81 140 Johnson drain on battery

[The twoms]

My 1981 Johnson 140 will start and run fine when the battery is fully charged. However, after a day or two of fishing or skiing the battery is not powerfull enough to start the engine. The firt time it happened there was enough juice to spin the starter but not enough to spin it fast enough to engage. I then bought a new battery and it worked fine for a while but it started doing the same thing. Is something draining the battery? and if so how do I find it?

 

[DJ]

Re: 81 140 Johnson drain on battery

mjk,<br /><br />Your engine should charge the battery, albeit at only about six amps.<br /><br />With the engine running, you should see 14 volts across the battery terminals with a hand held voltmeter. If not, you are not charging. <br /><br />If you are not, the most likely cause is a bad rectifier.