Jetting specs that I have used

[Fercho]

1200 GPR single piper ported or not, Flame arrestors, Advent CDI Yam 84 Engine, No accelerator pump

Stock, Novi modified, Prok Atomizers or RPM modified (Stock Bore)

110 Pilots
120 Mains
1.5 N/s
95 Gram Spring

Buckshot modified stock carbs to 46MM Bore
130 Pilots
117.5 Main
2.3 n/s
95 Gram Spring

For a Triple Piper 1200 add 20 to the main jets.


1300 GPR single piper conversion (Ported), Flame arrestors, Advent CDI Yam 84 Engine, No accelerator pump

Stock, Novi modified, Prok Atomizers or RPM modified (Stock Bore)

115 Pilots
135 Mains
1.5 N/s
80 Gram Spring

BlackJack 48mm (SBN Core)
120 Pilots
100 Mains
2.0 N/S
80 Gram Springs
Drilled out restrictors with a 90 main jet in the return line to equalize fuel pressure


1300 GPR Triple Piper (Ported), Flame arrestors, Advent CDI Yam 61

Novi 48MM Carbs

120 Pilots
135 Mains
2.0 N/S
95 Gram Springs
Dual Check valves in the metering block
Dual springs on Throttle to prevent dribbling at idle
90 main jet in return line
(External Mikuni Pumps)

1400 GPR Single Piper Ported (87 Wiseco's)

BlackJack 48mm (SBN Core)
110 Pilots
110 Mains
2.5 N/S
80 Gram Springs
Drilled out restrictors with a 90 main jet in the return line to equalize fuel pressure


All of this jettings will apply to ski's with V-Force III Cages

[Fercho]

GP1300R Triple Jetting

1300R Conversion Lightly Ported
02/05 Entry prior to full porting ( Please note that the jetting for the TPP Ported 1300 that I posted above I ran at Mudbug and the ski was way rich, so that is my starting point and should pull strong)

48 Novis
115 Pilots
125 main
2.0 n/s
95 gram spring
1 1/8 turn out on the lows. 1 turn out on the highs
3 Mikuni External Pumps
200 Main Jet on Return line
Dual check valves on metering block
Pro-Tec intake manifold 93 Octane 32:1 fuel/oil ratio
155-160 Cranking PSI
Yam-61 Advent Curve

Jay's Ported 1200R Triple piper with Novi 48's and External pumps

115 Pilots
125 Mains
2.0 N/S
95 Gram Spring
130 Main Jet in Return Line
155 PSI Cranking Compression
Advent YAM 60 Curve

[RX951]

Jetting Specs GP1200R GP1300R

Great information to share Fernando !!!

I can't imagine the hours you have from all the testing to dial in each one !!

[RX951]

Fernando Buckshot Jetting GP1200R

Here are the jetting specs Fernando dialed in back in Feb 2002 for the GP1200R.
I currently run this reverse jetting on the Buckshot modded carbs on my 12R. It hits !

130 Pilots @ 1-3/8 turn
120 Mains @ 1-1/2 turn
2.3 N/S with a 95 gram spring
pop-off checked at 17 PSI.

[addicted]

Fercho,

Any specs on a 1200 with a dplate and stock airbox?

http://www.greenhulk.net/showthread.php?t=37158

Thanks,

Mike

[Fercho]

Try 100 pilots 120 mains 1.5 n/s 95 gram spring

[VOODOO]

Nando, what do you recommend for a 1300 with no to little porting, head, single pipe, stock carbs with F/A's and VF3.

[Fercho]

Bro I would go

115 Pilots
125-130 Mains
1.5 N/s
80 gram spring

[OsideBill]

Fercho I have a Lowell ported 1390 build in progress with 44 I body Black Jack conversion.

Art Recommends

110 lows 1 turn
150 highs start at 1.5 turns and tune down
2.5 N&S Black spring

Your thoughts on this please.

I am also building a 1300 rec ported motor and was considering running these on it and finding some 48's for the 1390 Art suggested only change the main to 145 if I run on the 1300

Thanks as always O'sideBill

[Fercho]

Bill I will give you some beter specs in about a week. I got some carbs in Razzbo's 1390 XLT and I blve I am running 115 pilots 1.5 n/s 80 gram spring and 145 main jets. The holeshot has a slight bog it I let it idle that can be cleared by adjusting the lows. We still have not adjusted the carbs and we are a 2 turns out.

On Lowell ported 1390 with SBM blackjacks I am running 110 pilots and 110 main 2.5 n/s 80 gram spring, restrictors drilled out with a 90 main jet in the return line. My best adjustment is 1 turn out in lows and highs

[spud]

We are looking forward to hearing your results Fercho.

Art set up my OEM modified to Black Jack 48's and jetted them:

110 pilots

2.5 N&S Black 80 gram springs

150 main jets

This is to go on a Lowell ported 1390

I don't know anything about Blackjacks so I am really interested

[Fercho]

Razzbo wil be working straight for 2 weeks so I will have to wait till then

[RX951]

I've ridden Razzbo's XLT1390 w/Blackjacks...all I can say is tha it HITS ! and its still running rich.

[Fercho]

We need to reinforce that pump tunnel somehow.!!!

I've ridden Razzbo's XLT1390 w/Blackjacks...all I can say is tha it HITS ! and its still running rich.

[spud]

Can we condense this information and make it a sticky, or just make it a stick in the how-to section? I plan to add when the BJ 48 "I" body conversions are dialed in.

Jetting that has worked very well for me with Fercho's recommendation:

Lowell ported 1300, single pipe, stock carbs, Prok F/A's, Advent Yam 59

115 pilots

2.0 N&S 95 G springs

135 mains

Lows 1 turn out

highs 1.5 turns out


Stock 1200 choke plates in:

110 pilots

1.5 N&S 95 G springs

120 mains

Lows 1 turn out
Highs 1.5 turns out

Stock 1200 choke plates removed

110 pilots

1.5 N&S 95 G springs

125 mains

Lows 1 turn out
Highs 1.5 turns out

Lowell Ported 1390 single pipe, Blackjack 48 I body carbs, Prok F/A's

Update: I ran the 1390 at Senator's Wash today. The ski ran great the water level was too low to get any runs in much over 1/4 mile. Temp was about 75 degrees

115 pilots

2.0 N&S Black springs

150 mains

low screws 1 turn out

High screws 1 1/2 turns out.

Ski was crisp and accellerated very hard. There might be additional fine tuning, but this works good.