Jetting specs that I have used

[OsideBill]

Which style BlackJacks? SBN or I-body?

[jbracing]

They are SBN silver.
May be asking too much on jetting,but it was a good help for sure.
Tks JB

[krispaintballz]

On pats ski I ran Novi Bloack bodies f-booster 130 pilots 180 mains 2.5 n/s with 115 gram spring.

This was a 1390 locked pvs with triples.

[orthotist]

What would jetting specs. be for ?

02 Gp1200R with D-plate, mixed fuel, ADA Head with 38CC Domes (alt. about 1000 feet), RIVA flame arrestors. Stock everything else!

Just not sure what jetting should be! Any help?

[OsideBill]

1.5 N&S 95 gr spring, 110 lows 120 highs. the altitude may require adjusting down a bit from the 1 turn out lows and 1.5 out on highs, but I would start there to begin with.

[ChucktownGPR]

I have 2000 gp1200r with stock carbs, Prok FA's, Free Flow, and D-Plate should i run:

115 Pilots
125 mains
1.5 n/s
80 gram spring

What is stock carb Jetting? Thanks again for all the help!

[testle]

On my 2000 GP1200R stock carbs:

95 pilots

117.5 mains

1.2 N/S

115 gr springs

[OsideBill]

I have 2000 gp1200r with stock carbs, Prok FA's, Free Flow, and D-Plate should i run:

115 Pilots
125 mains
1.5 n/s
80 gram spring

What is stock carb Jetting? Thanks again for all the help!

no run
110 pilots, 120 mains, 1.5 N&S 95 gram spring, accelerator removed . 1 turn out on lows 1-1/2 out on highs. it works and is published in countless threads.

[testle]

I thought he's asking for the factory jettings for the stock carbs, hence the answer

[1200Jet]

After reading this whole post I'm still unsure what specs to use on my soon to recieve TJ ported 1300, I'm running single pipe, stock carbs, power plenum, advent.

I'v narrowed it down to 115 pilot, 135 main but I'm still unsure whether to go 1.5 or 2.0 n/s and a 80 or 95 gram spring.

I previously ran my stock 1200 with 110/125 95 gram spring and 1.5 n/s and it was almost spot on but you had to slowly feed it to it out of the box or it just fissed and went nowhere. I first thought the pilots were to fat but if you give it full throttle off the line is this the mains coming in to play? I'm trying to get my head around the effect each component has on the mixture.

Mikuni have a chart that shows the pilots only having effect from 0 to 1/4 throttle.
The mains 3/4 to full
and in the whole midband area the n/s and spring/popoff pressure come in to play.

So if a 1.5 n/s was spot on for a 1200 should I go up to the 2.0 on a ported 1300 or do the larger pilot and main jets still have an effect on the midband area? Or is it just that the carb pres to fuel ratio work for both 1200 and 1300.

Spring pressure, determins when your n/s kicks in, is it set up to a pre determined pop off pressure or do you change the pop off pressure to suit your engine?

Knowledgeable answers only please

[OsideBill]

The simplest and best answer is always go up and start fat it is cheaper. 2.0 and black is what I would run.

[1200Jet]

Thanks Bill, I'v just read the Mikuni manual and all makes sense now.

[TwoStrokePotomac]

OsideBill- I'm a newbie but have a great project in front of me.

I have a 1200R Ported, R&D Heads 39dome, Riva Gas P/V, Riva F/A, Hot Rods Crank, Speedwerx Triples, TRD Waterbox, and M-16 Reeds but stock Carbs.

I don't want to put anymore in this ski and buy performance carbs so do you have a good carb configuration?

I am premix, have choke removed, and going to add primer kit and remove pump.

Whats a good configuration?

Thanks in advance for all the help!

[ryancoggo]

what you think i should run with 1200gpr tripple pipe with novi 48 carbs and external fuel pumps ,vf3 reeds 150 psi comp,freeflow exaust tube, r and d ecm ,flam arrestors ?

[orthotist]

OsideBill, you helped me out on my 1200GPR with the carb spettings and they turnned out well. Just want to change to a different ski and see what you suggest.

I have a 1996 701cc Superjet with milled head, ocean pro vortex flames arrestors, choke plates removed:

Can you give me some starting specs. to open up these oem carbs? I think they are 38 mikuni.