Pulse Diaphragm Fuel Pump??

[Murphy625]

I thought I'd start a new topic for this because I'm betting I'm not the only one who seeks this info.

My 25 hp v-twin Kawasaki engine has one of those black plastic pulse diaphragm fuel pumps that operates off of vacuum. If I take off the discharge from that pump and turn the engine over, or just start it, can someone tell me how much pressure or volume is normal at idle speed or full speed? I found one video on youtube showing the flow as the starter turned the engine over and my fuel pump doesn't put out even near the same volume.

I was looking for specs on these, or at least a layman's description of its output volume /pressure.

thanks,

[bgsengine]

Just as a rule of thumb if it can pump a quart (32 Oz) a minute it's plenty so crank it for 15 seconds and that's about 8 Oz it could pump if it can make that , don't worry about pressure - most fuel pumps should not exceed 8 PSI as a general rule and if they can't produce enough pressure, they wont be producing a good flow either.

[Murphy625]

Just as a rule of thumb if it can pump a quart (32 Oz) a minute it's plenty so crank it for 15 seconds and that's about 8 Oz it could pump if it can make that , don't worry about pressure - most fuel pumps should not exceed 8 PSI as a general rule and if they can't produce enough pressure, they wont be producing a good flow either.

Well then the fuel pump must be my problem. When turning over the engine, my fuel pump would take about 15 seconds to fill a shot glass..

[bgsengine]

Just as a rule of thumb if it can pump a quart (32 Oz) a minute it's plenty so crank it for 15 seconds and that's about 8 Oz it could pump if it can make that , don't worry about pressure - most fuel pumps should not exceed 8 PSI as a general rule and if they can't produce enough pressure, they wont be producing a good flow either.

Well then the fuel pump must be my problem. When turning over the engine, my fuel pump would take about 15 seconds to fill a shot glass..

Probably the check valves are failing or they got bits of fuel line or debris stuck in them - sometimes flushing it out replace all fuel lines and before hooking up the line to the fuel tank, blow through it for a few seconds and then suck on it and if it "blocks up" when sucking on it the check valves are working, but if not, they are bad) - blowing through it can often force bits of debris out of the system - replace fuel lines because they rot out from inside with modern gas even if the outside of the lines look good - another rule of thumb for fuel lines- replace them every 3 years or so (much like the automotive recommendations for heater hoses) and you'll be much more trouble-free.