i got a 1991 65hp johnson. what should the correct voltage be at battery when engine is running. i got 17.4v when idleing. should the voltage be the same when throttled up as when ideling.
That's kind of high. It sounds like your motor might have a voltage regulator that is not working. Some have regulators, some do not.
What you need is a good factory service manual.
Check all your connections to be sure they are clean and tight. Also look for signs of corrosion at the base of the lugs. If you see any, replace the cable as it can be corroded inside the lug.
Get you a new rectifier before the battery is toast. They are fairly cheap for that model if you shop around. About $40.00 at the dealer...$29.00 at iboats site..
Are you measuring with a digital multimeter, or is that the voltage on an indash gauge...if it's the gauge, verify the reading with a DMM before replacing anything.
