1966 Merc 500 50 hp won’t fire

[GlassmasterWV]

Recently acquired this Glassmaster Bonita 500s in what appears to be really nice condition. Engine looks hardly run, and boat has been dry stored it’s lifetime.
I’ve hooked a new battery up and put fresh fuel mix in 6 gal tank. Motor seems to crank but won’t fire. I changed the spark plugs and still nothing. I’ve got video of trying to and the propeller is turning. Have thought about it being in gear but as far as I can tell I have it in neutral.
Anyone have experience getting a nice old engine to fire? Here’s some video:
https://youtu.be/hc4tXg_pd5Q

Thanks for having a look!

 

[GA_Boater]

Welcome aboard.

Yes I got one to run.

You aren't in neutral, the prop doesn't turn like that in neutral.

I see the warmup lever is raised. Are you choking and and squeezing the bulb until it's hard?

 

[jimmbo]

Does it have spark?

It looks more like a 1965, not a 66

 

[GA_Boater]

Does it have spark?

It looks more like a 1965, not a 66

Yep wrong decals for a '66. A '66 has a fire-prop, not stars on the lower cowling.

I think is sparking cuz it kicks every once in a while.

 

[GlassmasterWV]

Good catch! The boat is a ‘66 (per title and original owner), and the Merc is a ‘65, bought with the boat.

The last time the boat was registered and in water was 2002. Original owner said he always detached fuel line from engine and let it idle until it quit.

I pulled the manual choke up on the on the top of the motor and the primer bulb was squeezed until hard.

Is there a way to tell of it is in neutral?

I appreciate the fast response.

 

[Tassie 1]

It's cactus...
kaput...
knackered...
had the richard...
you broke it...

don't listen to those blokes,
they'r

send to to me...at your expense of course...just the donk, don't need the boat
and l guarantee it'll have a nice retirement spot in the shed in the boating capital of Australia,

Tasmania...
you'll need the postcode,
got a pen?

 

[GA_Boater]

Don't send the motor anywhere! :facepalm:

Put the shifter in neutral, there should be 2 raised lines in top of the control about the width of the throttle lever that marks neutral. Make sure the key is off, in your pocket is best and try to turn the prop. It will turn left and right with no resistance. If it is in forward, it will lock in one direction and click in the other. Reverse locks in both directions.

 

[Tassie 1]

Party pooper,
l was that cl...
lol

 

[Vt MercMan]

This is pre-CDI/Thunderbolt ignition so uses a magneto system with breaker points. I never heard the engine fire in the video and doubt it has spark.
If you can find a dealer that’s been around awhile, they will have the correct tools and know-how to correct this. There is a specia plate that is used to set up the points/dwell on those mags.
Good. Luck, when everything is right on those old 4cyl 50s, they idled down better than most fishing motors.

 

[GlassmasterWV]

I just went out and checked on neutral. I had the throttle lever in the two raised lines. I pishednit all the way forward and the propeller did as you described; lock to the left and clicked to the right. I put it back in neutral position and propeller turns both ways.
I did not put it in reverse, as I keep reading never to do that without the engine running.

Back at it in the morning.

Don't send the motor anywhere! :facepalm:

Put the shifter in neutral, there should be 2 raised lines in top of the control about the width of the throttle lever that marks neutral. Make sure the key is off, in your pocket is best and try to turn the prop. It will turn left and right with no resistance. If it is in forward, it will lock in one direction and click in the other. Reverse locks in both directions.

 

[GA_Boater]

I had the volume too low and saw the slight shake as the starter shut off, not popping.

I guess you squeezed the primer bulb until firm? And mine doesn't spin the prop like that in neutral on muffs.

Thing about shifting into reverse and the motor not running is don't force it. If it doesn't go in easy, turn the prop a little. The gear teeth have to be lined up, so a little trial and error, but don't force it into reverse.

You don't need any special tools like plates to set up the magneto. I've taken mine down to pieces and it' the easiest ignition system in the world.

Go get a less than 10 buck spark gap tool at an auto parts store and make sure you're getting spark. While you're there rent a compression tester for free at many stores. So check your spark and compression first.

 

[racerone]

Pull the bottom half of the magneto off.----Just 4 bolts.----Clean and set the points to 0.010"----Careful as the plastic parts are expensive.----Timing looks after itself.----Test for spark before re-installing.

 

[GA_Boater]

Pull the bottom half of the magneto off.----Just 4 bolts.----Clean and set the points to 0.010"----Careful as the plastic parts are expensive.----Timing looks after itself.----Test for spark before re-installing.

All the magneto parts are expensive. :blue:

It is really tight quarters dropping the mag on a 500. Be careful.

The shaft has blank spline, so it's impossible to get the timing off.

The testing for spark while the magneto is off - Use the spark gap tester mentioned earlier. Plug the tester into a plug wire cap and clip the clip on the magneto metal body. Then spin the shaft with a small gap on the tester. Check all four wires.

A word of caution - Don't touch the stud on the side while spinning the shaft or you won't need a spark tester.

 

[GlassmasterWV]

Thanks for all the advice! I’m googling and YouTubing like crazy. I’ve got decent mechanical skills, but I’m a bit rusty and have never worked on marine engines.
Goong to try and check the magneto tomorrow or Tuesday. Anyone got a service manual for a ‘65 Merc 500?

 

[jimmbo]

Not factory manual
http://162.144.28.33/lib/mercury/man...-115.html#/494

http://162.144.28.33/lib/mercury/man...-115.html#/168

http://162.144.28.33/lib/mercury/man...-115.html#/222


Front cover
http://162.144.28.33/lib/mercury/manuals/mercury_1965-1989_40-115.html#/0