Proper mounting location for a pulse fuel pump ??

[Andyman]

I added a Mikuni fuel pump to feed the Bing carb. and am not sure level or below carb. or tank.

ST400R with CCW400, Bing 54, Mikuni.

[james gerber]

Most say to keep it up high as you can,level with the fuel tank. I run mine down low close to the bottom, but only so i could keep the pulse line and fuel line
short as possible. (also used a thick heavy pulse line to keep it from collapsing in the heat)

[Andyman]

Thank you

[ARGOJIM]

Most say to keep it up high as you can,level with the fuel tank.

This may be so fuel does not fill crankase in the event of diaphragm failure.

[Andyman]

Pump

20190109_144414_resized.jpg

Here is what I ended up with, I went on a short test drive and seemed to work nicely until it started raining so I ran for cover (no top).

I can feel more power out of the 400 than before, I better check my chain condition, and it start's right up.

What do you think?

[dave phelps]

new carb Andy?? keep an eye on the plugs is all I can say, bet she scoots!!!!

[Andyman]

new carb Andy?? keep an eye on the plugs is all I can say, bet she scoots!!!!

Each run I pull plugs and look until I get it just right, I am use to from dirt bikes .

It is a Bing 54 36mm which came with big main and kept fouling right plug so I got a few steps smaller to lean it out.

[dave phelps]

Each run I pull plugs and look until I get it just right, I am use to from dirt bikes .

It is a Bing 54 36mm which came with big main and kept fouling right plug so I got a few steps smaller to lean it out.

I kinda figured you knew what to look for. LOL I always wondered why ultralights had bing carbs and never mikunis??

[Andyman]

I kinda figured you knew what to look for. LOL I always wondered why ultralights had bing carbs and never mikunis??

I will let you know if they belong in the air instead of the ground, haha. The owner of my Attex was into ultralight also so that's where this carb came from.

Early Maico bikes had them also.

[Andyman]

I was still getting some air in fuel line and noticed the clear VW style braided line I put on just so I could see the action wasn't sealing at well no matter what clamp I tried, so I put heavy rubber and moved pump closer to engine like James recommended at all seems good now.
My theory is the air was compressing some what and acting up the carb tune.

Either way thanks for all the input everyone.