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X2M
08-12-2005, 02:48 PM
We were out at the lake last night and had a great time as usual. Headed back to the launch as the sun was going down. My husband dropped me off at the dock to get the trailer. While he was waiting for me to come down with the trailer, he said the boat coughed a bit and then died. He smelled a little gas too. He tried to re-start it and nothing. We still had 1/4+ in the tank, but it has been pretty hot here for a while. So he thought it might be vapor lock. He unscrewed the gas cap and then pumped the throttle a bit and it started. But he said it didn't fire right up like normal.

What do you guys think? Was it vapor lock? Is the fuel pump going out? We have a 2005 X2 with the MCX engine. And ideas will be appreciated. :)

rick s.
08-12-2005, 04:37 PM
I was out on another brand boat a couple of years ago. Wakeboarding then stopped to pick up the boarder. Boat wouldn't start afterwards. Cranked and cranked. Out of despairation (and not having anything else to do) I opened the gas cap and the boat started right up. I suspect vapor lock, but not really sure.

This was "the boat from h***" for a couple of years, but it finally got straightened out.

erkoehler
08-12-2005, 04:39 PM
similar situation, but I had an extremely full gas tank at the time.

Workin' 4 Toys
08-12-2005, 04:40 PM
I doubt it, but you have me puzzled.

bcampbe7
08-12-2005, 04:42 PM
Does/can vapor lock occur with EFI? I thought it was a carb issue.

MYMC
08-12-2005, 05:31 PM
How much fuel was on board? Did you look in the tank to know for sure.

X2M
08-12-2005, 05:33 PM
I'm pretty sure he checked the level in the tank. The gas gage read over 1/4 of a tank. We have had it lower than that before and no problems.

MichaelsPSP
08-12-2005, 05:52 PM
I had a similar problem with my 2005 x-2 mcx 3 days after delivery. The dealer changed fuel pumps. I went back out and it happened again - same day. They tested the fuel pump at the shop and said it was definetly bad. They suggested not to let the tank get below 1/4. The dealer thinks the pump is too high and not picking up fuel. BTW - the dealers owner drove 4 hours (one way) on a saturday of july 4th weekend to change the fuel pump. my hats off to liquid sports specialist,in NJ.

André
08-12-2005, 05:59 PM
MichaelsPSP
That was amazing of your dealer to do that.Foel pumps in the newer boats seems to be very fragile...
Oh,Welcome to the board!

Kevin 89MC
08-12-2005, 06:02 PM
Vapor Lock can definitely happen to injected engines. I have a car that it does happen to in certain circumstances. Carb'd engines tend to be more suseptible to it though. You can try wrapping the fuel line with some insulation. Also open up the engine box and squirt a small amount of water on the line (depending on where it's located), or just wait it out. A bad fuel pump can have similar symptoms, or allow vapor lock to occur easier if it's not keeping up good pressure.
Good luck,
Kevin

Engine Nut
08-12-2005, 06:33 PM
We were out at the lake last night and had a great time as usual. Headed back to the launch as the sun was going down. My husband dropped me off at the dock to get the trailer. While he was waiting for me to come down with the trailer, he said the boat coughed a bit and then died. He smelled a little gas too. He tried to re-start it and nothing. We still had 1/4+ in the tank, but it has been pretty hot here for a while. So he thought it might be vapor lock. He unscrewed the gas cap and then pumped the throttle a bit and it started. But he said it didn't fire right up like normal.

What do you guys think? Was it vapor lock? Is the fuel pump going out? We have a 2005 X2 with the MCX engine. And ideas will be appreciated. :)

Doesn't sound like vapor lock. First, that boat has pump-in-tank which significantly reduces the possibility of vapor lock. With pump in tank, the fuel in the fuel line between the pump and engine is under pressure which raises the termperature at which the fuel vaporizes.

Second, vapor lock does not generally occur on an engine while it is running. It most often occurs when the engine has been shut off after a hard run and sits for 15 minutes or so soaking uop the heat given off by the engine.

I suspect you may be experiencing a fuel pump problem.

Engine Nut

MYMC
08-12-2005, 06:35 PM
Okay, the filter only works below a 1/2 tank. I dont know if the boat has enough hours to justify a filter change but that would be where I would start. It sounds as if the pump got hot...but I don't know if that is due to the filter or the fuel level.

Remember: The fuel in you tank is what cools the fuel pump. This is the same as in your car. During the 80s and 90s GM used to tell you to never let the tank go below 1/4 tank. Good advice...for these late model boats as well.

X2M
08-12-2005, 06:41 PM
So your advice would be to check the fuel filter first. Is changing the fuel filter something that we can do or do we have to make an appointment with the dealer?

The boat has around 50-60 hours on it. Would that justify a change?

X2M
08-13-2005, 11:55 PM
Can anyone tell me where the fuel filter is on the MCX engine? Is it easy to get to?

Workin' 4 Toys
08-14-2005, 12:02 AM
Quote right from the Oper. and maint manual: Because the lines on late model Mastercraft boats are pressurized, they can be disconnected and/or removed by using specialized tools that are not available to the public.

I am not sure, but I would think the same rule applies for the filter. I have not looked for mine, and there are not specs for it in the book, bascially other than what I just mentioned.

X2M
08-14-2005, 12:04 AM
Well poo, that doesn't help me much. Thanks for the info anyway. :)

Workin' 4 Toys
08-14-2005, 12:08 AM
Well poo, that doesn't help me much. Thanks for the info anyway. :)
I would go look at it, but it still 100 miles from me with the brakes locked up on the trailer. I wish I could be of more help.

Workin' 4 Toys
08-14-2005, 12:16 AM
Reading further in the book, it also states in the "General preparation" section for winterizing... Note item number 4, it is written exactly that way in the book.
You need the following:
Stabil,
Oil,
oil filter,
Fuel Filter (if equipped)
low tack tape,
etc.,etc.,....

bigmac
08-14-2005, 12:45 AM
"Vapor lock" doesn't happen in a pressurized fuel system with in-tank pump. It was not uncommon is the days of carburetted engines if it was hot outside and the engine was hot - in those situations it was possible for the vapor pressure of the fuel to go higher than ambient air pressure and stop fuel flow, but in a pressurized fuel system there's virtually no way that could happen.

More likely some other problem with fuel flow - fuel filter, fuel pump, ECM...one guy here on TTC found a similar problem to be due to a loose battery connection causing ECM errors.

I believe the fuel filter is at the pump in the tank.

X2M
08-14-2005, 08:58 PM
Well, we went out this morning and skied and wakeboarded for 3-4 hours. No problems at all. Fired right up at the launch and ran great the whole time.

If the fuel pump is bad doesn't that mean that the boat won't run, it starts and then dies? Does a bad fuel filter affect it the same way? Or is that a hit and miss thing?

Workin' 4 Toys
08-14-2005, 11:35 PM
Well, we went out this morning and skied and wakeboarded for 3-4 hours. No problems at all. Fired right up at the launch and ran great the whole time.

If the fuel pump is bad doesn't that mean that the boat won't run, it starts and then dies? Does a bad fuel filter affect it the same way? Or is that a hit and miss thing?
On a GM EFI vehicle, we had a fuel pump go out. We were able to hit the fuel tank hard several times to get it back on the road and it drove another 300 miles or so then nothing, it just flat out stopped, repalced the pump, and on the road again. They are known to just stop. But they on occasion work tempermentaly. I give this example because I believe they are the same or very similar pumps.
A filter could possibly give you similar results. If it were me, I'd go with a new fuel filter if you can find it. Before you cause excess strain on your pump and fry that.

erkoehler
08-15-2005, 12:12 AM
Filters are cheap, I had to replace one this year. 10 minute job or less.

AirJunky
08-15-2005, 12:31 AM
I have the 350 TBI in my 94. Last summer I'd have a hot start problem after we'd just cruise around at low speed on a hot day. It would be running fine, I'd stop the boat & a few minutes later go to start it. It would turn over fine, and I could pull the spark arrestor & see fuel shooting in the EFI unit. I replaced the fuel filter (just follow the steel fuel lines from the EFI unit to the metal inline canister).
I looked around for info on vapor lock & read that it doesn't happen on EFI boats. But the way mine was acting, it totally sounded like it. I had the fuel pressure tested, fine. Replaced the fuel filter, fine. Replaced the water separator.... still had the same problems. So I found the recommended fix was a fuel line insulation kit. It's about 5' of black tubing. I cut it to size & installed it over every section of fuel line from the EFI back to tank. I haven't had the problem since.
I'm not saying it's fixed, but I haven't had even one hard start situation since doing this.

jimmer2880
08-15-2005, 08:22 AM
I have the 350 TBI in my 94. Last summer I'd have a hot start problem after we'd just cruise around at low speed on a hot day. It would be running fine, I'd stop the boat & a few minutes later go to start it. It would turn over fine, and I could pull the spark arrestor & see fuel shooting in the EFI unit. I replaced the fuel filter (just follow the steel fuel lines from the EFI unit to the metal inline canister).
I looked around for info on vapor lock & read that it doesn't happen on EFI boats. But the way mine was acting, it totally sounded like it. I had the fuel pressure tested, fine. Replaced the fuel filter, fine. Replaced the water separator.... still had the same problems. So I found the recommended fix was a fuel line insulation kit. It's about 5' of black tubing. I cut it to size & installed it over every section of fuel line from the EFI back to tank. I haven't had the problem since.
I'm not saying it's fixed, but I haven't had even one hard start situation since doing this.

Very interesting.

For what it's worth - MC is now saying that a filter should be placed before the pump & the one after the pump (hard steel line) can be removed completely (of course, a new fuel line will need to be made). I am in the process of doing exactly that on my '95 after burning up 2 fuel pumps in 400 hours due to crap getting caught in the in-let screen of our pumps.

Of course, this doesn't apply to the newer boats with in-tank pumps like x2, etc.

MYMC
08-15-2005, 09:46 AM
The fuel filter is located in the tank on the "foot" of the fuel pump, and should be replaced at the first sign of pump issues. You cannot "see" if it clogged as it is a 10 micron filter and cloggs easily.

peason
08-15-2005, 11:09 AM
Filters are cheap, I had to replace one this year. 10 minute job or less.

Erik, I have not changed my fuel filter on my 2002, is your pump and filter in the tank on your boat? I think the newer boats with the in-tank pumps and filters are harder to change.

With this being said, can a do it your selfer - change the filter on the newer style pumps? or is it best to have the dealer do it?

MYMC
08-15-2005, 11:17 AM
Unless you are very mechanical and have all the needed tools I would have the dealer perform this service...fuel leaks and boats don't go well together.

X2M
08-15-2005, 01:24 PM
What would you consider "very mechanical"? We do all of the winterizing and de-winterizing ourselves and over the years with our other boats we have fixed and replaced several parts. And what are the tools needed for this job? I swear my garage looks like a Kragens. We probably have every tool ever made in there. ;)

I will put a call into the dealer. I know I won't be able to get an appointment for 2-4 weeks to get this worked on. :( Is the fuel pump/fuel filter covered under warranty on new boats?

gr8smiles
08-15-2005, 01:39 PM
I followed MYMC's advice and replaced my filter on my new x-star at 75 hours...it would stall and sputter below 1/2 tank...changing it was a b**ch....I am pretty mechanical, but still a lot of screws...if you do change it yourself, don't do it when the tank is full of gas....kinda gets you a tad wet....it took about an hour...runs great now...105 hours

MYMC
08-15-2005, 02:41 PM
The fuel pump is covered by the mechanical warranty the filter is considered a wear item...but talk to your dealer he may be able to cover it.