Mercury power problem Any advise please

[eula30]

Hi, I have a mercury 50hp 1985 4 cylinder 2 stroke nice motor. Motor start and runs good for about 10 minutes after that it lose power on full Throttle. It will still idle really good start very quick and runs but when I go full Throttle the motor doesn’t run like when it was cold. Any advise please

 

[Mufasa]

Re: Mercury power problem Any advise please

When you say it still idles good I have to suspect the stator assy. It provides the operating currant for the ignition system and has two separate windings. One is low speed and the other is high speed. It crosses over at about 2,000 rpm's. It is refered to as high/low stator red & blue wires. It can be tested at cranking speeds with a peak volt meter. Red voltage plus blue voltage should be at least 250 volts. There are other componants that could act flunky (switch box ect...) but you need to start at the beginning.

 

[eula30]

Re: Mercury power problem Any advise please

Thank you, i will do that tomorrow and let you know.<br />Thanks

 

[eula30]

Re: Mercury power problem Any advise please

Hi, I just came from the lake and got my situation down to two. The problem is in spark plug number 2. (No spark) (Coil, sparkplug and sparkplug cable are good they wore tested) Now there is a cable coming down from the stator to the power pack and from the power pack to the number 2 coils that’s where the problem is. I need to try the cable that comes down from the stator to the power pack to see if is any power on that cable (don’t know how to do that) if there is power on that cable then the power pack may be bad and if is no power on that cable then maybe the problem is on the stator or in the cable it self. Any advice on how to test these cables please? I really want to try the cable for power before taking the motor a part. I really appreciated all your help.<br />Thank you.

 

[FatBack]

Re: Mercury power problem Any advise please

Do a compression test. Your rings could be worn or worse.

 

[eula30]

Re: Mercury power problem Any advise please

They read 120 on all of them. <br />Thanks

 

[rickdb1boat]

Re: Mercury power problem Any advise please

Do you have more than 1 pack?

 

[eula30]

Re: Mercury power problem Any advise please

hi, I only have one pack<br />Thanks

 

[eula30]

Re: Mercury power problem Any advise please

Hi, any advice on whats the voltage on the wires that is coming out of stator to the powerpack/switch box? <br />Thank you