Carb has "lime deposits"...

[trace]

Anyone on here seen this before?

http://www.wakeworld.com/MB/Discus/message...html?1243354628

By trace (trace) on Monday, May 25, 2009 - 9:26 am:

This carb came off of a houseboat that sat rarely used for about 5 yrs. This carb was rebuilt about 18 mos ago, and has been run regularly since. We treated the tanks with Seafoam and changed the filter/separators at least twice when we first started running it. Filters showed signs of water once. Boat started sputtering on quick throttle, which is why I pulled this carb. This had to come thru the filter and screen, and then congeal in the carb somehow. It looks and feels like heavy lime deposits.

What the heck is this nasitness, and how can I make sure it doesn't happen again? It's not feasible to pull the tanks to drain & clean out. Would have to pull the motors to pull the tanks.

[PIC]

By trace (trace) on Tuesday, May 26, 2009 - 6:36 am:

After cleaning it out, which has not been easy, it appears to have pitted the bottom of the bowl. I don't remember any pitting when we rebuilt the carbs last time. It was really difficult to clean up, had to soak a few hrs about 4 times, scraping the bottom in between, before it came relatively clean. I've rebuilt a lot of old carbs, and never seen this.

[99response]

Does the houseboat have fiberglass fuel tanks?

[trace]

No, they are aluminum. Thanks for the reply.

[99response]

Aluminum is good, did you region recently switch over to ethanol blended fuels?

We had all sorts of fuel problems around here when the switch happened, alot of the older fuel lines get eaten up by the ethanol.

But didn't see too many problems on carbed boats with decent (recently rebuilt) carbs.

[trace]

I have started seeing "May contain up to 10% ethanol" signs very recently, but the motors have only seen a couple hours of runtime since the beginning of this year.

[99response]

I'd put my money on the E10 fuel. I would go ahead and change out the fuel lines to newer ethanol resistant ones.

[scfdfireman]

I've seen the same condition on other aluminum carbs, and it's caused by water. I believe the water reacts with the aluminum and causes it to "bloom". If there's no moving parts or seals on the bottom of the bowl you can clean it out with a small Dremel tool wire brush... However, if your fuel tanks are aluminum too you should check the bottom of them also.