if you think you have a gas problem?.

[lkbum]

I posted this in the mercruiser trouble shooting board, but since this applies to all boats, I though I'd repost here.

I have a Chaparral with twins. At the same point in time, Both engines developed exactly the same problem, pretty much classic vapor lock. I was convinced the gas was bad so I ran most of it out (took a while to burn 100 gallons) and put in fresh fuel. Did not help, actually seemed to get a little worse. One of the mercruiser trouble shooting guides said to check for fuel line restriction with a vacuum gage. Since both engines had independent lines to the tank, I discounted this as the cause. Well today, I pull the gas line check valve of one engines and holly crap, it had a piece of plastic (like the safety tab from a gas additive cap) lodged in the check valve. Pulled the other and it had the same thing. I was shocked. both engines, separate pieces of plastic lodged in the check valves. I checked, my pickup tubes did not have screens. Reassembled and boat runs fine now with no sign of vapor lock. See pics..

 

[jbcurt00]

Please dont start multiple topics about the same subject, Mercruiser topic deleted

Congrats on a easy and cheap fix.

 

[Tony T.]

Could it possibly be ? https://www.youtube.com/watch?v=3pMFobZXZww


Tony

 

[lkbum]

No, we've had nonethanol 89 octane on our lake for 2 or 3 years. I thought it might be winter grade fuel boiling a like easy (last fill up 100 gallons in Nov). That's why I ran most of the gas out and started with fresh fuel. It actually made the problem a little worse. I think this was because it added about 10 inches of head (drawing from my partially full tank).

 

[ondarvr]

That video is of the cheap junk fuel line that was used by a few companies, it should never have been rated as a marine fuel line, any fuel line really. Even Mercury used that stuff. That grey stuff created problems for a lot of boaters.

 

[Tony T.]

That video is of the cheap junk fuel line that was used by a few companies, it should never have been rated as a marine fuel line, any fuel line really. Even Mercury used that stuff. That grey stuff created problems for a lot of boaters.

And it's still creating problems for a lot of boaters. I say a very large percentage of people are still using it and what's sad is if the manufactures know that this ethanol fuel is destroying the inner lining there should be a class action law suit against them.

As far as being cheap yes material wise I agree but for what your getting as shown in the video $40 bucks is not cheap if your replacing quite often along with the boat mechanic fees.


Tony

 

[Chris1956]

To add to the OP. The check valves shown are antisiphon valves.

On another note, can anyone identify the pink plastic items? Additives usually have foil seals, sometimes foil over clear plastic. The fact that the two pink plastic items look to be the same shape, makes me wonder what the heck they are.

 

[lkbum]

I've seen them called either Antisiphon or Check. For me they turned out to be 1st stage filters! I've seen plastic like this in two places, peel off safety "tabs" on plastic caps of various items and peel off safety plugs on various tubing and fittings. I agree that the Stabil I've added over the years have had foil seals. The boat is a 2001 and I've owned it since 2003, maybe the previous owner (or who ever did the service) threw them in there (15 or so years ago). Or maybe they were from when the boat was original plumbed at the factory. What surprised me is how well they nestled themselves in the valve entrance.

 

[briangcc]

They look to be anti-tamper seals for plastic bottles. I know I've run across a few like that, for the life of me though I'm having difficulties today remembering what product I've purchased recently that had them. It's heck getting old!!

 

[Chris1956]

To be clear, those are antisiphon valves. The require a slight vacuum from the fuel pump to open, preventing fuel from siphoning into the bilge, if the fuel line breaks. Check valves are used in outboard fuel line primer bulbs and are simply a one way passive valve.

Different animal....

 

[lkbum]

Actually a ball check valve used for an anti siphon application? Same animal? see link (and nice hijack of the thread)?.. https://en.wikipedia.org/wiki/Check_valve