1985 Mariner 25hp Outboard

[grady94]

I have a problem with a 25 hp Mariner outboard engine. The first thing was it was not charging the battery. I can easily pull start it but it doesn't charge the battery in the least. Now with a new battery it acts the same way. I can pull start it easily but the starter only barely engages when using the electric start. The starter was recently rebuilt. Could this be a problem with the voltage regulator or the rectifier?

 

[Barnacle_Bill]

Re: 1985 Mariner 25hp Outboard

Did you charge the battery before installing it? If you did check the battery cables at both ends to be sure they are clean and tight. Look for signs of corrosion around the base of the lugs and is you see any replace them. If you still have problems, use a heavy cable to momentary jump from the + teminal of the battery to the large red wire on the starter. If the starter acts like it should, replace the starter relay. If not, take the starter back to where you had it rebuilt. Next check your charging circuit by checking voltage at the battery with the motor off and again with it running about 2K RPM. You should see an increase in voltage. If you don't test your rectifier. BTW if you have ever hooked the battery up backwards or caused a spark anywhere, you most likely blew your rectifier.

 

[grady94]

Re: 1985 Mariner 25hp Outboard

Thanks I will try all you suggested. I have also been getting a shock trying to open the cowling when it is running and have since replace the spark plug wires. Still a little weary about trying that even with new wires. I noticed this one time when it was running a little rough at idle. Reached around to take the cowling off and zap! Ran fine though without cowl.