running one fuel pump

onebun · Post by **onebun** » Fri Nov 27, 2009 6:13 pm

can anyone offer any info on what type of single fuel pump they are running on there vmax?i have a dual output mikkuni with 1 pulse line and 1 intake line from the tank,my sled runs great if i load the carbs with fuel, disconnect the intake line from the tank,shut it off starts great when it starts to run out of fuel i just put the intake line back on for a few seconds till it starts going again and it runs good till it looses fuel again!if i leave it there it floods,gas in pipes and wet plugs.now the carbs where at the dealer neadle and seats where changed float hieght is correct,the fuel pump was rebuilt and moves fuel with ease,i am waiting on a new pump to try and swap it out. i was running both pulse lines "T" off into one and hooked up but changed it to one line.and i made sure i plugged the other line off good.and it still floods,if i suck on the pulse line i get no gas in my mouth and fuel comes out the outputs.any ideas?im thinking maybe i got the wrong fuel pump but i think it is off of a 81 srx thanks john

jefflanthier · Post by **jefflanthier** » Fri Nov 27, 2009 6:35 pm

i,m wondering if maybe a float has a hole in it ? Or the float pins in the carbs some times need a good cleaning, The pin holes in the floats get gummed up i use a piece of wire to kinda scrape them out . Just a thought! And make sure the fuel pump is put together correctly just in case there was a mistake made. good luck

Bob Vehring · Post by **Bob Vehring** » Fri Nov 27, 2009 7:39 pm

My guess would be a leaking needle and seat. With the float bowl off, you can put a hose on the inlet and blow gently, When you push the float up by hand, you can feel the air stop blowing threw if its sealing.
Haven't tried it on my VM, on my SRV which makes about 85 HP I run one pump with 39.5 carbs, have done it for years with no problems

sxr1000 · Post by **sxr1000** » Fri Nov 27, 2009 10:46 pm

I use a pump from a 95 vmax,your problem sounds like a hole in the diaphram.

onebun · Post by **onebun** » Fri Nov 27, 2009 11:11 pm

would the pump still move fuel if there was a hole?

onebun · Post by **onebun** » Fri Nov 27, 2009 11:12 pm

is that pump vmax 500 or 600 or are they the same?

sxr1000 · Post by **sxr1000** » Sat Nov 28, 2009 3:49 pm

500 and 600 are the same.

onebun · Post by **onebun** » Sat Nov 28, 2009 4:06 pm

thanks found that the power jet is dumping fuel in like crazy