Sample Triple Mikuni Jettings

[Bruce Woolmore]

feedback from some references:

"I'm running 3 x 40PHH-S with 32mm chokes on a Harada inlet manifold, Option 76 Degree cam, larger valves, raised compression and some porting of the ( E88 ) head. Exhaust system starts at an Option manifold running into a full stainless twin-pipe up and over layout. On my current setup the Main Jets are 160s and the Air Corrector / Main Air Bleed are 210s. All other settings and sizes are stock for the 'S' model 40PHH"

The stock 44PHH Mikuni jetting for the L-series sixes ( as recommended by Nissan's tech staff ) sold as Sports Option parts was as follows:

MAIN VENTURI = 37mm

MAIN JET = 160

AIR CORRECTOR JET = 180

PILOT JET = 55

EMULSION TUBE ( "JET BLOCK" ) = 8

f your Emulsion Tubes are marked "OA" or "OB" on top then you would be well advised to seek out a set of six "8" types and install them instead. This will be a great help with driveability and part-throttle response. The OA and OB are best left to racers, and are not as good as the 8 for the street.

the Nismo kit (16010-E4620) defaults:

Main Jet 175

Air Jet 250

Pilot Jet 55

Venturi 37

Jet Block -??

the factory Mikuni America defaults for the L24/26/28

Main 150

Air Jet 200

Pilot Jet 57.5

Venturi 34

Jet Block OA

pump jet 40

[Bambikiller240]

Hi Bruce:

Good Information for those folks running Mikuni's!

Thanks for posting.

Carl (aka Bambikiller240)

Tech Articles Moderator

[Bruce Woolmore]

"The engine I have in car now is a L28 completely stock. ..

I am using the 44's and an electric fuel pump as fitted to the 73 and 74 USA Z. Mine is a 72."

Choke Tube: 34mm

Jet Block: OA

Air Jet: 180

Fuel Jet: 140

Pilot Jet: 57.5

Fuel pressure regulator set at 3.5 psi

"I finally added the regulator this summer and wish I had done it sooner. The engine runs much better and smoother. It is also now more sensitive to tuning changes. Especially the mixture

screw on each carb."

[Joez]

I have a set of Tripple Makunies on my 240Z and not sure what size they are. All I know is when I start the car it runs really rich, the fumes are so bad that my neighbors dog fanted, I mean the dog fell to the ground. When my neighbor took their dog out for a walk, I had just pulled the car out of the garage and started it up to let it warmup, now I know it has always had this problem, so I didn't drive it very much I'm still in the process of getting the framerails done, floorboards and fender wells replace or beefed up for that matter,..... Well anyway as I started up the car about five to 10 minutes had gone by and the neighbor was just passing the back end of my Z and the dog just paused for a minute of two and just fanted. The neighbor said that he could smell the fumes over 20+ yards away. I think my carbs need to be readjusted, what do you think? Long story made short I bought this car from brother in College Station, TX about 7 yrs ago and he did most of the mods to it, but then got married and has started a family and could no longer work on the car so he sold it to me to keep and fix up which I have been doing. My brother mentioned to me that he had bought these Tripple Makunies from a friend in College Station, came off a drag 240Z so he thinks that the jets are too big for the set up that I have. I think so toooo. Could you direct me on what to do? You assistance is greatly appreciated. Joez