1986 40hp Yamaha, should it charge the battery?

I have an engine which seems to be the combination of a 1989 6H4 L 558276 - 40etlf (lower unit, bracket with electric tilt, and cowling) and a 1986 powerhead. I spent some time on the phone with Yamaha support and this is what we came up with the serial numbers on the block and bracket and the model numbers.

Anyway, should this electric start motor charge the battery? I have the 1986 shop manual and can't seem to figure it out. When running it currently does not charge the battery.

My other question is does this motor require a converison box to run a tach and what is the model number of the unit, it is not listed in the shop manual either. It just shows the green, black and blue wires connecting directly to the tach.

Chris

Re: 1986 40hp Yamaha, should it charge the battery?

Yes it should charge the battery, but will not handle large loads or deep cycle batteries. It also does require the conversion box for the tach.

Re: 1986 40hp Yamaha, should it charge the battery?

Ray:

Thanks, what I found out was the rectifier was "shorted out" as both inputs were connected to the same green wires coming from the lighting coil. I reconnected the rectifier properly and now the battery seems to be charging. I have an 85 amp hour deep cycle battery and while idling the battery voltage slowly comes up. i.e. at rest the battery reads 12.7v and while the engine is running it reads 12.8v and slowly going up. I am used to seeing around 13.4v when an engine is running and charging, as you said in your earlier post, is this battery too large which is lowering the output voltage of the rectifier?

As to the tach conversion box, can you point me to a link to the device? Is it made by Yamaha? By looking at the wiring diagram, it seems that this green wire that goes to the rectifier is the same wire used by the tach?

Chris

Re: 1986 40hp Yamaha, should it charge the battery?

Good news, went fishing tonight and watched the voltage on the battery go up to 14.1v, we are charging! Now if I can get the tach sorted out I will be all set.

Chris

Re: 1986 40hp Yamaha, should it charge the battery?

The tach converter assy is a Yamaha part. When using a deep cycle battery, the amperage to charge if low is too great for the system. By being sure the battery is fully charged before using, you should not have a problem.