Rectifier ignition help...'99 115hp L4

[bwguardian]

I have a 1999 Mercury 115hp in line 4 cylinder 2 stroke. I just finished up a power head rebuild. Because of time lapse I pulled the battery and put a charge on it. Well, when I installed the battery back in the boat I attached the terminals crossed...positive cable to negative post and negative cable to positive post. The starter would only spin and not engage the flywheel to start the engine. I thought it was the starter and after several attempts I figured what I did stupidly. The engine of course was never cranked up obviously.

After realizing this I crossed the cables back correctly and the engine rolled over a couple times and busted off. I am now reading that the rectifier may be toast because of this. However, the tachometer is functioning so I am thinking the rectifier may be good but chances are the diodes are bad. I did notice while it was running on the hose that if I used the trim motor a little, the engine rpm's would come down some and I had to rev it a little to keep it going. This could be something not related but thinking it is. I am going to be testing tomorrow and any input is appreciated!

I do have a 1994 115hp parts motor and can't remember if the rectifier is the same or not...if so may just swap and see.

 

[roscoe]

97% likely it's toast.

Start it and put a meter on the battery, should read 14v +.

 

[bwguardian]

Checked it out this afternoon and battery was at 12.77 sitting. I started engine and it came up to 14.0 after idling for a bit. I then gave the rectifier a visual and noticed the 2 yellow wires had got hot at the quick disconnects. I went ahead and tried the other rectifier I had...it's the see through epoxy kind that I understand may be weaker. With that one installed, there was no change, so I left it be.

It still wants to bog a little at idle when I use the trim motor but I only have 30 minutes or so idle time on this fresh engine. I will check the timing tomorrow and put it under a load at the boat ramp on the trailer and see what happens. Motor sounds good and cranked right up...I am just thinking the rings need to seat.