merc 500 points & timing

[Todd j]

Hi, new here and to outboard wrenching in general!

I have a 50 Hp merc SN 1855838, it is a 4 cylinder.

The boat was given to me and had always been a hard starter. I rebuilt the carbs and on the first real shake down run it started dead cold on the first pull! I was amazed and quite proud of myself as it was a real pain for my brother who had it for several years. I took it out on its first outing last week.

It ran like a top until we were a mile from the ramp at full steam it just crapped out like all the plug wires were ripped off. Here is where I am at now. It does have a weak spark with the plugs out and grounded to the power head. I have the dizzy/mag out for R&R. It appears the breaker points dont open. I searched and found a spec for .008"-.010" points gap. Will this work for me? What is the proper way to file or emory the points to keep them square with each other.

I found Clam's post re: timing and am anxious to get out on the water again! thanks for the help in advance!

Todd

 

[Laddies]

Re: merc 500 points & timing

Save yourself the trouble of trying to clean the point, spend the $40 and get a new set. Gap them at .010 or 48 degrees on a dwell meter and it will last for years

 

[Todd j]

Re: merc 500 points & timing

Got the breaker points today! Marine store said No at .010". They said .018"-.021".

Any suggestions? Only wanna do this once?

 

[Laddies]

Re: merc 500 points & timing

I've been put them in for 45 years set at 48 degrees which is .010, how many sets has the counterman installed?

 

[Todd j]

Re: merc 500 points & timing

Good question? I would feel better if he could have provided a spec from literature. I am new here so I know no one. From your profile and participation here it sounds like you know "stuff".

In my searching here I found references to gapping the points wide to allow for wear. This sounds silly. I know from my auto experiences that points wear and should be checked/changed periodically. Approx how many hours of run time, before the next regap?

Thanks for the help! I look forward to wrapping this project up.

Todd

 

[ThumbPkr]

Re: merc 500 points & timing

I always set points wide to allow for wear but it is the wear of the rubbing block on the rotor that I am accounting for.There should be a lubricant added to the contact area to minimize wear but this has always worked for me.When I say "wide" I mean to set them on the high side of the tolerance scale which would be .018" of the settings published such as .014" to .018" for a particular application.
If you are installing heavy duty points in a distributor without lubrication on the rotor they will wear down pretty fast.Ron G

 

[Todd j]

Re: merc 500 points & timing

I can see that. I tend to shoot for the middle-ish an split the difference. Laddies says .010", so I am guessing he means just that. It all falls back, to this. This job is a PITA and I really dont want to do it again in 6 months!

Todd

 

[Chinewalker]

Re: merc 500 points & timing

Set them at .010", as per the book. .018" is WAY too wide for the 4-cylinder magnetos. .018" is the spec for 2-cylinder under-the-flywheel Phelon style magnetos. Your motor has a Kiekhaefer magneto and needs to be set to 48-degrees dwell, which .010 will get you very close to...

- Scott

 

[Chinewalker]

Re: merc 500 points & timing

Todd,
If you PM me your e-mail address, I can e-mail you a print out for the OEM dwell plate used in the manual...
- Scott

 

[thunderbolted]

Re: merc 500 points & timing

I don't know the exact site, but the company Fluke, that makes multimeters has a link about toubleshooting older outboard magneto systems. I could't get my '60 350 thunderbolt to idle decently, or have a healthy spark, and went step by step through their diagnostics, until every value matched their recommendation and it starts first pull and runs like a dream. Check it out. by the way, I cardboard buffed a 50 year old set of points to their specs.--replaced NOTHING.

 

[ThumbPkr]

Re: merc 500 points & timing

Here is a video from the "Marine Doctor" guy showing an overview of troubleshooting an ignition system with a DVA adapter and an analog meter.
It is very basic but will help in asking the right questions in the troubleshooting process.Ron G
http://www.youtube.com/watch?v=GP7ni_MEkH4

 

[Todd j]

Re: merc 500 points & timing

Sent PM Chinewalker! I will check the Fluke link. I actually started mine on the first pull too after some general TLC stuff. The more resources I can pull together the better off I will be. I will check the you tube deal also.

 

[thunderbolted]

Re: merc 500 points & timing

Worth reading!

http://assets.fluke.com/appnotes/electricalpower/B0271b_u.pdf

 

[gonelong]

Re: merc 500 points & timing

Worth reading!

http://assets.fluke.com/appnotes/electricalpower/B0271b_u.pdf

Excellent.

I have been saving each of these PDFs and/or making PDFs out of the advice I have collected on this forum. I have put together a nice little maintenance CD (and 3 ring binder) from these types of artciles. Some of them apply directly to what I need, some apply to OB's my fishing buddies own.

Thanks for posting, great addition to my collection.

GL

 

[thunderbolted]

Re: merc 500 points & timing

GL,

I notice on your to do list that repairing the reverse lock-down is in order--on my list too. When I pulled the lower unit on my '60 35ph, (not sure it had EVER been off!!) there was so much corrosion around the shift shaft and reverse lock mechanism it was hard to tell what parts were even there. After cleaning it all and unclogging and enlarging the two small water drain holes in the lower unit, I still can't seem to get enough throw from the two brass cams that lift the lock-out shaft. Do they just sit on top of the casting where the shift shaft seal is or is there a spacer underneath? Also seems like just lengthening the rod up to the hooks might work? Any advice much appreciated. Paul

 

[gonelong]

Re: merc 500 points & timing

GL,

I notice on your to do list that repairing the reverse lock-down is in order--on my list too. When I pulled the lower unit on my '60 35ph, (not sure it had EVER been off!!) there was so much corrosion around the shift shaft and reverse lock mechanism it was hard to tell what parts were even there. After cleaning it all and unclogging and enlarging the two small water drain holes in the lower unit, I still can't seem to get enough throw from the two brass cams that lift the lock-out shaft. Do they just sit on top of the casting where the shift shaft seal is or is there a spacer underneath? Also seems like just lengthening the rod up to the hooks might work? Any advice much appreciated. Paul

I wish I could give you some advice, that still sits firmly on my TODO list. I haven't really looked at what I am up against for a month or more. I have a 25% chance of taking Monday off, which I would then look at it. If not, I think early December is the next time I'll have to work on my Outboard, and I'll probably be winterizing at that point.

My "hooks" curl around the bar when reverse is engaged, its just not quite enough to lock the engine down. I replaced my water pump and impeller earlier this season, and I may have caused this myself. Hopefully I'll get a chance to drop the lower unit and figure out what is going on.

I'll have two more weeks of vacation available next year. I am hoping to get these few things on my list completed and find myself out on the water with those days.

If I get a chance to look at anything, I'll make sure to post back on this thread.

GL

 

[gonelong]

Re: merc 500 points & timing

If I get a chance to look at anything, I'll make sure to post back on this thread.

GL

I haven't got a chance yet, but it looks good that I'll get a few shots at it over the next week or two. Would love to get that fixed and get the boat winterized. I'd be ready to fish from the get-go next year.

GL