Mercury 2.2 hp outboard - Dies after 5 mins

[k25824]

Hello all,

does anyone know the possible cause for my Mercury 2.2 hp 2 stroke outboard (1987) to only have about half its power left at full throttle and to die after about 5 minutes of running? Any help would be appreciated.

[TOM]

Originally Posted by k25824

Hello all,

does anyone know the possible cause for my Mercury 2.2 hp 2 stroke outboard (1987) to only have about half its power left at full throttle and to die after about 5 minutes of running? Any help would be appreciated.

we have one of these and had the same problem .You have gunk in your carbie .You will need to take the carbi out and open it up .spray all the jets with carbie cleaner .Do all this over a bucket so you don't lose any of the bits.

www.byamee.com

[sartorst]

is the gas cap vent open? been there dunit

[Acushla]

This is almost bound to be a fuel related problem. Firstly eliminate the easy issues to check. (1) there is plenty of fresh fuel in the tank (i.e. and no water). (2) is the vent working properly (you can release the main filler cap as engine faulters to check this). (3) take off the cab bowl without spilling the content and look for contamination (water and particulate matter). (4) check the effect of the idle screw to confirm the engine respone to its adjustment. (5) finally strip the carb down and blow through all the jets (avoid poking wires into the jets if you can).

These are very simple machines and the fault is generally overcome with following through these steps.

Acushla

[k25824]

yes, small cap ontop of gas cap is open so air is coming through. I think the carb is due for a cleaning. thanks.

[bobconnie]

If ya been useing Elthanol/gasoline you have a bigger problem! 2 strokes don't like this stuff you will need to clean the carb well maybe even need to boil and rebild ! and don't ever use the alky gas again !! we have stations down here that advertize for non alky gasoline, cus we have so many 2 strokes down here!!m just sayin don't use the stuff !!

[Cormorant]

Removing the carb is pretty easy . . . and spraying it with carb cleaner takes just a minute (plus maybe a few more for soakage). . . . Then after you reassemble it all and it starts right up and runs strong, you feel like a mechanical genius.

[ranger58sb]

Originally Posted by bobconnie

If ya been useing Elthanol/gasoline you have a bigger problem! 2 strokes don't like this stuff you will need to clean the carb well maybe even need to boil and rebild ! and don't ever use the alky gas again !! we have stations down here that advertize for non alky gasoline, cus we have so many 2 strokes down here!!m just sayin don't use the stuff !!

Guess that's sort of a geography-specific solution, though. No non-ethanol available around here...

k25824: If the rest of that doesn't work, and if you're using E10 ethanol, a couple other things to check. Ethanol will eventually separate (aka phase separation) the alchohol from the gas from any water in there, so you might also sometimes see low RPMs (your symptom) when burning water/gas, or even extreme unexpected RPMs -- if the engine will burn any of the alchohol layer at all. Also, the E10 formulation will attract more water, so if you leave the vent open overnight (for example), you may find your ethanol degrades more quickly. Recommendations include using a fuel stabiliser every time (see Practical Sailor for brand tests and choices) and also use the fuel more quickly, don't store it over 6 months (per magazines, but I find 30 days sometimes problematic).

In more extreme cases, you can check whether the ethanol has "cleaned" the inside of your fuel lines, or even the tank (I'm guessing that's probably an internal tank your model has?). If it has scoured or degraded the inside of the lines or the tank/fittings, etc., you may need to do a bit extra work to clean the carb (e.g., with compressed air through a needle valve) and/or replace some of those fuel lines.

-Chris

[rajens]

I have a 3.3 Merc OB that will die if the gas cap vent is not open. During running, vibration causes the vent handle to rotate closed and over time to not letting air in so that fuel no longer flows with gravity thus starving the engine.

Since the 2.2 is almost identical in design, this may be your problem.

Hope this is helpful.

[GordMay]

Greetings and welcome aboard the CF, rajens.

[boatbod]

Is the engine pumping water? If it runs smoothly when first started but dies later, I'd suspect either an overheat or a failed fuel pump.