94' Zr700

I have a 99 vmax 500 with about 4k miles. For some reason last year we had a problem with it pumping gas back into the oil tank, i posted on here and we figured it was fuel pump so i put in a vmax 600 fuel pump and same problem happened. Ive gone through 3 motors now and im currently starting to fix the sled again for the kids to drive around the yard. I have no clue where to start i believe it is the pump itself? I have another pump off a 94 vmax 500 that is the same part #?Any ideas on where to start? thanks

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02' Viper 700
99' Srx 700 powervalve
94' zr700 clutched, k&n filters, mikuni racing carbs with racing suspension **R.I.P**(Broken Tunnel, Bulkhead)
94' v-maz500
00' v-max500
00' Trail Boss 325 Atv
2 09' Sportsman 500 Atv- With Tracks

yamadad4

if i remember correctly, the water pump drives the oil pump? you may have an issue with the impellor ,the drive belt, or the connection between the two.

for your fuel bleeding back into the oil, check your breather lines from the oil tank. you may also consider a installing a check valve in the line.

94' Zr700

Yes it does i had replaced the belt last winter, i might have hooked something up wrong

__________________
02' Viper 700
99' Srx 700 powervalve
94' zr700 clutched, k&n filters, mikuni racing carbs with racing suspension **R.I.P**(Broken Tunnel, Bulkhead)
94' v-maz500
00' v-max500
00' Trail Boss 325 Atv
2 09' Sportsman 500 Atv- With Tracks

yamadad4

good place to start, make sure the flat pin is inserted correctly into the pump drive and work your way out from there. hoses attached correctly?