charging circuit issue with 1989 johnson 90.hp vro

[adamthorpe]

hello everyone Iam working along side my dad were doing some repairs to our 90hp Johnson up north. I posted a thread last week about having a overheating problem witch turned out to be the power pack. We went up north this weekend and replaced it and it running great no more haveing to get towed back to shore every 20 mins gotta love that.
We decided to test the charging circuit. We have a good battery and with the motor running we get 12.6vdc on old meter and with the motor turned off still 12.6vdc seems like a faulty charging circuit. what should we test next?....... magneto/stator ,rectifier is this what caused the power pack to give out every 20 mins and now that we have a new one on there its just nice and strong and not giving out so quickly
thanks for reading
Adam Thorpe

 

[emdsapmgr]

Re: charging circuit issue with 1989 johnson 90.hp vro

That engine has a combination voltage regulator/rectifier on it. Normal battery voltage would be 12.6. When running for 10-20 minutes, a volt gauge should creep up to 13.5 volts, indicating the battery is being recharged. Possible you have a bad rectfier/regulator. Does your tach read correctly? Once started, the engine makes it's own ignition power. The only time the battery is used is for starting and for the power trim. (also the radio, lights, etc.) You can run for some time with a bad rectifier/regulator before the battery starts to run down.