5.7 Edlebrock Carb and gas issue (1996)

[Monsterbash716]

Quick back story...

Purchased a 310 Silverton pending see trial...which was a disaster.

New long blocks installed in 2016 and 2017 with under 10 hours on them...obviously very little use. The are 5.7 carbureted (1409 Edelbrocks 600 CFMs) and thunderbolts.

Leaving the marine on the sea trail the Starboard side motor stalled and would barely start. When it did start it would die when adding any throttle. The Port side motor wouldn't rev over 2000 RPM.

Compression test on both motors (another thread) was good. Plugs and cap look good (plug were new). I also confirmed with the marina that did the work the long blocks were crate and new.

It sound like it was running out of fuel. So I took the Starboard side carb apart and rebuilt it.

The carb didn't look 'that' bad and was obviously rebuilt recently (was told this also when the motor were replaced). I was blowing out the carb with canned air (the best I had at the time) and hit the tube that feeds the secondary and what you see in the pics is what I got. The stuff that landed on my hand was only a small part of what came out. It had to be completely packed

Soaked and rebuilt the carb and it runs REALLY nice...but my question.

What the heck is that stuff?!? What my course of action going forward?

Thanks!

 

[makomark]

my guess would be some crud that has built up in the fuel system....

I would inspect the filter(s) to make sure they are free of 'it' as well...if not, I'd be inclined to get the tank flushed by a company that has the 'heavy equipment' to do it correctly...

 

[o2batsea]

Yeh, I'd have the seller do the fuel system polishing before taking possession. I'd also recommend a marine survey before any other surprises ruin your day.

 

[sandkicker]

About once every three seasons I have to take my 2bbl MERCARBS (TKS) apart and clean the rock hard, sand colored crud out of the venturi jets with a #70 drill. I use a good fuel conditioner in my ethanol laced fuel and replace the fuel filter/separator annually. Still...crud accumulates. I've come to the conclusion that it is formed by a chemical reaction between the ethanol laced fuel, the conditioner and atmospheric moisture.

 

[Dieter]

Yeh, I'd have the seller do the fuel system polishing before taking possession. I'd also recommend a marine survey before any other surprises ruin your day.

X2 on this this may be through out the fuel system. Not that it may be a deal breaker just will have a cost to perfom that you'd perfer comes out of the sellers pocket.

 

[guyjg]

It's granulated varnish from fuel that was not treated. The boat is 25 yrs. old and as stated earlier it is in the entire fuel system, especially the tank. Installing a 10 micron fuel/water separating filter will help.