Anybody on here an outboard motor mechanic

have a problem with an 07 mercury 50 2 stroke.as long as you dont go past 3/4 throttle its ok,but push it any further and within 15 sec it will shut off just like you turn the switch off,then when you try to start it back, starter will click for about 15 sec(but no start),like the motor is locked up.then after 15 sec or so it will start up and do the same thing all over...anybody help?

 

coil? Sounds electrical

 

impellor?

 

yeah,we think its electrical to,and it has 3 coils....

 

shut off at full throttle then takes forever to start up almost sounds like your flooding the engine with fuel to me... does it sputter start during those 15 seconds before it catching?

 

no.......it just shuts off like you turn the key off.then the starter just clicks for about 15 sec or so,like the solenoid is kicking in,but not turning the motor.then after a few sec it will start back up like a new motor.

 

http://www.marineengine.com/boat-forum/

 

yeah,its a friend of mines boat and he's already on that site,but nobody knows yet

 

Did you call the loca dealer and talk to the service guy? That usually is my first call.

 

he did that this morning.local mercury dealer says they have never seen one do that.its only has about 50 to 75 hours of run time to....

 

I'll ask around.. Our lakes are still frozen, but guys are getting the boats ready to go for the opener

 

thanks dude

 

I think it's either fuel starvation or blocked cooling water flow, here's my reasoning:

Known:
1) Engine operates normally under less than 3/4 throttle indefinitely
2) After a short burst of full throttle it shuts down and will not re-start for a short period

Chain of events:
1) Engine is operated at less than 3/4 throttle, fuel flow and/or cooling water flow is sufficient - engine operates as normal
2) Engine speed is increased to above full throttle, after a short time the fuel delivery system cannot keep up with demand causing a lean running condition (two strokes need fuel to get oil) causing excess heat and piston/ring seizure OR after a short time the cooling system is not keeping up with the heat the engine is making causing heat build-up and piston/ring seizure.

Things to check:
1) Is the fuel tank properly vented?
2) Is the fuel filter clogged / main jet in carburetor clogged / float valve in the carburetor malfunctioning
3) Is the thermostat operating properly (test in hot water bath)
4) Is there a blockage in the cooling system?
5) Is the waterpump impeller in the process of failing / failed?

 

thanks, i'll print this off and give it to him

 

sounds to me like, there is a wire or cable getting cut off to the full throttle. thats really weird. maybe there is a wire or something for the cut off switch? and also sounds like it might be getting too much gas, or not enough. does it just suddenly stop running or bog down then quit?

 

James.....start with the carburetor. sounds more like a fuel related incident that electrical...to me anyway. pull the carb(s) check the jets and all...check fuel pump to make sure its pushing fuel, and change the fuel filter if it hasnt been changed. sounds a bit like old gas may have set up in there some too.

 

yep, the new motors dont like the ethanol..Change the fuel filter, and pull the carb to check high speed jet

 

I did that to fix the starter solenoid on my old motorcycle, It started messing up again a year later, a 16mm wrench solved it that time...