check valves on 2 stroke merc

pine island fred

Lieutenant Junior Grade
Joined
Dec 20, 2002
Messages
1,144
Sunk the boat in a heavy storm. Anchor line broke overnight and find the boat washed up on shore with the surf packing it with sand, shells and salt water. After 2 days I manage to get to the motor harness, hook a battery up and fill it with STABL fogger thru the plug holes and down carb throats. Later manage to drain the fuel pump, lines and carb float bowls of water.Portable tank lines were ripped away from motor as the tank was half full and floated away in the surf.
Rinsed the sand/ shells off the motor and out of air box. Got gas real heavy with oil 10 to 1 and the damn thing started up! Not good but it ran. Then tackeled the carbs for a rebuild. All carbs had a noticable amout of a substance kind of like tooth paste along with a bit more salt water. Determined the oil injection was working so I ran it on a 50 to 1 pre mix just to get more oil thru it. Motor is running well now on strait gas except for idle.
Idle is all over the map. Has a mind of its own. Sometimes right on, sometimes stalls and others it starts racing all in the course of 5 mins. on muffs or in the water. I have the MERC factory book and it points out CHECK VALVES ( 4) under the reed valve plate installed in the block. Does not say what they do or how they would affect performance. Does anyone know? If they were clogged with that tooth paste substance would it give me erratic idle speeds? Motor was shut down tilted full up as I abandoned ship with the beer and tobacco ( priorities) . Guess I should mention it is a 2002, 50 hp. 2-stroke, 3 cyl. Appreciate any thoughts you might have. thanks fred.
 

thinksun

Seaman Apprentice
Joined
Apr 15, 2007
Messages
49
Re: check valves on 2 stroke merc

Check valves can and do get clogged or sticky. The result is a bad running engine as they help bleed off excess fuel in crank.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,103
Re: check valves on 2 stroke merc

Fred, Normally you would need to disassemble the motor down to its bearings and clean the block, carb, starter etc to remove all traces of salt water and silt. The electrics tend to go bad after a while, as well.
 
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