Rubber bits clogging my carburetor - Honda 50HP 1999

[MattFL]

This is part warning to others with older motors, and part curiosity to know if anyone else has had this problem. I had a sliver of rubber clog the float valve on one of my carburetors, preventing that cylinder from getting any gas. As best I can tell, the sliver (pictures below) appears to be a piece of gas line, though it may have also come from the fuel pump. It's about 9mm long, appears to be slightly curved, and is extremely brittle. I'm now replacing everything rubber downstream of the fuel filter, including the pump, to prevent it from happening again.

This could have been a life threatening situation. My teenage son was driving as we were traversing a very busy inlet on a Saturday afternoon, headed into the ocean. Suddenly my 1999 50HP Honda, which for the last 20 years has been rock solid, was down on power and shaking, no longer able to get the boat on plane. It was obvious one cylinder was out. Fortunately the seas were mild, so I was able to trouble shoot enough on the water to determine that the bottom carburetor was bone dry, no gas at all, and we made the return trip slowly on 2 cylinders. The cause turned out to be the ~9mm and very brittle sliver of rubber (pictures below) clogging the float valve on the bottom carburetor from the supply line side. As best I can tell it appears to be a piece of fuel line, and I'll dissect the fuel lines to verify as time allows, but everything rubber plus the pump is being replaced to be safe. Is this another ethanol related casualty?

If you have an older motor and don't want to risk being stranded, it might not be a bad idea to replace all rubber hoses and the fuel pump if you haven't already!

 

[dingbat]

As best I can tell it appears to be a piece of fuel line, and I'll dissect the fuel lines to verify as time allows, but everything rubber plus the pump is being replaced to be safe. Is this another ethanol related casualty?

The useful life of a fuel hose is defined by the EPA is 10 years. Many marine hose manufactures recommend replacement at 6 years. Your double the life expectancy of the hose.

A fuel hose should be soft and pliable. if not, it needs replaced.

Don't forget about the fuel fill hose. I've had to replace two in my travels.

Leaking fuel into the bilge from a compromised fill hose usually doesn't end well.

 

[MattFL]

It would appear that you are correct on the fuel line. It's still relatively soft on the outside with no visible cracks as it has been sprayed with silicone after every use, but apparently the inside is much different. Fortunately my tank is above deck, though I did have a buddy put about 10 gallons in his rod holder once. That was one hell of a mess...

 

[GA_Boater]

Even some of the supposedly ethanol safe replacement hoses suffer. The gray ones have been mentioned in the forum numerous time. I had one with a "safe" liner fail when the liner stated flaking.

 

[ahicks]

It sure looks like a piece of fuel line. Does this 50 have the filter that is located just upstream from the fuel pump on the port side of the engine? If it does, that sliver had to have made it through that filter to have come from one of the fuel lines from there to the tank. If it doesn't have that filter, shame on you!

If you're replacing the lines, don't forget to do the one that runs down across the bottom front of the engine, from the filter to the quick connector. Not the easiest hose to replace, but it does get harder than a rock because they are often overlooked when it comes time to do the lines.

 

[MattFL]

The filter is there, it came from one of the fuel lines that is down stream of the filter, or the fuel pump. There are several fuel lines past the filter; one into the fuel pump, 2 out of the fuel pump and one of those branches into 2 more to feed the top 2 carburetors. The problem was with the bottom carburetor, so it has to be the hose from the filter to the pump, or from the pump to the carburetor. Or from the pump itself.

 

[ahicks]

My point was there's not a lot of real estate that might have shed that part. First thing I would do is have a look inside that pump. Note the screws holding it together are tamper proof screws you'll need a special bit to deal with. I think I got mine at Harbor freight. Also, I think that pump is serviced as an assembly. Not sure you can get parts for it.

 

[MattFL]

I did not see parts for the pump when I ordered, so I just ordered the whole pump. $80, ouch! But the parts arrived yesterday, so the plan is to replace everything this morning and test it out this afternoon, and hope that it works because we have a tournament this weekend! I'll do a full autopsy on the old parts after this weekends tournament and post the results if I find anything interesting.