M7 fuel pump problem

[turbo4]

A buddy of mine has come home for the third time with a fuel pump issue, or at least that's what he is told. Each of the last three times he has rode the 06 M7 (no mods) has quit on him within only a few miles.

The plugs appeared dry, and we knew it wasn't getting fuel. We were able to get gas in the cylinders, but it would stop running in a few seconds.

On the first trip to the dealer they said it was a bad fuel pump. With a new one in, it did the same thing on the second trip, and the third time being a year later, surprise-- the same thing. The dealer is now saying maybe bad fuel?? We all fueled up at the same spot the first time it went bad.

Is this a common problem with the fuel pump.

 

[Mjunkie]

There are 3 "pick-ups" in the fuel tank that have a screen over them to filter the gas. If these screens get plugged, no fuel pump will pump fuel. The dealer should have spotted that if that is the problem, but that's something to check.
If you go to www.brownsleisureworld.com and click on snowmobile, then parts, then new, you can pull up the the schematics of the fuel pump assembly and see what I'm talking about, then check them out for yourself. That's what I'd check first.

 

[furthur]

Yeah, those three pickups have something called "smart valves". Not sure what they do, but sometimes they go closed and the only way to open is to reverse polarity on the fuel pump for a sec and pump backwards, then they usually work. If he has bad smartvalves, might do what you describe? Something to check, anyway. M sled fuel pumps seem pretty reliable, from what I've seen.

John

 

[mtn mike on boost]

even if its not the smart valves, sometimes the debris is in the pump.my m7 acted up years ago and the dealer ended up putting in a new fuel pump.

at the beginning of this season, the pump quit working.i found a new one on e- bay for $200. better than $360 dealer price.i did pull the pump out, put 12v to it and it was just plain locked up.then at the end of the first ride out with the new pump, it just died and wouldn't start.

back home, found the new fuel pump was locked up too?
then w/ the pump out of the tank, i switched polarity, and bingo!
so i drained the tank and cleaned it, as well as the pick up and smart valves.
too bad i wasn't smart enough to switch polarity on the last pump, because when i did, it is now operating fine.anyone in the market for a used pump?
it fits all m laydowns 6-1000cc and its only $125.pm me if interested....mm

 

[clodhopper]

The "smart valves" prevent air from entering the system if one of the pickups is uncovered like when the snowmobile rolls over (not that that ever happens) or the fuel gets low. It acts exactly like it does when the pump quits. I believe M7's only have two. Cat came out with a new design in about 06 or 07 I think.

 

[turbo4]

Thanks for the help guys.