50hp Yammi charging problem

Bluefin480

Recruit
Joined
Aug 8, 2010
Messages
2
I recently bought a centre console with a 2003 50hp Yammi 2 stroke. Since buying it i have had problems with flat batteries. I checked today and it is not charging and this is where I get confused.

I checked the wiring looking for a charging wire from the motor to the battery and there isn't one. The only wires going to the battery are the main positive starter motor wire and the negative. All the other wires go through a plug inside the cowl and go straight to the control box.

Does anyone know if there should be another wire from the motor to the battery or if there should be a wire coming back from the control box to the battery. Any hints, wire colours to look for etc would be greatly appreciated.

Cheers
Mark
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 50hp Yammi charging problem

there is no dedicated charging wire to the battery.
it goes from the rectifier assy to the battery lug on the start relay or a bullet conector beside the start relay.
3 green leads from the stater provide a/c current to the rectifier.
 

Bluefin480

Recruit
Joined
Aug 8, 2010
Messages
2
Re: 50hp Yammi charging problem

Thanks for the tips. It made fault finding much easier. There are only two wires on my model coming from the stator on my model (must be only one coil not two).

I checked the voltage from the stator and it ranged between 12 and 35 volts depending on revs so I am assuming the rectifier/reg is the problem.

One more question. One of the wires from the stator is spliced to another wire that goes to a solenoid on the middle carby. I presume this has something to do with richness of fuel as when it was unplugged the motor started to run very rich and struggled to idle.

Can someone explain to me to theory of this relay and the use of the AC power to run it. (i presume it has something to do with volts V's revs)

Cheers
Mark
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: 50hp Yammi charging problem

It is the Prime Start Enrichment system. do a search for more info.

The 12v power runs the heater when the motor is running, closing off an orifice restricting the extra fuel when motor has warmed up.
 
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