Mercury 50hp Starting problems.

[Roger2]

Hi Guys: Need help. 1989 50 hp Mercury 3 cylinder with oil injection Outboard. Worked for 3weeks to finally identify the Mercury Kill switch a doing most of the problem. Can anyone tell me just what this switch does. I think it activates the choke. Anyway I am still having a problem starting the engine with this switch removed, but it is still having problems. I think the engine is being flooded with gas when I choke the engine with the switch. Finally get the engine started with a blue cloud of smoke coming out the exhaust. Here is what I have done in the past two weeks. Removed the spark wires, Switch box and 3 coils and took them to a Mercury Mechanic. He check them out and said they were all OK. Engine is still fouling out on the #1 cylinder. Problem seems to be with the choke or with the carburators or even with the reed valves and yet that doesn't make any sense. <br />Please tell me where to go from here<br />Roger2

 

[sprinter144]

Re: Mercury 50hp Starting problems.

I'll help you with one of your questions. The mercury kill switch grounds the capacitors in the switchbox (draining the power to the spark plug coils) to stop the engine in case you hit something and the prop comes up out of the water.

 

[snapperbait]

Re: Mercury 50hp Starting problems.

Sounds like a sticking float in one carb holding the needle off the seat allowing too much fuel to flow and flooding the engine... Rebuild carbs...

 

[Roger2]

Re: Mercury 50hp Starting problems.

Hi guys:<br />Sprinter144-----<br />Thanks for the reply. When I took continuity check to the black/yellow wire that was hooked into the kill switch, I had full continuity to ground. Maybe this switch is OK and something else is shorted. Because I am still having problems starting engine. Should I be able to check this kill switch with this blk/yel wire connected? Or do the wires have to be removed. If so, I think I do have a problem and maybe the carburators are the problem. But why did the motor start right up when I took this switch out of the system. <br />Snapperbait-------<br />How do I check the carburators to prove that this is the problem.

 

[hondon]

Re: Mercury 50hp Starting problems.

If you had continuity to ground on this switch it is bad. That is a kill switch and you kill this ignition by grounding it .

 

[hondon]

Re: Mercury 50hp Starting problems.

You can't bench test a switchbox.Do you have spark?Are the carbs flooding over?Primer solenoid stuck open.Cloud of smoke when she finally fires off? Then i'dd guess you've got spark but you've also got some fuel issues somewhere.

 

[Roger2]

Re: Mercury 50hp Starting problems.

Hi guys:<br />Still having trouble. Engine starts with blue cloud of smoke but does not fire on #1 cylinder. I will rebuild the carburetors this fall but need to identify short problem now. I want to go fishing. Yesterday when I removed the cover and started the engine, engine started on 3 cylinders. and ran fine. Something is shorting out cylinder #1. I taped up the kill switch wire thinking that it shorts out the switch box and maybe the switchbox is hanging up on the #3 cylinder wire that leads to the coil. How do I test out the switch box?<br />Any help will be appreciated.<br />Roger2