Removed and cleaned Boat carbs

[swampratt]

I was wishing the soaking I gave that pontoon boat engine would clean stuff from the carbs.

Soaking involved starting it on fresh 2 stroke mix and letting it run ..It would not idle unless I kept choking it.

But I got gas through it and in the bowls.
A few weeks of soaking and then firing it back up did NOTHING.

I found hard black crud in the bottom of the fuel bowls and the main jets .072" were completely clogged with hard black crud.
Emulsion tubes clogged with hard and some gooey black crud.

Air passages clogged in some places.
2.5 hours of hand cleaning and poking holes clean with wire and torch tip cleaners and spraying mineral spirits through everything and they are now clean.

Waiting on a gasket set for them so i can finish up the job.
I bet it runs very well when I get these back on as they cleaned up really nice.

 

[dlbleak]

Does the hard black crud have an almost ‘sweet’ smell? If so, that could ethanol.

 

[swampratt]

Could be the fuel but it is not sweet it is old gas stinky. The engine and boat have not ran since 2004 and the fuel tank has black tar in the bottom that smells like old gas.
No I did not use that fuel tank. Getting rid of it.

This engine is an oil injected 90 HP Mercury. Not that it matters.

 

[Mr.Glock]

90hp is a good size! Looking forward to some completion photos and a ride!

 

[Waltercat]

Varnish equal lacquer. The only thing to dissolve lacquer effectively is lacquer thinner.
Add some to gas when you know you will run it all out and will help. Done this to mowers that have sat for years. How much to add isn't critical as long as it's ran out and not left in fuel system for long periods.
YMMV.

 

[2busy]

I'm trying to get a carb flowing on a 1952 Farmall super A. Guess I will be taking it off again tomorrow and getting the torch tip cleaners out.

 

[HKP7M13]

That bucket of super smelly black stuff they call carburetor cleaner will do a good job if you can still buy it. I want to clean some fuel injectors with a ultrasonic cleaner. What is the best cleaning solution?

 

[Ready_fire_aim]

Are you going to bypass the oil injection and premix the gas?

 

[Mr.Glock]

Are you going to bypass the oil injection and premix the gas?

Good question. On those older one I never trusted the oil injection. Mixed myself.

 

[swampratt]

That bucket of super smelly black stuff they call carburetor cleaner will do a good job if you can still buy it. I want to clean some fuel injectors with a ultrasonic cleaner. What is the best cleaning solution?

There are many liquids that work here is a link to guys that power their injectors during cleaning.
https://www.ls1lt1.com/threads/fuel-injector-cleaning.89818/


I have a 70 Mercury oil injected engine that is a 1998 and no issues with the oil injection part of it.

Now if you ever run it out of oil you are screwed.
There is a gear on the crank that is made of steel and spins a "plastic" gear that drives the oil pump.
If you run out of oil the lube is not in the engine and it gets hot and melts the plastic gear and no more oil injection.

I rebuilt a V6 inboard jet drive 2 stroke mercury engine that was ran out of oil.
Scored a cylinder buck luck for the girls that owned the boat just 1 cylinder.

That was not a fun job.
It did not take them a month to return with the same issue because they did not fill the oil container and ran multiple tanks of straight gasoline through it.

I did not fix it again.

In the Mercury shop manual it stated to mix 50:1 oil in the fuel and have the oil injection tank full and run the rebuilt engine on that for 10 hours.
Buddy did just that no issues.

I guess Mercury does not trust the oil injection either.

Extra oil in a 2 stroke makes them run lean.

I have NEVER ran a 2 stroke out of fuel. IN the mercury manual from 1969 it states DO NOT pull the fuel line and run the engine out of fuel.

This will starve the engine of oil and you will have an engine that sits dry and can rust.

The proper way is to remove the bowl screws and let the fuel drain from the carbs.
On my 1975 mercury 50 hp 2 stroke I have always ran 100% gas and Quicksilver oil and never ran it out of fuel and I do not pull the fuel bowl plugs either and those carbs are spotless and run excellent every time I take it out.

Go figure.