That sounds like voltage regulator/rectifier. My techs are not in until monday but I will check with them. Or if you would like to give us a call our number is 856-825-0111. Ask for Joe or Dave

 

I think you have a couple of things going on.
1. You want to test voltage at battery and gauge before and after the motor is started up. With the motor running you should not get more then 14.5 volts. If your getting more then that the regulator is bad. If not your gauge is bad
2. If you regulator is bad you can kill the Tach. Mine did not jump all over but it did read about 1000 rpms to low. If the regulator is fine I would pull the plug on tach look for corrosion also check your grounds.
3. It could be alot of things carbs or ignition related

 

I test the battery at the battery with battery testor because my volt guage always reads low probably has a weak ground and my tach always jumps goes high then low but then "settles in" but since I do not push the boat no faster than I have to once I get on plane I just try to stay at that speed. Maybe I should check my grounds but there is no hurry now not till April anway:wave:

 

Seaker and fdformicloa, sounds like you both have voltage regulator issues. Give Dean at King Marine Outboard in Sewell NJ a call. (856) 582 - 5222. They are on route 47, delsea drive just up from Glassboro.

 

I want to thank everyone that has gotten back with answers so far. For those others like DUNK and/or Joe from BARNACLE BILL'S if your able yet to reply, could you? Also a few others who's thoughts would be appreciated. THANK YOU. BUCK HUNTER, I will give Dean a call soon.

 

There's really not much more to say. You need to check your voltage at the battery at about 1800rpms. With a fully charged battery you should be seeing about 14.2-14.7 volts on a digital meter. I'm not saying it's not your tach, but if the VR is bad the tach won't work right. Being that the tach is doing something and voltage is off there's probably 90% chance it's the VR.

 

Tachometer

I had a tachometer go bad with my 90hp Merc. My Tach would jump all over the place and at some point be accurate. I took the tach to a merc dealer and he tested it at the store. I replaced the Tech and everything was fine.

 

Thanks Tbarto, that's sounds to easy so you can bet I'll try it first.:thumbsup: for the tach. problem.

 

I have an OMC tach sitting in my barn if you want to give it a try. Should be a real simple test....

 

Sorry been sick for some time and now getting back around. We see volt gauges go bad all the time and cause what your seeing. Wiht the key off is the guage reading 12 volts. If so then its the volt guage. As for your tach it can be a few different things.

You may not want to wait till april to have it looked at as that is when many service shops get weeks behind.

 

JOE:Glad to hear your up and about. Although I didn't put it on the Barn I'm sure like alot of others my prayers and well wishes were going out to you. Hope it's all behind you now and take good care of yourself. I want to get the bottom on my 19ft wellcraft panted again by you guys again and also get it up and running right. Is it too early to bring it in to have this work done or should it wate awhile?