- Oct 4, 2006
- 2,335
- Boat Info
- 2003 280DA and 1995 Sea Ray 175
- Engines
- Twin 4.3l and 3.0l, all w/ AlphaI GenII drives
I've about had it. This is now the 3rd time this year I've experienced the dreaded vapor lock issue with my 280DA with twin 4.3L MPI's. Experienced it once last year, our first full year with this boat.
This time, it was after dark about 20 nm from home with my family of four, and three family-guests on boat. Lightning in the distance. We had been trolling for fish for a few hours. Air temperature about 86F, high humidity. Water temperature about 80F. I had arrived to our fishing location using both engines, generator running, and then shut one engine down. Bilge blowers running the entire time. Fished for three hours or so. Then shut remaining engine down while we fished while drifting and ate dinner. Blowers still running along with generator.
After an hour or so, fired up both engines. The engine that we had been trolling with stayed running. The other that had been off died after about 15 seconds or running. Couldn't get it to restart. Classic vapor lock that I've experienced in the past. Shut down generator. Started home under single engine power with engine hatch now open. After about 30 minutes, trying every 5-10 minutes or so I finally got it started and kept it running. And just like that, it was fine. Thankfully we never got caught in a thunderstorm!
I've tried every recommendation that Mercruiser has mentioned in the vapor lock tech bulletin 99-07 concerning the issue. Fresh fuel, blowers always running, even leaving the hatch up when we leave the boat for a brief period. Thought I had it under control until this. The only other recommendation is to install fuel "booster" pumps in the line nearer to the tank to more of the fuel line under pressure so it can't vaporize. But this is an expensive option. Nonetheless, I'm about to trailer the boat for the rest of the season and use our remaining fuel account allotment for these boost pumps (~$400.00 each). But will it really work?
Has anyone fought this issue...and solved it? Has anyone had to add the boost pump(s) and had it actually solve the problem permanently? How about any other novel solutions to the problem? Obviously while talking around the coffee mess at work, non-boaters offer various solutions. Just brainstorming here:
This is super frustrating to say the least. And I don't want to be worrying if the boat will start, every time I shut it off (like I do now).
Tom
Mercruiser 99-07 Tech Bulletin
This time, it was after dark about 20 nm from home with my family of four, and three family-guests on boat. Lightning in the distance. We had been trolling for fish for a few hours. Air temperature about 86F, high humidity. Water temperature about 80F. I had arrived to our fishing location using both engines, generator running, and then shut one engine down. Bilge blowers running the entire time. Fished for three hours or so. Then shut remaining engine down while we fished while drifting and ate dinner. Blowers still running along with generator.
After an hour or so, fired up both engines. The engine that we had been trolling with stayed running. The other that had been off died after about 15 seconds or running. Couldn't get it to restart. Classic vapor lock that I've experienced in the past. Shut down generator. Started home under single engine power with engine hatch now open. After about 30 minutes, trying every 5-10 minutes or so I finally got it started and kept it running. And just like that, it was fine. Thankfully we never got caught in a thunderstorm!
I've tried every recommendation that Mercruiser has mentioned in the vapor lock tech bulletin 99-07 concerning the issue. Fresh fuel, blowers always running, even leaving the hatch up when we leave the boat for a brief period. Thought I had it under control until this. The only other recommendation is to install fuel "booster" pumps in the line nearer to the tank to more of the fuel line under pressure so it can't vaporize. But this is an expensive option. Nonetheless, I'm about to trailer the boat for the rest of the season and use our remaining fuel account allotment for these boost pumps (~$400.00 each). But will it really work?
Has anyone fought this issue...and solved it? Has anyone had to add the boost pump(s) and had it actually solve the problem permanently? How about any other novel solutions to the problem? Obviously while talking around the coffee mess at work, non-boaters offer various solutions. Just brainstorming here:
- Add electric water pump that I can circulate seawater to keep things cool, even with engine off? Possible?
- Add primer bulb like on an outboard boat to squeeze out the vaporized fuel? Possible?
- Higher replacement CFM blowers (Mine are 200cfm now which seem to be the highest I have been able to find)?
- Adding blowers or other methods to cool the engine room and bring in more fresh ambient air?
This is super frustrating to say the least. And I don't want to be worrying if the boat will start, every time I shut it off (like I do now).
Tom
Mercruiser 99-07 Tech Bulletin
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