Does a gummed carb + 2-cycle motor = engine damage?

DocBob · Jul 7, 2009

A curiosity question came up the other day:

If a two cycle motor with more than one carburetor, had one carb gum up... would running the engine damage the cylinder(s) supplied by the gummed up carb???
No gas = no oil = cylinder damage?
Or is there more to it than that?

Chris1956 · Jul 7, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

yes, it is just that simple. A gummed up carb will make the cylinders it feeds run lean. Lean causes heat and low lubrication. These in turn cause cylinder scoring and possible bearing failure.

5150abf · Jul 7, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

Concur, it is the same as spraying starting fluid in a 2 stroke, no oil, no lube.

ondarvr · Jul 7, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

Rarely does an outboard wear out, gummed up carbs and stuck thermostats account for the vast majority of failures.

SeaNymph Man · Jul 7, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

ondarvr said:
Rarely does an outboard wear out, gummed up carbs and stuck thermostats account for the vast majority of failures.

OMG,this is starting to scare me something terrible. My 1970 Johnson 9.5
sat for a whole year without being ran with the previous owner before I
bought it,and the boat it is on,back in March of this year. It still had the old gas in the tank. I suspect the carb is most likely gummed up if gas stabilizer was not used. My motor seems to be getting slower and slower,even at full throttle. If she has ran lean all this time,could the gummed up carb be causing a lean gas/oil mix that could be scoring the cylinder walls in the process? If so,...it is only a matter of time before my engine dies then.

tx1961whaler · Jul 7, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

They are talking about multi-carb motors, not single carbs. A single carb motor will eventually just quit running if it gets gummed up and that doesn't cause damage.
If you ever suspect a problem with your motor, then identify the problem and fix it before it get serious.

ddrieck · Jul 7, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

correction....a single carbed two stroke may run lean if gummed up and lead to heat and scouring just the same as a muti carbed two stroke. I had an old Huskvana chainsaw that died an early death from this very thing.

SeaNymph Man · Jul 8, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

ddrieck said:
correction....a single carbed two stroke may run lean if gummed up and lead to heat and scouring just the same as a muti carbed two stroke. I had an old Huskvana chainsaw that died an early death from this very thing.

I agree. Should not make any difference whether it is single carb or multi-carb
motor. If a carb gums up,it will gum up no matter what. I wonder,would using
Evinrude/Johnson engine tuner,...or even Sea Foam in my motor,..save it from
a potential death from this very problem,...or is it too late for my motor?

ondarvr · Jul 8, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

On a multi carb engine you may not know one carb is not working correctly, so there may be little warning before it causes damage. On a single carb engine it may be more obvious that there's an issue, so you get a chance to fix it before it melts down.

To correct my first statement on stuck thermostats, I should have said cooling system problems.

jack1130 · Jul 8, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

How long running with a gummed-up carb before it's too late?

ondarvr · Jul 8, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

It just depends on how bad it is, you may get only two minutes, or it could be a full season.

jack1130 · Jul 8, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

How long running that way before irreversible damage is done to pistons, etc.?

05GlastronSX · Jul 8, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

There are simply way too many variables to tell. I suggest taking the carb off, disassembling it and thoroughly clean it. If you don't know how to do this, either get a manual that explains how or take it to a dealer and ask them to clean it for you. Don't wait too long however, or you can ruin the engine from something as simple as a clogged carb jet.

DocBob · Jul 8, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

Thanks for all the responses...I always know where to come for answers!

ddrieck · Jul 9, 2009

Re: Does a gummed carb + 2-cycle motor = engine damage?

I pull and clean my cabs at the beginning of each season even though a fuel stablizer is used when I put my boat away for winter.

I then rebuild the carbs evert 3 years, may be overkill but I have never had an issue with a lean running carb.

Back when I ran snowmachines I did the same as above.

Does a gummed carb + 2-cycle motor = engine damage?

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