5.7L inboard won't start when hot

["Chris' Craft"]

The boat is a 1991 Malibu Skier 195 Euro F3 with a 5.7l 350 Chevy Mercruiser with a quadrajet carb.

The first two times the boat has been out on the water this season it starts fine and runs fine but when you shut it off after being warmed up it won't start until you wait 30 mins with the engine cover up.

Then the third time we took it out, we weren't getting water because the impeller went bad. Before we knew it had a bad impeller and were trying to diagnose why it was running hot, we shut it down and tried to start it and it fired right up, even though it was extremely hot.

The last time we took it out we ran it without shutting it down....knowing what would happen if we did. After about 30 minutes of running it and skiing it started to cut out like it was out of fuel. Then less than a minute later it stalled and wouldn't start again.

We pulled it out of the water then 20 mins later when we got it home we tried starting it on the trailer and it started right up.

All of these times the I haven't smelled any fuel when trying to start it and giving it lots of throttle.

The water temp has been 87 degrees Fahrenheit here lately.

 

[boat1010]

Re: 5.7L inboard won't start when hot

Sounds to me like it is vapor locking. Are you running ethanol in it? Mine will do the same thing. If you are running ethanol try to burn out all that gas and put some in without ethanol and see if it still does it.

 

[Bondo]

Re: 5.7L inboard won't start when hot

The boat is a 1991 Malibu Skier 195 Euro F3 with a 5.7l 350 Chevy Mercruiser with a quadrajet carb.

The first two times the boat has been out on the water this season it starts fine and runs fine but when you shut it off after being warmed up it won't start until you wait 30 mins with the engine cover up.

Then the third time we took it out, we weren't getting water because the impeller went bad. Before we knew it had a bad impeller and were trying to diagnose why it was running hot, we shut it down and tried to start it and it fired right up, even though it was extremely hot.

The last time we took it out we ran it without shutting it down....knowing what would happen if we did. After about 30 minutes of running it and skiing it started to cut out like it was out of fuel. Then less than a minute later it stalled and wouldn't start again.

We pulled it out of the water then 20 mins later when we got it home we tried starting it on the trailer and it started right up.

All of these times the I haven't smelled any fuel when trying to start it and giving it lots of throttle.

The water temp has been 87 degrees Fahrenheit here lately.

Ayuh,.... Welcome Aboard,.... When it won't start,.... Pull some spark plugs,...
Are they Firin',..??
Is there Gas,..??

1, or the Other, is Missin'....or it's Floodin'....

 

[ChrisDinCA]

Re: 5.7L inboard won't start when hot

i've been experiencing the same problems with my 91 f3... lots of research has led me to the fuel. most gas these day's has 10% ethanol added to it.. this is causing a lot of problems with carborated engines, like what you're experiencing.

See this web site for a lot of very useful info on the E10 fuel and how to deal with it, www.fuel-testers.com
my carb is currently on the bench, i'm replacing the float to a bronze type and lowering the float level a bit. i'll know how things are pretty soon.

also, hopefully you changed your impeller out and now carry a spare. it's about a 20min change out, but can ruin your day if you don't have a spare on board
good luck.

 

[ChrisDinCA]

Re: 5.7L inboard won't start when hot

one other thing, CHANGE THE FUEL/WATER separator/filter. Ethanol absorbs water, so having a fresh filter is critical.
c.