View Full Version : Engine would not start

07-05-2007, 09:03 AM
I know there has been a post about the engine not starting. I went to the lake and was having a blast. Skiing, wakeboarding, having fun on the boat. We found a nice cove to have lunch. The radio was playing and the temp was 115 degrees on the water. Yes I live in Las Vegas. After about 30 or 40 min, we went to continue the fun. Went to start the boat and it had a very rough idle. Shut the engine down and tried to restart it. The engine would not start. The motor was turning but nothing else happened. After about 20 min of trying the engine, we finally flagged someone down. When this person came to our aid, I had asked my wife to try to start the engine again. The engine started right up. Could these engine vapor lock? Because of it being so hot, Should have I lifted the engine cover to cool off a little? After the engine started, we found our friends and could not duplicate the problem. Has anybody experience this problem.
Also, I saw another Moomba on the water on this 4th of July afternoon. It was Red and Black. If you are a member of this sight, I just wanted to say Hello.

07-06-2007, 10:48 AM

Sorry to hear of your problems. See the link below, specifically, the second post.


I think lifting the engine cover or running the blower would have been a good idea.

Hope that helps.


07-06-2007, 10:56 AM
I had talked to the dealer. They told me that it was vapor locked. The Lake was very hot that day. Indmar is aware of the problem and is sending out a new type of fuel pump for the boat. They said that this would eliminate the vapor lock.

07-06-2007, 11:48 AM
Wonder if this applies to the 2006's? Is this a recall type issue then that they are swapping out the fuel pumps at no cost to the owner?


Engine Nut
07-06-2007, 04:19 PM
Wonder if this applies to the 2006's? Is this a recall type issue then that they are swapping out the fuel pumps at no cost to the owner?


This a message I posted a couple of weeks ago in the Service ans Repair area. The information is still valid. We are not swapping out fuel pumps on engines.

A little clarification. The issue we have been seeing that is presumed to vapor lock is a condition that appears to be most prevalent on the 2007 model 340 engines with ETX CAT manifolds. The theory is that the extra heat generated by the catalysts allows the heat to build up in the bilge after the engine has been run for a period of time and then shut off. After it sits for a while a condition called "heat soak" raises the temperature in the bilge and allows the fuel in the line between the pump and tank to vaporize. The high pressure fuel pump will not pump vapor.

That being said, you can reduce the possibility of happening on any boat by doing a few simple things.

First, make sure your fuel filter is clean. As the fuel pump draws fuel from the tank through the filter, it creates a low pressure (vacuum) in the line. The harder the pump has to work the more vacuum is applied to the fuel. Fuel vaporzes at a lower temperature when it is exposed to a vacuum.

Make sure there are no restrictions in the fuel line between the tank and pump. The best condition is to have as straight and short of a line as possible. Each bend in the line can cause the pump to have to work harder and increase the vacuum.

After a hard run, try to let the engine run for a minute or two before shutting it off. This will help "normalize" the engine temperature and remove as much heat as possible from the engine. It might even help to disengage the shift control and raise the engine RPM in neutral to pump more water through the engine before shutting down.

Leave the bilge blower on after the engine is shut down to bring as much fresh air into the bilge as possible. Also, make sure the bilge vent hose isn't blocked, restricted or even disconnected from the vent and that the vent isn't blocked externally. It is not a bad idea on a hot day to lt the blower run all the time the engine is running .You'll also want to make sure to turn the blower on well before starting (if you shut it off) to make sure things are cooled off. This is not an unrealistic thing to do ... how many cars do you walk by on a hot day and hear the fan running after tha car has been shut off.

Your boat is significantly different than a car. The bilge of a boat typically does not have a lot of air circulating around it unless the blower is on. Also, cars have their fuel pumpslocated in the fuel tank.This keeps the pump cooler and allows the fuel between thepump and tank to be pressurized whichraises the vaporization temperature.

Try buying fuel from another source. We recommend using gasoline from a "Top Tier" supplier. Yuo can find which suppliers sell Top Tier fuel by checking out the following site. http://www.toptiergas.com/

I hope this gives you a little insight into vapor lock. It is a condition that has been around for a long time.It can be very frustrating but can be prevented in many cases by following a few simple procedures.

07-06-2007, 04:34 PM
Larry (aka engine nut),

Thank you for the clarification, I was hoping that you would reply :)

Although it has not happened to me (yet), I have read about many instances of vapor lock on this forum so I was concerned about it. Now that I have a better understanding of what it is, I will follow your suggestions to avoid it.

Thanks again.


07-11-2007, 09:07 PM
Engine nut.
I have the Indmar 325 in my 07' LSV. My dealership told me that there has been a small hadfull of Vapor Lock reports on the 325. My boat is in the shop right now getting a secondary pump put in.