Engine not restarting after running a while

[grywlfbg]

I haven't noticed this in my boat but it could be vapor lock. Fuel will vaporize around 213F and can create air bubbles in the lines that can mess w/ the flow of fuel. Your idea of running the blower and/or idling for a bit to bring the engine temps down will both help.

If you really want to isolate it, next time it does it, find the fuel rail and pour cold water on it. If it fires up after that then it's definitely vapor lock.

 

[suke]

So I've had the boat out now a couple times since changing the plugs. The motor that had the issue no longer does, at all. The problem hopped to the other motor. UGH! So I pulled those plugs and gapped them down to the lowest end of acceptable range to be within stock spec. Problem is now gone on both motors. Went out yesterday and did all the same things I normally do and never had a hot start issue. Was on the water today for 10 hours doing just about everything and never once a hot start issue: beached for a while and floated, cruised all over the lake and back several times picking up and dropping off people, filled the ballasts and surfed, towed the tube, and floated while listening to music.

 

[JetboatBrad]

So I've had the boat out now a couple times since changing the plugs. The motor that had the issue no longer does, at all. The problem hopped to the other motor. UGH! So I pulled those plugs and gapped them down to the lowest end of acceptable range to be within stock spec. Problem is now gone on both motors. Went out yesterday and did all the same things I normally do and never had a hot start issue. Was on the water today for 10 hours doing just about everything and never once a hot start issue: beached for a while and floated, cruised all over the lake and back several times picking up and dropping off people, filled the ballasts and surfed, towed the tube, and floated while listening to music.

Nice. I haven’t had the problem come back since I first posted that. Its happened a handful of times before that with no one specific engine. It’s just been so random. I hope you’re right and I’ll regap too. What did you narrow the gap down to?

 

[suke]

Nice. I haven’t had the problem come back since I first posted that. Its happened a handful of times before that with no one specific engine. It’s just been so random. I hope you’re right and I’ll regap too. What did you narrow the gap down to?

.030 on both engines or really close to. I had one box of plugs that were at .031 right out of the box, so I left those alone and put them in the motor I had the problem with initially. Second box of 4 plugs were at .034 or .035. Those gave me the fit on the other motor. So gapped them really close to .030....no more issues. My issues showed up the first outing after changing the plugs, so I'm fairly confident I've got it licked.

 

[jacoviii]

@swatski Has found running the blower during cool down and before restart / or all the time helped. He had this issue during rider change over while wake surfing. The issues is the 1.8 NA motor does heat soak. The ECM adjusts the fuel map due to the heat. This makes it a hard start. As you try to start 4-5 times it moves a little water though the motor and it brings down the heat.

 

[suke]

@swatski Has found running the blower during cool down and before restart / or all the time helped. He had this issue during rider change over while wake surfing. The issues is the 1.8 NA motor does heat soak. The ECM adjusts the fuel map due to the heat. This makes it a hard start. As you try to start 4-5 times it moves a little water though the motor and it brings down the heat.

That wasn't the case for me. I idle A LOT, especially getting to my anchor spots. So, if the blower or idle or even slightly higher idle would have worked for me then I never would have had the issue. Those were the first things I tried and didn't work for me. Glad the spark plugs were a simple fix for me.