Failed Fuel Pump?

[rdbul]

Had my Max spit and sputter suddenly and limped home a few weeks ago. Had Carb #2 steady flowing gas. Rebuilt carbs complete, found #2 carb float needle cone stepped; figured I had the issue sorted. Replaced rear valve cover gasket (leaking for years) and coolant and put it all back together to start. Gas never made it to the bowls.

I get one click from the fuel pump and that's all. Disconnected the lines from both sides and extended hoses to a portable gas tank: one click only and a little squirt of fuel. Hot wired 12V from battery to pump directly, the only way to get fuel to move is by connecting and disconnecting power over and over again, I get one pump per power placement. Pretty sure this means my fuel pump is gone. If so, I get that I could take it apart and try to place the diaphragms. I also found this cheapo replacement on amazon, they don't rate well. Is it worth playing with the diaphragm on my original pump/ is it a long-term fix (don't want to be fiddling with it again after I get stranded)? I guess I'm leaning towards the factory FK-13907-01-00. unless someone feels strongly otherwise or I'm looking at this all wrong.

Also, a question about function of the pump relay. The pump connector gets 12V when the ignition is switched on for a few seconds, then goes dead, then comes back when I hit the starter (I can't get to what it does when it runs because...well no pumpy) is this normal?

 

[rdbul]

Had a friend offer this explanation (posted for anyone searching for input on a similar situation in the future)(Thanks Again Mr. Morley!):

Your old pump may be dead or might need to be cleaned up and get any corrosion build up out. You can hit the side of the pump (not too hard) and see if that will help free up whatever is causing it to stick. The cheapy ebay may work and some have had ok luck with them. I still prefer stock ones.


The pump has multiple ways it finally gets it's power that overlap each other. This might be hard to follow but read it all and see if it makes sense for you.


When you first turn on the key AND have the engine kill switch in the RUN position you will have power to the pump for about 5 seconds. The relay has to sense a "tach signal" to show you are either cranking the engine over OR the engine is running. If there is no tach signal (AKA a crash or the engine isn't turning over) then the full time power will not be on after the 5 second delay. Each bump of the start button or cycle of the key restarts this 5 second cycle. It's always looking for the tach signal to go longer then the 5 seconds.


This is ALSO provided you have fuel in the tank (no low fuel light is on). If the fuel light is on then the power to the relay is cut off (when the reserve switch is in the ON position). This is done this way to provide you a "reserve" kill of sorts since there isn't an actual separate storage area in the tank or different fuel pickup location like on other bikes. You can bypass this portion of the checks/balances by putting the switch in the RES position (not the ON position which is the normal position). The RES position disregards the amount of fuel in the tank and allows power to the pump (again for only 5 seconds when first turning on the key or full time if there is a tach signal present).


To complicate this if the low fuel light is burned out then the pump will not work properly and will require the switch to be in the RES position to override and turn it back on regardless of the amount of fuel in the tank. When you are first starting the bike you should see both the low fuel AND the oil level red lights come on during cranking. That is for a simple test to make sure they are working.

 

[gentsvmax]

Yea, go to Amazon and get that Caltric, about 25 bucks! Got one maybe two year's ago for the same price and it's still working great.
Caltric is out of California, so far I have gotten clutch friction disk's and side cover gasket's from them and have had no issue's.
They have ridiculous low price's and are backed by Amazon, a starter clutch and gasket for 35 buck's?
Seem's like "too much sugar for a dime" as grandma used to say.

 

[Bill Seward]

I've got aftermarket eBay pumps in both Godzilla, and my Roadster. They work fine..