630 Fuel Pump Leak

I got home after being gone all week and found a puddle under my 630.
The pool was located directly below the fuel pump corner of the tank.



At first I was afraid the tank had a split. So I drained the tank and pulled it off. Turns out the leak was at the bottom of the fuel pump flange. I pulled the fuel pump and found the white substance between the fuel pump gasket and the gas tank. Cleaned it all up, reassembled, and so far no leaks.






I’m guessing that this stuff is some sort of thread locker that was spilled during assembly. Anyway I just figured I’d share in case it happens to someone else.

I had a leak in the same spot that didn't show up until I let the bike get really hot sitting at idle while doing some i-beat tuning. Dealer had another bike he had just gotten in so we swapped tanks real quick and no leaks since. He pulled the pump out of my original tank and found a small radial ridge in the tank plastic, smoothed it out, reassembled and no more leaks.

Glad you got it sorted out!

Thanks.
I typically create a post using Word, and then copy/paste to the forum. I'm not sure why it didn't work this time. Anyway, it's edited now.

I just dropped my Sm630 off at Bill's yesterday for a leak around the fuel pump. Bad that it was dripping right on the exhaust header.

Yeah, that might be bad.

Count me in as another leaky tank. I was getting the bike ready for my morning commute when I smelled gas and noticed a wet header pipe. Sure enough, leak at the pump. Suppose I'll drive the truck to work and take it apart for a fix.

edit: Well, I took it all apart, cleaned it all, and reassembled.....three times and still it leaks. I can't see any cracks in the tank or the pump flange, and the rubber ring looks good, so I figure the tank may be warped. I guess it's a call to the dealer tomorrow.

So I'm getting a new tank and panels. A couple inserts in the tank had spun when the bike was still at the dealership, so the panels are a little messed up, but the dealer is cool enough to swap those out as well. Looks to me like mounting surface on the tank is warped, since I couldn't seem to get a good seal around the flange.

Could it be just a bad tank mold, or is it the crap ethanol fuel that warps the plastic? I know a bunch of Ducati guys had problems with the Monster tanks due to ethanol, such that a recall was issued. Hoping this new tank solves the problem.

The white substance is mostly likely fuel residue. This modern (reads: crappy) gas evaporates almost instantly and leaves a whitish powder behind. Will plug jets something horrible. If that doesn't get you algae will, it grows in the water that gets absorbed by the alcohol. Why do we have to deal with this BS????

As to the warped flange, dunno about that. I will suggest a fuel staiblizer though, startron, amsoil powersports treatment, or even just good ol' stabil. Put something in there though, you're getting bad gas in your fuel system. It only takes a couple of weeks of sitting to give us trouble. Not as troublesome with FI, worse for carbs. Can still create big problems though.

Bill found on mine that there was a weal spot in the tank where the fuel pump mounts and when the tank became pressurized at all it would leak. New tank on the way for me.

Looks like I'm the next lucky owner with a leak at the fuel pump on my 630.

I'll be pulling it apart to take a closer look in the morning. Hopefully it just needs to be cleaned up and properly tightened.

Does anyone know the torque specs for the bolts on the pump? I'm kind of hoping that they are loose like the bolts for the ignition key were (I lost one and came close on the other).

Torque specs are useless in this application IMO. The metal ring fastens flat against the tank surface so it can only seal/compress the rubber ring to a certain point. I'll look up the values in the shop manual when I get a chance.

Is the valve in the vent tubing a one way? I wonder if the tanks are building up pressure in this hot weather and causing the issue on a bad run of tanks?

Maybe so. After I emptied the tank, I held it up to the light and you could see major thicknes variation. The back end of the tank was VERY thin.

Ok, mine is leaking also. Is the best solution to DIY or take to dealer for warranty work?

Paul

It's fairly simple to pull the fuel pump assembly to see why it's leaking. If it turns out to be a manufacturing defect, take it in for warranty repairs.

Or, if you don't mind being without the bike for a while, plus the hassle of dropping it off, then take it in and let the dealer earn his keep.

I would go the warranty route. My dealer (granted he's 500 miles away), ordered a replacement tank for me with the understanding that it would be drop shipped to my door and I'd do the swap work. Luckily I had the parts in short time, so I never tried to home fix it. If you do try to seal the rubber ring yourself, use Permatex Hylomar, it's the only silicone like sealer that will hold up to gas.

What year are your bikes and how many miles??

Not cool Husky.

Mine is an '11 with only about 200 miles at the time. Seemed like a vey poor tank mold. I also had some kind of white mess around the flange. Figured it was some sort of sealer or dope Husky may have put there in a failed attempt to remedy the situation. If so, then 100% poor QC.