Ethonol and carburetors

[brynifer]

Over the last few seasons, my S150TXRW has developed power loss in the cruising range. Sounded like a cylinder or two was dropping out intermittently.
This season it got worse. I finally got around to rebuilding the carbs after alot of troubleshooting. Every single float (total of 6) were sitting way too hi, meaning there was not nearly enough fuel in the bowls. The needle valves have a rubber end which contacts the float. They had become swollen, I am assuming from ethonol in the gas. After correcting the hight of the floats the problem is gone.
Just thought I'd pass this along.

[amahaork]

Drain gas off season

[brynifer]

Yes, that would help. I find it interesting that with all the chat about ethanol eating into fuel lines and water in tanks, I have seen nothing about this particular problem. My local marine shop wouldn't even entertain conversation about it when I went to him for rebuild kits. When he did offer he just said "we can get them but we don't use them, the gaskets last forever and we clean them with ultrasonic." Having taken one apart already and in doing so, destroying the bowl gasket, I politely ended the conversation. He clearly didn't even want the sale of a rebuild kit from me. I would lastly like to say to anyone who might be just browsing the forum, if your motor develops these symptoms, keep in mind what I found and check the carbs sooner rather then later.

[scofflaw]

Seems like your resolve was to correct the float height. Was ethanol to blame for that ?

[TownsendsFJR1300]

When I re-powered in 2007 I had them replace the fuel line from the transom filter to the engine. They used marine grade (I think Mercury was imprinted on it).

Back then I used ethonol.

Shortly thereafter, while doing maintenance under the cowl, I found a bunch of crap in the Yamaha fuel filter.

After some investigating, it was found that NEW piece of 3/8 fuel line, a layer of the innerds CAME APART / OUT (parts like a long curly cue). The Yamaha filter caught it.

The transom fuel filter was fine, just that one line that got replaced again...

I stopped using ethonol and only add Yamaha's Ring Free and K100 as a stabilizer. The non-ethonol with the K-100 has stayed fresh for me for over TWO YEARS...(large built in tank, maybe using 5 gallons a day on an outing-so I don't replace fuel often)..

IMO, just pay the extra for the non-ethonol, the headaches are not worth the savings..

[scofflaw]

I buy the cheapest pump gas regular I can find and drive it like I stole it.

Just say no to snake oil additives as well. I park this boat for 8 months at a time. Fog it and drain the gas. Works for me and cheap too.

[pstephens46]

Yes, that would help. I find it interesting that with all the chat about ethanol eating into fuel lines and water in tanks, I have seen nothing about this particular problem. My local marine shop wouldn't even entertain conversation about it when I went to him for rebuild kits. When he did offer he just said "we can get them but we don't use them, the gaskets last forever and we clean them with ultrasonic." Having taken one apart already and in doing so, destroying the bowl gasket, I politely ended the conversation. He clearly didn't even want the sale of a rebuild kit from me. I would lastly like to say to anyone who might be just browsing the forum, if your motor develops these symptoms, keep in mind what I found and check the carbs sooner rather then later.

Sounds like the mechanic was not interested in selling you parts for DIY. They are around here too. Probably get away with ethanol if you run everyday. Ask Rodbolt what he thinks about it. I have seen too many issues with it...

[TownsendsFJR1300]

Heck, older cars run regularly with it sometimes have fueling issues from it and their GENERALLY run way more than an outboard engine..

Bad stuff...

[cpostis]

Over the last few seasons, my S150TXRW has developed power loss in the cruising range. Sounded like a cylinder or two was dropping out intermittently.
This season it got worse. I finally got around to rebuilding the carbs after alot of troubleshooting. Every single float (total of 6) were sitting way too hi, meaning there was not nearly enough fuel in the bowls. The needle valves have a rubber end which contacts the float. They had become swollen, I am assuming from ethonol in the gas. After correcting the hight of the floats the problem is gone.
Just thought I'd pass this along.

I think your needle valves have one cone shaped rubber end, the other end being plastic with a slot (at least the new ones are like this).
So, do you mean "rubber end which contacts the seat" or "plastic end which contacts the float"? What's the make up of your new needle valves?



Did you actually have to adjust the float height by bending the tabs? Or did just replacing the needle valves take care of the height level?

Just curious?

Thanks!!!

[pstephens46]

Rubber or silicone I wonder? Silicone seems almost indestructible.

[cpostis]

Rubber or silicone I wonder? Silicone seems almost indestructible.

Original 1963 patent said "rubber", now???

[brynifer]

not positive that ethanol was the cause but the end which contacts the float (not the valve seat end) was discolored and swollen. Changing the needle valves brought the floats near perfect. I did bend the tabs slightly. Every other part of the fuel system is very clean. There are no other signs of ethanol damage. Fuel lines are in perfect condition and the last filter mounted near the engine never had evidence that rubber was breaking down. Note sure of the ethanol percentage at my station. Never thought to check.

[99yam40]

If they sell anything above E10 there can be mistakes made when unloading trucks

[pstephens46]

EPA wants E15. Vote for Trump.....

[brynifer]

Yes, the lesser of two evils i guess