Looking for insights '75 Merc 65HP "Red Stripe"

[jim j geezer]

Couldn't find a model #
SN: 3149943 <--Confirm it's a '75?

Recently acquired this semi basket case for $75. The ignition/electronic had been removed but were included. Plug wires have been cut, as had the throttle & gearshift cables. The power plug & cable were missing. Aluminum prop looks rough. PO said he thought he detected a hairline crack in the lower unit, although these tired old eyes could make out only scratches in the paint. I was told that it ran fine when it was replaced with a newer 3-cylinder version, but that the 3-cylinder refused to run, so some swapo-chango was done with this engine's ignition/electronics. <--Rookies @ work? Within an hour after purchasing I was visiting with my nearest used outboard dealer intent on brain-picking. The one thing he said that stuck with me was that, "Those 'Red Stripes' were notorious for going through ignition modules."

Assuming I focus on used parts, how much ca$h should I expect to dump into this project to get it running reliably?
1. Cables & control box?
2. Wiring harness & plug?
3. I THINK I can dress and make the prop servicable, but...?
4. ignition/electronics modules?

What kind of quirks should I be alert for?
1. Oddball plugs? (I prefer Champion)
2. Fuel mix?
3. Lower unit lube?

Bonus question: I recently acquired an instrument panel that included several gauges and a tach. Can I use that tach to read RPMs on both single and multi-cylinder engines?

 

[Maxz695]

Re: Looking for insights '75 Merc 65HP "Red Stripe"

no one can give you even a round about price go on ebay and start searching used parts all of what you have listed there should be found or a close match for price comparison. I have an extra switchbox if thats waht you mean by ignition modual not sure if yours has a distributor or not you can message me if you think you might be interested in it. Before you buy anything for it check the compression to see what the number are. No sense fixing up a motor with bad compression. No matter what the PO said you have to check the gears to make sure it shifts properly check the LU oil for water and metal chips etc etc. make sure the major componants are in working order.

 

[Dave1027]

Re: Looking for insights '75 Merc 65HP "Red Stripe"

I'm thinking the first thing to do is to connect a battery to the starter and do a compression test to make sure you have a decent platform before you get more time and money into it. Also, shift the lower unit by hand and check prop to make sure the gears work. Drain the lower unit and check for water intrusion.

 

[jbjennings]

Re: Looking for insights '75 Merc 65HP "Red Stripe"

If it has a red stripe and the red striped cowl is original, then I don't think it's a '75 model. I think the red stripes were late 60's up to maybe '70 or so.
If it's a red stripe, I'd also think it might be a 4 cylinder 65hp. If it has 3 cylinders, it may indeed be a '75 model.
IF a 3 cylinder, they were bad about getting cracked water jackets (I own one that does, and the cracks are all the way from the top to the bottom cylinder under the exhaust cover and held together by jbweld) if overheated. The ignition needs to be set right so you don't get detonation and if a 3 cylinder, it only has 2 carbs and they're hard to get tuned to get a smooth idle under all conditions.

As said, you need to do a compression test and look under the exhaust covers for cracks in water jackets, along with a lower unit check. '75 is pre-stainless drive shaft so finding a good lower unit with no water or rust is unlikely in my opinion.
If the water jackets, compression, and lower unit check out, you need to locate used parts for dirt cheap or it will nickel and dime you to death until it's no longer worth repairing. I would think that the way you describe the motor, that someone thought it was no longer worth fixing and therefore cut the plug wires, etc
You really need to explore before buying anything. The starter is easy to take apart and usually cleaning it up will get it working good enough to check compression if it's not working.
Sorry to be so negative, but you've really got your work cut out for you they way you describe it. I have two of those 3 cylinder 65hp mercs, and they're not my favorite motors. Oddly enough, they do both start easily when cold which is a trait not all mercs seem to possess in my opinion.
Good luck,
JBJ

 

[jim j geezer]

Re: Looking for insights '75 Merc 65HP "Red Stripe"

1st: What's a "switchbox"? It seems like maybe a nickname for an electronic module.

This is a 4-cylinder engine and it does have a distributor. The red stripe around the cowling appears to be original.

EDIT: Not that it matters, but, I was also told by the used outboard dealer that this engine has been the recipient of a long shaft conversion kit - which I intend to remove.

 

[jbjennings]

Re: Looking for insights '75 Merc 65HP "Red Stripe"

A "switchbox" is a battery cd ignition module. I've never owned the 4-cylinder 65hp merc but I hear they're really good motors. Smooth running and powerful/fast.

The engine you describe is, I believe, somewhere between a '68 and '70 model. If it's got a long shaft conversion kit, you may have to locate a short drive shaft at the very least to convert it back.
Crowleymarine.com has some parts diagrams and such to get an idea what you will need.
I think it will be difficult in spite of good compression to get it running reliably with controls for less than 4 or 5 hundred dollars unless someone comes through with some really cheap partrs. Just the controls are likely to cost you some dough on the auction site. A parts motor might be a good idea that comes with controls.
You can cruise the parts and place a free ad on aomci.org as well.
Good luck,
JBJennings

 

[Faztbullet]

Re: Looking for insights '75 Merc 65HP "Red Stripe"

The serial # some it to be a 1971 4 cylinder 65. These where only built for a few years and is a animal all to itself. Nothing internally in motor will interchange with another engine.

Assuming I focus on used parts, how much ca$h should I expect to dump into this project to get it running reliably?

If it weak/low compression $0.... when I get these they go straight to aluminum pile less lower unit.

 

[jim j geezer]

Re: Looking for insights '75 Merc 65HP "Red Stripe"

I now know a bit more, but I'd still like to nail down the vintage. I [mis]described it as "65HP". It's a "Mercury 650". My front cover is black plastic -vs- polished aluminum/chrome. From online reading it seems that '72 was the year Merc went to a 3-cylinder 65HP, so I can safely presume mine is a '71 or earlier.

I made a couple of follow-up observations. (1) The are TWO slender red stripes around the cowling rather than a single wider one.
(2) The electrical receptacle on the outboard has just six pins, but appears as though it would accept a 7-pin connector - two of which I found on ebay. (3) Alas, the wiring from the receptacle is a dried-up and shredded shambles. <--Am I correct in assuming it'll be all but impossible to find a serviceable replacement?
Next I want to check compression and for spark.
Recommended Champoin plugs?

The lower unit DOES have a hairline crack extending from one side to the other around the FRONT! Also the skeg has maybe 1-1/2" broken off. I'm thinking Dura Fix might offer a penny-pinching solution.

EDIT: Based in the SN of my Merc, I'm comfortable tagging it as a '71.

 

[Maxz695]

Re: Looking for insights '75 Merc 65HP "Red Stripe"

If compression is good and the fringes like carbs switchbox Spark there with a homeade wiring set up. shows good. I would fabricate my own after getting a manual or someone send you the schematics for the wiring. Check the basics of the engine before buying anything for it or part it out and get a good engine that you know works. It is very intriguing to get to know outboard engines and the accomplishments you can make but you have to realize the dollar amounts when doing so. Sometimes we win alot of times we lose. Be smart enough to decifer the difference between stepping into a goldmine (Once in a blue moon) or stepping a pile of SHYTE! OOPS be careful