poor charging on 1974 115hp merc

[pdee]

My 1974 115hp IL6 motor idles about 800 rpms. When using running lights and radio my volt meter drops below 12volts. I have to increase rpms to 1200-1300 to keep above 12volts. I noticed this after Ideling one night for a couple hours and found my battery weak the next day. When runnong fast I see about 13 volts.<br /><br />1 - Is this normal or should I be getting a good charge at low rpm?<br />2 - If this sounds bad where should I start to look for a problem?<br /><br />Thanks<br />PDee

 

[WillyBWright]

Re: poor charging on 1974 115hp merc

Those alternators are barely stronger than a trickle charger. Still, it's possible for your rectifier to be partially failed and it'll only pass about half of the charging current. But before you do anything else, make certain your battery connections are clean and TIGHT!

 

[Clams Canino]

Re: poor charging on 1974 115hp merc

It may well be normal..... is the battery itself getting soft?<br /><br />-W

 

[pdee]

Re: poor charging on 1974 115hp merc

The Battery was new in the spring. I just installed the motor and all the battery connections are new and clean.

 

[andy6374]

Re: poor charging on 1974 115hp merc

If you are using wing nuts, toss em they are crap, and get some stainless steel nuts and star washers.

 

[timmathis]

Re: poor charging on 1974 115hp merc

Like clams said that may be normal. My inline does not charge as well at a idle. Tim<br /><br />P.S. How is lake wylie?

 

[pdee]

Re: poor charging on 1974 115hp merc

Originally posted by Tim Mathis:<br /> Like clams said that may be normal. My inline does not charge as well at a idle. Tim<br /><br />P.S. How is lake wylie?

Thanks for the info.<br /><br />Lake wylie has been very low for months. Duke lowered the lake when Katrina was comming but we got no rain from the storm. We went about 90 days without rain. However it has not stoped raining for about the last week. <br /><br />The lake is up nicely now but the water is very muddy from the rain.

 

[timmathis]

Re: poor charging on 1974 115hp merc

Well, Maybe it will clear up and fill soon. That is no good muddy and low. I think all the lakes around here are a little low due to no rain. Good luck, Tim