Mariner 100hp - Whole Host of Problems!

[Redrox007]

Hi Guys,<br /><br />Great site -- I've been reviewing some of the posts to find out about the problems I'm having but I'm still a bit confused as to whats happening with my 1988 Mariner 100 OB so here goes:<br /><br />1) Battery seems to be overcharging -- I think this might be a rectifier problem(?). So far this summer we have gone through 3 batteries, I tried to recharge one of the batteries this weekend and it had no water in it. Sometimes after running just fine I'll start the motor the next morning and get nothing -- even if I had disconnected the accessories leads the night before. I've checked to see if one of my accessories is staying live and draining the battery but I can't find anything....<br />How do I determine if it is a rectifier problem?<br /><br />2) The starter also seems to be misfunctioning. Sometimes even on a new fully charged battery I try to turn the engine over and it just clicks. I've lightly tapped the starter motor and sprayed wd40 on the spinwheel and it works ok after that -- I'm guessing I need to replace my starter? Any ideas on cost? Could the starter be overcharging my battery or have anything to do with the other electrical problems I'm having?<br /><br />3) Reverse - this problem started this weekend -- I try to put the motor in reverse and I get a 'clicking' sound and it doesn't go into gear. I think it might be reverse backlash but it doesn't seem to be a cable problem -- any ideas?<br /><br />Any advice you guys could give me would be great.

 

[Chris1956]

Re: Mariner 100hp - Whole Host of Problems!

Redrox, Lets start with the rectifier. First disconnect the three wires. Second using a ohm meter or even a continuity tester, check the dioads in the rectifier. There are four of them contained in the rectifier and they should pass electricity in one direction only. So the test is across adjacent terminals. Check from the plus terminal to an AC terminal. You should have continuity one way, and when you reverse the leads on the ohmmeter, uou should have no continuity. If you have continuity both ways or none either way, the rectifier is shot. Repeat test from the plus terminal to the other AC terminal. Now repeat test from the AC terminal to the metal case of the rectifier, and once more repeat the test from the other AC terminal to the case. I think you will find one dioad is shorted, thereby shorting your battery to ground, or through the stator.<br /><br />Now the starter. Have a fully charged battery. Use a jumper cable to bypass the solenoid. That is, jump from the "hot" side of the solenoid to the starter voltage connection. If the starter works properly, the starter is good. Now using a clip lead or piece of wire, connect from the hot side of the solenoid to the start terminal (not the black wire) of the solenoid. If the starter cranks, the circuit from the ignition switch is bad. If nothing happens, it is likely the solenoid is bad, or has a bad ground connection.

 

[Redrox007]

Re: Mariner 100hp - Whole Host of Problems!

Thanks Chris,<br /><br />Is it difficult to replace the rectifier yourself?

 

[Chris1956]

Re: Mariner 100hp - Whole Host of Problems!

Redrox, You can buy a better than OEM at Radio Shack for about $4. It requires some modifications to your wiring harness, however. The OEM part is probably $50, but requires no modifications to the harness. Simply remove the old part and install the new part (one bolt) and put the stator wires on the two opposite terminals, the battery charging wire on the center(and up) terminal.<br /><br />If you want to go with the cheap part, buy a 25Amp full wave (or Bridge) rectifier at radio shack. It has four spade terminals and a mounting hole in the center. Take a 1" piece of wire and put a female spade terminal on one end and a ring terminal on the other. Attach the spade terminal to the rectifier's minus terminal, and the ring terminal to a bolt through the rectifier into the cowling support, where the old one was. This grounds the minus terminal to the block, like the original. Now put female spade terminals on the two stator wires and the battery charging wire and connect them to the rectifier, the stator wires go on the AC terminals, the battery charging wire goes on the Plus terminal.