1996 Johnson 112 SPL

[crabby13]

Took the boat out week on the Friday the 4th crabbing. Ran all day. She stalled a couple time and started right back up. Later in the day I noticed a slight decrease in turn strength but she never failed to fire.

Charged for about 4 hours Saturday night on a 2 amp charge. Noticed that the "fully charged" light wasn't light when I had to disconnect.

Headed for the launch. Turned her over and got it to start then stalled, Tried to turn it again and much slower. Tried again and wouldn't turn over. I get about 25 - 30 seconds of turn then it acts as if the batteries are dead. I've been chasing this electrical issue for a couple months now and can't seen to figure the issue.

These are 2 brand new batteries and I just replaced the rectifier. With the motor running I was getting about 12.93 volts at the battery terminals.

Don't know how to check the the alternator or if this is an cabling issue.
​
Any ideas or thoughts would be welcome.

​Thanks

 

[Barnacle_Bill]

Recheck and slowly increase RPMs. When it gets to about 2000 the voltage should be reading closer to 14 VDC.

 

[emdsapmgr]

If you have a tach for the engine, does it function normally? Your engine should came from the factory with a combination rectifier/regulator, so not sure just what rectifier you replaced. Check your starter by jumping it direct with automotive jumper cables direct to a strong battery. If it cranks normally, it's ok. Then look at the solenoid and the key switch next. A bad/old solenoid may not pass current with age, causing cranking issues.

 

[crabby13]

Should I change out the key switch? Not sure how to check the solenoid.
I'll try the direct with the battery. Is there a way to incorrectly jump the unit? I don't want to damage any (more) of the electronics. The tach has always been hit or miss. Some days it works. . .others not.

 

[racerone]

The starter motor is easily damaged by excessive cranking.------Take the starter apart for inspection.---Sounds difficult but easy to do.

 

[crabby13]

Should I change out the key switch? Not sure how to check the solenoid.
I'll try the direct with the battery. Is there a way to incorrectly jump the unit? I don't want to damage any (more) of the electronics. The tach has always been hit or miss. Some days it works. . .others not.

 

[crabby13]

Racerone - I could remove the starter and shroud. . .wouldn't know what I was looking for from that point.

I'm going to check that I have 12 VDC off the solenoid to the starter and 12 volts to the starter.

It just doesn't make sense to me that I only get around 25 to 35 seconds worth of crank time before the batteries (brand new) won't turn over the engine.

 

[racerone]

Well, you must establish whether the starter is at fault or something else.---------2 bolts take the starter apart for inspection.----All it takes is a visual inspection and an ohmeter. to do a simple check.------Most folks have one of those meters or your friends will have one.-----------Nothing will jump at you and after you are done you might say " that was easy ?---------On reassembly of the starter you might need to make a " special tool " from a paint scraper or piece of sheet metal.