No Thermostat? What...

[joe_db]

I am building a new hot section. I have seen both Galvanized used and black pile. Was leaning toward black pipe, but getting the sections are/will be a chore.

Is Black Pipe the way to go?

Also, did not have an anti-siphon, so also have a Marlon on its was as well.

Thanks
Pete

Galvanized pipe gives off nasty fumes for a time that can actually make you sick. Use the black pipe.
* it is actually called zinc fever https://en.wikipedia.org/wiki/Metal_fume_fever

[Oaktown27]

Finished building the hot exhaust riser. Thanks to the local Grainger as it seems black pipe is not a stocked item any more at the local plumbing shop.

Pulled the carburetor, and plan to clean the jets as suggested. I wasn't planning on rebuilding the carb with new jets and only going to clean it up. Hate to spend 100 bucks on the kit if I don't need to. Any thoughts on this?

Still need to drain the fuel pump sediment bowl and check the screen.

Also, I don't have a scavenge tube installed. Looks like the hole in the manifold is plugged. I assume I should reinstall one?

Feels like I am almost there, and do say the A4 is looking (and starting) much better than it was.

Thanks

[Dave Neptune]

Yes the scavenge tube is important as a safety factor and adding air for idle purposes. It is just plain ole 1/8 copper tubing with a 1/8"NPT adaptor for installation.

Dave Neptune

[sastanley]

Oaktown Pete, welcome! Great job methodically attacking one issue at a time. We'll help you get her running great again!!
Sometimes we preach around here that when you tackle too many issues at one time, you can't always figure out what was actually causing the problem in the first place, but you're doing it the right way IMO.

[Oaktown27]

Happy Ending

Happy to report that after pulling the carb and cleaning the jets, cleaning the pump bowl and adding the scavenge tube, power has been restored!

Thanks to all for the support and suggestions. Have to say, was a bit intimated when I started on this, but know have built up familiarity and confidence with the A4.

Only thing left is to adjust the reverse, which seems fairly straight forward.

Couldn't have done it with out the Afourians....

[Peter]

Great news you have it running nicely again.

Food for thought - why was the carburetor gunked* up?

Perhaps there are issues upstream that, until resolved, will continue to gunk things up?

Peter

PS - I think the technical term is actually "KRUD" per Dave Neptune

[sastanley]

PS - I think the technical term is actually "KRUD" per Dave Neptune

Ha ha ha ha ha ha..

[Oaktown27]

Yup, Krud it was. Probably going to slip a fuel filter in the line. The mechanical fuel pump cup was gross, and I probably should buy a replacement. Since it is a copper line from the pump to carb, was thinking of putting it in front of the pump. Something to put on the list.

Bright work has now come to the top of the list as well as reverse adjustment.

Thanks again guys.

[ndutton]

There's no downside to filtration but under the circumstances you describe you'll catch the krud before it reaches the carb while doing nothing to address the source of the krud. Make the filter easy to change and carry spares because I suspect you'll be replacing it often.

[joe_db]

There's no downside to filtration but under the circumstances you describe you'll catch the krud before it reaches the carb while doing nothing to address the source of the krud. Make the filter easy to change and carry spares because I suspect you'll be replacing it often.

BTDT - I ended up taking the fuel tank home and found it full of rubber bits from a failing fill hose besides for random stuff from many years of use.
It got a thorough cleaning before going back on the boat and the fuel fill hose was replaced too.

[sastanley]

Oaktown...also, several of us have removed the hard copper line and gone to soft..that allows you to put polishing filters almost anywhere you want. I have one in between the mech pump and the carb, along with a fuel pressure gauge so I can be sure the pump is supplying fuel. Sorry, I don't have a good pic of that available.

[GregH]

Hope this linking works.. pic of the hose, gauge and filter

https://www.moyermarineforum.com/forums/showpost.php?p=128041&postcount=85

[sastanley]

Thatch mod!

FWC'd Thatch'd motor with no bypass! (and you can just see the sideways chrome fuel pressure gauge near the carb, so it is sorta on topic!)

This picture is amazingly 7 or 8 years old. I have since bumped up to the next size HX, and re-installed the t-stat. When this pic was taken (no t-stat under the housing), that little HX could barely keep up and I was running 180-190°F all the time. If anything went wrong I had no margin.

I found a larger similar style SenDure HX at the salvage place in Stevensville, MD a few years ago. It is the same height, larger diameter, and probably double the cooling capacity, The reinstalled t-stat happily cycles all day long @155-165°F.

[mhinnc]

T-Stat Gasket

I'm about to install a new thermostat and gasket. There wasn't a gasket in place when the old one was removed (liquid gasket material was used.) Is the gasket installed above or beneath the thermostat? Thanks.

[ndutton]

Beneath. There's a recess in the upper thermostat housing for the thermostat flange to locate it properly.