Vapor lock or something else?

[Stinnett21]

I probably dealt with this for 1/3 of a season. It would only occur on the hottest of days. Come fall when it cooled down the problem went away. Once I suspected it was due to vapor lock I would loosen the fuel filter and let it breath a bit, retighten and it would restart.

 

[jimmbo]

Back in the Days of Carburetors, and Fuel Pumps on the Engines the pulled Fuel from the Tanks, Vapour Lock was common on hot Days(Gets a lot Hotter under the Hood of a Car, compared to the Bilge/Engine Compartment of a boat) I would carry a bottle of Water that I would Pour on the Fuel Pump, and the Line feeding it. Rarely did the Line from the Pump to the Carb need cooling as it was under Pressure, but if Hot enough the Fuel in it would Flash, and the rising Pressure would force the Inlet Valve in the Carb open, flooding the Carb. That is not Vapour Lock, that is called Percolation, Cooling that line would reduce that.

 

[vetplus40]

Okay. I think that the "closed loop" part confused me. I will look for the valve on my boat as soon as I can. Thanks.

 

[Stinnett21]

Mercruiser check valve assembly. Looks like Amazon has some options. Pretty easy job on mine. Access wasn't bad.

 

[vetplus40]

Mercruiser check valve assembly. Looks like Amazon has some options. Pretty easy job on mine. Access wasn't bad.

I checked mine and it was working just fine. I added about 6 gallons of premium fuel (which topped off the tank) and took it back out for a test run.
It was over 90 degrees and very humid. I ran the boat on 3 different excursions. Waited different time intervals before restarting ( 15, 30, 45, 60 mins, etc.) and the boat started each and every time.
I wanted to siphon the old gas out, but could not get a siphon bulb to work. As such, I just added in new fuel.

 

[Stinnett21]

Happy inexpensive endings are good to hear!

 

[vetplus40]

Happy inexpensive endings are good to hear!

Well, after the $500 towing bill anyway.
I did find a disconnected vacuum type hose that may or may not have been part of the issue. I talked to a local mechanic that wasnt sure what the hose was for.

 

[1985 Century Mustang]

Well, after the $500 towing bill anyway.
I did find a disconnected vacuum type hose that may or may not have been part of the issue. I talked to a local mechanic that wasnt sure what the hose was for.

You should definitely look into Boat US. It's $175 for the year and you get free tows. I'm not sure how many tows they limit you for the year, but it's well worth it, especially in your case. For what it's worth I have had the same issue with restarting my boat while it's hot, I have a 1985 Merc 3.0 A1-G1 140hp, I'm assuming it's vapor lock also, I have yet to figure it out.

 

[1985 Century Mustang]

As with with my possible Heat Soak issue, im now considering purchasing this phenolic carb spacer. I've read good things about them.