1967 Mercury 50 hp buzz noise

[1973Chieftain]

I tried starting my'67 Mercury 50 hp this afternoon for the first time this year. Fresh gas, charged battery, and a hose etc. It cranked for about 20 seconds normally, but when I hit the choke button it stopped cranking. All that happens now is a buzz sound coming either from the lower end of the starter or where the main cable plug plugs into the engine. The starter gear is not engaged to the flywheel and the flywheel turns over by hand normally. I've never had an issue before with this engine nor heard such a buzzing noise... any ideas what it could be? Thanks!!!

 

[Bosunsmate]

Re: 1967 Mercury 50 hp buzz noise

Have you tried jumpiing straight to the starter?
they often buzz when they go awry or arent getting enough juice

 

[GA_Boater]

Re: 1967 Mercury 50 hp buzz noise

Hey Chief - We have to keep these oldies puttin'. I just got mine running today after some magneto problems.


Couple of things, battery connections - clean and re-tighten. They may have gunked up over the winter. Cheat the solenoid - Jump from the battery lead on the solenoid to the solenoid start lead. On my 500 those are the two (one small/one large) closest to the starter. I use a screwdriver. If the cheat works, it's most likely the starter. Hope this helps.

 

[Aqualift]

Re: 1967 Mercury 50 hp buzz noise

Ditto. I had a similar issue with my 65 Merc 500. It was a simple clean and retightening of the wires.

By the way, I just rebuilt a 1968 Merc 500 from spare parts. So now I have two sweet Merc 500's! A 68 and a 65.

 

[Texasmark]

Re: 1967 Mercury 50 hp buzz noise

Did you forget to charge your battery? Pulling out the choke may have had nothing to do with your battery pooping out. You just drained what juice was in it.

Mark

 

[1973Chieftain]

Re: 1967 Mercury 50 hp buzz noise

I jumped from the battery direct to the starter which turned it over nicely. It then started just fine the regular way with the key. I ran it and shut it off several times before the problem resurfaced. After jumping it again it started via the key again... seems to reset itself somehow after the jumping and starts working again. The battery is new and charged up, but the starter sounds fine when it works after the jump. Sounds odd for a bad starter or is that normal?

 

[GA_Boater]

Re: 1967 Mercury 50 hp buzz noise

My solenoid is getting flaky and need changed. When it acts up it sounds like yours except I don't get a buzz, just a click. I'm thinking it might be your solenoid. If the internal contacts are worn, pitted, whatever, it might not be letting enough juice through to the starter.

And it is like yours in as much as once it starts to work, it works fine for a while.

 

[64osby]

Re: 1967 Mercury 50 hp buzz noise

Poor connection(s), wire rotting from the inside or the solenoid is pooping out. A buzzing sound is usually low voltage to the solenoid.

Check the connections at the switch too.

Glad it still runs:joyous:

 

[Texasmark]

Re: 1967 Mercury 50 hp buzz noise

Clean up all your connections from the battery to the solenoid, hots and colds. Inside is where you want them clean, not necessarily on the outside as that doesn't help the current flow.

If problem continues then get a new solenoid. When the solenoid engages on some units, the plunger disc rotates slightly. On a solenoid with worn contacts this means that you are trying to put current through a different set of contacts each time you start. If one is really pitted you can find that dead spot where current flow is reduced and you get the problem you have.

Mark