Is my 75 hp Yamaha charging the battery ??

[ggray]

I don't see any increase in battery voltage (using multi meter) with engine running. 12.4 v is all it shows.

My guess is it is not charging, that it should read 13 v or more.

Am I wrong ?

 

[99yam40]

Re: Is my 75 hp Yamaha charging the battery ??

13.5 to 14.7 would be correct at upper RPMs

 

[ggray]

Re: Is my 75 hp Yamaha charging the battery ??

Thanks; I thought so.

Is there any simple testing to determine the problem ?

 

[99yam40]

Re: Is my 75 hp Yamaha charging the battery ??

According to my c40 manual you measure the peak voltage coming out of the lighting coil with a peak reading voltmeter or DVA adapter and regular meter with the regulator disconnected. Should read 9V cranking and 25 V @1500RPMs . Above spec replace regulator below spec replace lighting coil

It would do you well to get a manual for your motor. It will give you all the specs for your motor and what and how to do all your repairs and maintainance