Sediment Bowl Washer & Ethanol

[Clucas]

Perhaps got a bit lazy during my winterization process last fall and didn't drain sediment bowl or carb. First cranks of the season wouldn't catch, so first drained the carb -- still no luck. Envisioning a gummed up carb, I first went to drain the sediment bowl from my mechanical fuel pump and was very surprised to find the sediment bowl gasket had turned to complete mush - like over-saturated open-cell foam and just disintegrated between my fingers. The sediment bowl was filled with lots of rubber bits as well which would be caught by the polishing filter.

Ended up pulling the carb, cleaning with Gunk-Out and compressed air and replacing the sediment bowl gasket (glad I had a spare). Bolted everything back in and she started immediately Hugely satisfying, btw.

Sediment bowl gasket was one season old and was replaced last year when I did a rebuild of the fuel pump because the same thing had happened to the pump diaphragm -- pretty much disintegrated, leaving lots of rubber bits in the pump chamber (yes, I also changed the polishing filter element). Anyone else experienced this with the sediment bowl gasket or pump diaphragm?

[Dave Neptune]

Hmmm?

Clucas, I have the mechanical pump and have not touched it in many years running the E-fuels with no problems. I would look to the additives or combination of them for a possible cause. The gaskets on my bowl are fine, so maybe you got ahold of some really old ones.
Are you using an additive or even a couple of them?

Dave Neptune

[BunnyPlanet169]

Also - as recently pointed out on another thread - confirm A1 fuel lines UL rated for ethanol containing fuel. Older lines will shed rubbery crumbles...

[67c&ccorv]

Where did you get the gasket from?

[Clucas]

Where did you get the gasket from?

The gasket was purchased here from our host. The only additive I've ever used has been MMO (I did use Sta-bil one year several years ago after draining the entire tank in place to get rid of some old fuel -- nothing else added beyond some Sta-bil). Following is a link to some pictures showing what I found last year on rebuilding my fuel pump. A little difficult to see, but the diaphragm had what resembled a blister and was no longer moving fuel at the rate it needed. Lots of rubber bits -- rebuilt the pump and she's good as new.

http://chrislucas.smugmug.com/Other/GreyGoose-Projects/n-RcgQrn

Chris

[hanleyclifford]

Nice pictures - really illustrates the issue well.

[Clucas]

Nice pictures - really illustrates the issue well.

Didn't get pictures of the sediment bowl and gasket remains -- 'melted' gasket and gasoline all over my hands... thought I would dissolve my phone, but the fuel pump pictures are similar to what what was in the sediment bowl. Gasket looked like a partially decomposed worm.

[Administrator]

Just curious... What sort of filter(s) do you have upstream?

Bill

[Clucas]

Just curious... What sort of filter(s) do you have upstream?

Bill

Hi, Bill.

I have a Racor upstream and an inline polishing filter downstream going into the carburetor. Both were changed last year. I have a priming bulb upstream from the Racor. After the rebuild of my fuel pump last year (see photos at http://chrislucas.smugmug.com/Other/...jects/n-RcgQrn), I had visions of a nearly clogged polishing filter -- in hindsight it would have been interesting to cut it open to see what it had caught.

My gut suggests this is an ethanol issue perhaps exacerbated by an older rubber sediment bowl gasket and an older fuel pump diaphragm, but am open to other suggestions (perhaps it's Bush's fault...). Fuel is straight 87 octane regular from the pump -- the only additive is a bit of MMO added to the tank.

The sediment bowl gasket issue occurred over the winter -- I had fuel in the sediment bowl and carb over the winter (sloppy on my part). When she just cranked and wouldn't catch (which wasn't surprising given fuel sitting in the carb the entire winter), my first step was to empty the sediment bowl and drain the main passage in the carb, then re-prime and try again -- no luck. Next was to remove the carb and clean all the jets using carb cleaner and some compressed air. It's a really quick job and she fired up immediately. (Looks as though I'll be modifying my winterization procedure). She runs and sounds great now but the disintegrated gasket has me stumped.

Thanks for your insight.

Chris