external pumps vs carb mounted pumps??

Flash-FX

Flash-FX

No Square..No Round..FX-1
Location
South Jersey Shore
That looks sweet! I remember briefly seeing (in Daytona)a small pressure gauge on that fuel line exiting the tank. You're always coming up with cool ideas. So, I assume you are running blank plates on the pump side of the carbs with no pulse lines?
The big question is, does it improve on the lower speed metering adjustment? Like from idle thru 1/4 throttle? :question:

If it does...I'm all over it!
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
Flash-FX said:
That looks sweet! I remember briefly seeing (in Daytona)a small pressure gauge on that fuel line exiting the tank. You're always coming up with cool ideas. So, I assume you are running blank plates on the pump side of the carbs with no pulse lines?
The big question is, does it improve on the lower speed metering adjustment? Like from idle thru 1/4 throttle? :question:

If it does...I'm all over it!
Click to expand...
Yes to all your questions.

I used the Mikuni fuel pump block off plates from Jet-World.net part number 53-3330 for $11.69 each and a couple of brass primmer fittings part number 53-9921B for $1.85 each to plug the pulse nipple fittings in the case.

The 1/4-inch size flow control valve is also available from Jet-World part number 52-3122 for $34.40 it has a Viton ball check valve that works great in the return line for adjusting the fuel pressure. You can also use a .70 main jet in the return line but the fuel pressure will fluctuate slightly with voltage variations.

The fuel metering is way more accurate throughout the rpm range in any throttle position and you'll want to run higher pop-off pressures with your carbs.
 
Speedfreak

Speedfreak

Location
So. IL
Would the use of an electrical fuel pump also eliminate the use of a primer.

I know that properly adjusted carbs don't need a primer but I just don't like properly adjusted carbs... Or well I have never had them that adjusted. Plus I don't like the cranking waiting for the fuel to get there. I want 1 revolution and the ski to be idling.
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
I run a bulb primmer just for safety reasons, but it rarely gets used.

The fuel pressure is almost instantaneous from the second the switch is turned and no cranking is necessary to build up the fuel pressure as with mechanical style pumps.
 
Speedfreak

Speedfreak

Location
So. IL
Another question what does that weigh? Or I should ask it this way.. Which is lighter the electrical pump, wiring and switch or the 65 LPH external pump, mounting bracket, bolts and primer line.

I am trying to justify the cost with more than just better low speed metering.

I have 48 Full Specs so the metering isn't really a problem anyhow.
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
I had one of those five sided Mikuni fuel pumps and those a very heavy compared to this small electric pump, but with the combined total, they might be about the same.
 
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