717 fuel pump question

[ctys20]

Since I have both engines out of my boat I would like to test the fuel pump. Seadooparts.com is showing each engine has it's own fuel pump on the carb? I thought the pump was in the tank?

And if I buy a new carb will the pump already be on it?

Thanks,

 

[jhjesse]

Not sure what boat you have?
Some boats have the external fuel pumps and some have the fuel pump/diaphragm in the carb. From what you are saying most likely it inside the carb and will come with the new carbs. When you took the carbs off did you have a 1/4" line that went from the mag carb to the engine?

http://osdparts.com/index.php?main_...facturers_id=&pfrom=&pto=&dfrom=&dto=&x=0&y=0

 

[Sportster-2001-951C-Stock]

Since I have both engines out of my boat I would like to test the fuel pump. Seadooparts.com is showing each engine has it's own fuel pump on the carb? I thought the pump was in the tank?

And if I buy a new carb will the pump already be on it?

Thanks,

The dual engine boats have separate fuel pumps for each engine(two pumps/boat), the pump is not in the tank for any carbed engine and there were two configurations for dual engines, one of which the fuel pump is on the carburetor and the other has the fuel pumps divorced from the engine.

 

[ctys20]

Sorry I forgot to specify this is for a 98 sportster. I'm guessing the pumps are on the carburetor and if so are they mechanically driven from the engine? Thanks!

 

[Waterluvr]

Sorry I forgot to specify this is for a 98 sportster. I'm guessing the pumps are on the carburetor and if so are they mechanically driven from the engine? Thanks!

There is an impulse line connected to the Mag side of your carb on the right side, it's just a few inches long and you can follow it back to the lower case where it attaches.

 

[Sportster-2001-951C-Stock]

The fuel pumps are driven by crankcase pressure pulses, so there's a hose that is routed from the crankcase to the fuel pump to provide this back and forth pulse that moves the internal pump diaphragm, and there are two valves (plastic disks) inside that open and close as the diaphragm is pushed back and forth by the crankcase pressure pulses. I haven't looked into the technical library for your particular configuration(carb or divorced carb) but this guy wrote up a fuel pump test procedure that you might find helpful:

http://www.seadoosource.com/mikunitests.html

And concerning the rebuildable fuel pumps, there are a few things you should be aware of if you decide to install new valves for whatever reason, be careful not to poke holes through the rubber grommets, make sure this doesn't happen when you install the valve disks: