran the same jets as for a b pipe with that setup.

Main 125
pilot 115
1.5 turns on both high and low
95 gram spring (stock?)
stock needle and seat

Aaron

the other similar setup ive found is this

Brand = Mikuni
Model = Retail
Size = 46mm
Quantity = 1
Pilot Jet = 120
Main Jet = 150
Needle/Seat = 2.5
Spring = 80g
Pilot screw = 1-1/4
Main Screw = 1-1/2
- - - - - -
Gas Octane = 93
Altitude = Sea level
Main type of riding = Freeride
Would it pass the 10 second WOT test = YES!
Powerband = Bottom to midrange
Motor type/setup = 701 (61x cyl/61x case), mild cylinder porting, 180psi head, Boyson Pro series reeds, Factory "limited" B Pipe, stock F/A.




is there a way to tell how many g spring i currently have?


and how do you measure pop off pressure?

 

[ryan]

going to be hard to figure that one out. 6m6 reeds are so small. most of the jetting you are looking at are for 61x cases. i did a 6m6 701 years ago. i have to look at what i jetted it to. was way off compaired to a 61x 701.

 

[kevbo]

I have tuned that exact setup, heres what I learned. The 6M6 case will tend to run richer than a 61x case for a given carb tune. A 120-125 pilot with a 65G spring and stock 1.5 needle should be rich enough for the low speed circuit. I would not use anything smaller than a 140 high speed jet and tune with the top screw. Start 3 turns out and lean in. Power should rise with each 1/2 turn in until it hesitates when you hit the gas (while riding), then back up. I your screw ends up over 1.5 turns out then install a bigger jet and retune. The bottom screw can be set out of the water with the engine idling.

 

[ryan]

i looked i cant find my jetting i ran for that set up. (i have them all written down) kevbo is right i would try he he is suggesting.

 

[orangefinger]

coffmans recommended 2,0 N/S ... I always ran it same as mentioned above with 1,5 N/S

 

[kevbo]

A 1.5 should be fine with a stock cylinder. If a 2.0 is used make sure to install at least a 95G spring, a 115G will clean up excessive sputtering around half throttle.

 

[B0000M]

thanks guys! the answers have come in whist i was away for the weekend,

i pulled my carb apart and found i had a

120 pilot
145 main
1.5 needle
95g spring

ive put the coffmans pipe on, and am now running 1.5 turns on the high screw and 1 3/4 on the low.

ive noticed at low revs it runs a but rough, but smoothes out as the revs get up.

i keep reading people's pop off pressures, and reccommendations of pop off pressures around 20psi, how do i measure my current pop off pressure?