ran out of gas which then caused vapor lock

[gregski]

So I know there are lots of posts about vapor lock issue but this is a slight twist on the usual story. We have never experienced the typical vapor lock issue. Yesterday we were out all day enjoying perfect conditions, right up to the limit of the gas tank! (We knew we were getting low, but I've never burned that much in the day... it was worth it). We sat for about 45 minutes before getting 5 gallons into the tank and it started right up but then wouldn't accelerate and eventually started running really poorly: chunka, chunka, cough, die. One person had an experience that by running the pump to the point of dry it caused the pump to fail; so we started to worry about that. Then the idea of vapor lock hit me. I poured a bit of cool water on the line to the pump and voila, everything was perfect again. (Thanks to the forum for putting that idea in my head)

I don't think that sitting for the 45 minutes caused the vapor lock. I've never had it happen to us in much warmer weather and it wasn't particularly hot - upper 70's and we were in the shade when this happened. But I think that once the line was "unprimed" from the loss of fuel, it didn't take nearly as much heat to get it vapor locked and the pump couldn't overcome this until I cooled the line. So if you have the maximum amount of fun and run out of gas, be mindful of the vapor lock issue.

[kaneboats]

Well, there is no question that a variety of conditions can lead to the same result. The key is knowing what to try to get it resolved and be on your way so you are not stuck and waiting for a tow. Kudos to you for knowing symptoms and acting for the benefit of your crew.

[kelauben]

I'm experiencing a problem when the boat sat all winter and when I picked it up from storage it had no gas in the tank. Now I can't get it started. Doesn't get an fuel to the carbs. I don't know if I've got an issue with bait lock or something else. Any suggestions anyone? '98 Outback.

Thanks

Karl


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[zabooda]

Disconnect the gas line at the carb and jump the fuel pump. The pump should operate and fuel flow from the line. If the pump runs and no fuel flow, you will need to find the obstruction.

[kelauben]

I ended up checking the electrical at the pump and found nothing when key was in run position but had voltage in start position. I also used a siphoning pump to try to pull fuel through the fuel pump and was successful at that proving there was no obstruction. Then I applied external power to the fuel pump only to find it was dead. Ordering new fuel pump now.

That makes a new fuel pump, new starter solenoid, new secondary solenoid and new 50amp breaker to get things going this year. At least when I sprayed starter fluid directly into the carb the fired right up and purred like a kitten. Hopefully, the fuel pump will be last item.

I must say, getting a copy of the Clymer manual for the Indmar engine that's in my '98 Outback has been a lifesaver. Complete with troubleshooting guides and electrical diagrams. It's been great.

Karl


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[zabooda]

You really need to jumper the fuel pump directly from the battery as there is an oil pressure interlock switch that seems to give some people issues.

[kelauben]

I used an external battery to test in the same manner. I found out that the oil pressure switch only connects once it reaches 4psi per the Indmar service manual. Once I isolated the fuel pump, I discovered it would work at all. New one is on order.

Thanks

Karl


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