Interesting situation...

[Bill Seward]

I have a fuel pump that clicks like a SOB, so I finally worked up the ambition to look inside for the famous wandering diaphragm. No luck, I guess my pump is just worn out at 130,000 miles.

Interestingly, I was testing the pump, and forgot to attach the 2 ground wires to the frame. Turning on the key, the tach went to 4000 rpm, motor not running.. I touched the grounds to the frame, and tach went back to zero.

Shortly after changing to the MOSFET voltage regulator, I noticed an oddity when starting from cold. The voltmeter would turn off just for an instant, and the tach would jump a few hundred rpm for the first quarter mile or so. Actual engine speed of course did not increase, just the tach reading.. I thought this may be ground related when I saw the tach go to 4000' today.

I very carefully sanded the ring connectors, the bolt, and the frame where they mounted..

Problem solved! Fuel pump is on the list of things to replace. I will keep an eye on that ground..unk:

 

[jfeagins]

Bill, were BOTH the rubber diaphragms were in place & free of any obstacles? ...and none of your carb floats were stuck open allowing fuel flow at the time of the persistent clicking? You may get an award for documenting the first of our pumps to have it's internal pressure switch malfunction...? I've not heard of one doing that before.

 

[Bill Seward]

The pump was as clean as a whistle inside.. No particles of anything, no rust, nothing. I think the little rubber valves may have stiffened up or otherwise stopped sealing. Any idea where to get them? I would replace them to see if that helps. By the way, the bike runs fine.. No visible or gas smell problems indicating a stuck float..

 

[jfeagins]

I don't know of a source to buy just the little diaphragms. I wish I did.

 

[Bill Seward]

Should a properly working fuel pump move a good strong stream of gas? I ran this pump into a jar, and it didn't seem to be moving a whole lot of gas, and it seemed almost sputtering the gas out of the line.. Internal leak in the valves in the pump? If so, I don't think it could build up much pressure, but supply enough gas to keep the bowls full.. Comments anyone??

 

[Traumahawk]

I wonder if anyone has ever taken a good pump and hooked it up to a gauge and said, it should hold X number of pounds of pressure.....or should pump X number of gallons a min?

 

[jfeagins]

Way, way back when I tested mine like that, it held a fairly steady stream of fuel. Sounds like your rubbers are suffering rigor mortis. That, or the pump motor itself is beginning to fail. When in doubt, change it out. It's better than being stranded away from home when it fails completely, don't you think?

 

[Bill Seward]

Looks like I'm off to "Fuel Pumps 'R' Us"...
Funny thing, My Roadstar has a fuel pump. Strange, as its a huge gas tank with a petcock. You'd figure the thing would gravity feed. I belong to a Roadstar forum, and a number of guys have tossed the fuel pump.. Some reported a gas starvation issue after a few miles of WOT, replacing the needle and seat with one from one of the big ATV's allowed more gas flow, negating the need for a pump.
I always carry a few feet of gas line in the Roadie just in case the pump poops out, I can get home gravity feed. I may just try to sub the Roadie pump in the Max to see what happens.

 

[Traumahawk]

How about this?

http://www.ebay.com/itm/291222183638?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

 

[scuff]

i believe 3lbs of pressure is all they produce but i know mine sends a steady stream but you can stop it with just a slight amount of pressure from your finger found this out when i didnt hook up my gas line after changing my jets, lol

 

[Dragmaxster]

i believe 3lbs of pressure is all they produce but i know mine sends a steady stream but you can stop it with just a slight amount of pressure from your finger found this out when i didnt hook up my gas line after changing my jets, lol

Ok then, well now you have made up for it and thank you for the info.