Mikuni Vacuum Fuel Pump Upgrade

By:Hammer

I told no_bmw_for_me I'd document my Mikuni fuel pump install. It is really so simple I just took a couple pics and I think they will tell the story. I wanted the suction line as short as possible, so chose the OE pump location as my new pump location. Made a suction line of 5/16" fuel hose. My bike has not had smog stuff for as long as I've owned it, so a vacuum source was as close as the fwd cylinder tap. I brought a line down from the fwd cylinder to the pump. I made up a long piece of fuel discharge line to go to a joint I found on the left side of the engine behind the tank. Joined upper and lower hoses there. I wanted a vibration resistant mount for the pump so I mushed the new pump into the flanges of the old mount. I had drilled a couple 3/16" holes in the mount for ty-raps to go thru. It's in there tight, but has give to absorb vibration.


There it is from the left side of the bike, looking up and back. Sorry about the pic quality, it seems kinda difficult to get a good pic from 12" away. The fuel line in front of the pump is the tank crossover, so you get the parts relationship.


Same thing, but this time from the right side looking left and to the rear. I just made a eweie with the hose rather than a bunch of brass fittings put together like seems to be used with the Facet electric.

It flows about 35L an hour, so if you can make your 950A drink more than that, you need a bigger fuel pump.
I got it here 'Bout 2/3rds the way down the page is the pump, a Mikuni DF52-21-D
Ask for it under the aftermarket part #, and get the lower price.
I got mine from Heeter's, where the link is. They use them often on snowmobiles, which tells me they flow lots more than we need.

They use them on ultralight aircraft, which gives me a lot of confidence in their reliability. The ultralight fliers aren't fond of engine stoppages.....
I did it cause of all the OE fuel pumps that have failed, and the amount of time I spend far from tow truck, pick-up, or aid. This is a more fail-safe system, and I can carry a rebuild kit with me, and overhaul it in under an hour.