Gas Leak/Starting Issues

[w00tbag]

Okay, first off, I'm sorry if this has been resolved before, but the only two threads on this subject I could find (one wasn't on this site) were never solved.

Anyway, I've got a 2000 Monster 750 dark with all newly changed fluids, new fuel filter (old one was pretty corroded inside), and the valves are, according to the dealer, freshly adjusted, as well as the carbs being cleaned twice in the one day before I bought it (it's a long story but I watched them do it so I know they're clean), and just a hair below 10k miles.

Overnight, and this happens only intermittently (twice a week, and I ride it every day) the thing leaks gas, pretty slowly, and I see it's coming from the carb overflow, which isn't that huge of a deal, I can fix gas leaks, but unfortunately every single night that it leaks, the following morning I have to let the starter spin for a good 10 seconds before it actually cranks. It's hard to explain, but it sounds to me as if something is sliding around and the starter finally grabs, after which it starts right up, no backfiring or hesitation out of the ordinary.

Oh, also the battery is brand new and is holding a charge perfectly, I had it checked.

Any suggestions as to what this is?

[crankmonster]

I am no expert on carbed bikes but it doesn't sound out of the ordenary to me.

Ride the bike and enjoy.

[swinger822000]

It sounds like the fuel pump is forcing the fuel to the carbs, even when the float would normaly click the pump off. Check the float cut off system it might be stuck in an empty carb position whick makes the pump keep filling. if that doenst change the issue post back and ill give you a few more ideas.

[w00tbag]

Thanks for the suggestion; I'll check it out when I have some time and means to actually work on the thing.

[MingThe Merciless]

Here's a possiblity you may not have considered: the tank vent is clogged. In which
case the mechanics are simple. When the bike sits over night, heat absorbed from
the tank expands the air inside. Unable to vent, it forces itself through the only
path left: the carb lines. When you're running the bike during the day, the periodic
opening/closing of the carb float needles allows this pressure to vent. If this is
the case, it's easy to check: Leave the gas cap open over night. If a leak still
appears, then you've eliminated that possibility, and you can then starting carb
yanking and disassembly. Personally, I tired of that chore years ago, and have duly
warned my M750 not to exhibit such behavior. So far she's listened.

[swinger822000]

hey i just experienced this yesterday. but slightly different. right after i filled up my tank to capacity i parked it for a few minutes to grab a drink. and when i came back out, fuel was pouring out of the emmisions box, and i popped the tank to releave the pressure and gas was coming out of the breather pretty hard then the bike was extremely hard to start and keep running. seemed the temp rose in the tank and all the gas expanded. so i would try this last post, seems very reasonable.

[w00tbag]

Ming, you're a savior. I finally got some time at home and left the thing sit overnight with the cap open for a couple nights and it didn't leak at all. Got some help from my friend who happens to be much more mechanically inclined than me, and it was indeed the tank vent. Thank you for the suggestion! Hopefully this isn't an illusionary fix due to the erratic nature of the problem, hee hee.