View Full Version : Fuel Spillage, Port and Starboard vents

06-27-2009, 09:26 PM
Just purchased a new 2008 X-35 in May. Boat was at the dealership having two new tower speakers installed and first oil change. Went to pick-up today and immediately smelled strong fuel odor in outdoor parking area. Upon closer inspection, i just about stroked-out when i saw the x-35 decals completely delaminated and bubbled due to leaking fuel. This was the port side. Starboard side was damaged but not as bad. Both still have to be replaced. Tanks were full but not over-filled after last lake visit. No where in the Mastercraft owners manual is there any caution about fuel filling levels, save for not allowing tank to be depleted below 1/4 tank due to fuel pump issue.

Have seen multiple posts on failing fuel pumps, and have seen a recall on Maristar 280 and x-80's from a fuel tank vent line severed by flawed floor panel design. But nothing on overboard venting and severe decal damage. Disappointed dealer allowed this to happen on their watch--quite certain i would have noticed immediately. Temps were near 100 this week, so gas expansion an obvious culprit. Since the fuel lines are pressurized, any one know if there is a check valve that unseats to vent at certain pressures? We're also experiencing erratic fuel gauge readings. Manual says most accurate while level and still; we get most accurate readings at full throttle under seemingly fully pressurized lines. Have confirmed this after refueling at marina and notating gallons filled.

If anyone can enlighten on similar experience, this would be greatly appreciated!! Dealer will be replacing the decals. i want to correct the true source of the matter. If it simply involves changing fueling techniques and underfilling, have read others having to do this on Mastercraft's and other boats as well.

06-27-2009, 09:56 PM
I've had that happen too, if I'm not careful about fuel level and high heat. The fuel tank and lines aren't pressurized. Like virtually all pleasure boats, the tank is vented to the air as required by USCG. The vent is in the filler cap on many of the MC's. Maybe yours has separate external vents (my old I/O did) but the concept is the same - the tank is open to the air.

Doesn't have anything to do with your fuel gauge readings.

Nice goodwill gesture by the dealer to replace the decals for you. Just an opinion, but had that happened to me, I would have felt it was my responsibility.

07-10-2009, 08:35 AM
Reportedly, this air/fuel separator works pretty well for this type of heat expansion vent overflow. Not sure of its applicability to boats (like mine) where the vent line is integral to the filler tube. Also not sure, on boats with two filler caps (one on each side), if both caps have vent lines. If one has two vents, I think you'd need two of these.



There's a step-by-step installation guide here (http://www.themalibucrew.com/forums/index.php?autocom=tutorials&article=42).

07-15-2009, 10:32 AM
There is an issue with the 2009 boats venting gas. It may also apply to the 2008 models. My dealer had a service bulletin that addressed the issue when my X-45 vented a bunch of gas while in storage.

east tx skier
07-15-2009, 10:39 AM
Had it happen on my new to me boat. Fuel vents to the transom. Cover got a little damp with fuel, but otherwise, no damage to transom decals. Heat and expansion and topping off is the culprit as you mentioned. From MC's end, like BigMac said, it's a requirement under the coast guard reg's. Placement is obviously an issue, but there are not too many spots on the boat where there aren't decals; so it may be a no win situation. Probably worth a mention in the owner's manual as you said, but the solution is simply to not top off. Sorry it happened, but glad your dealer hooked you up.