1977 Evinrude 15hp

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mjk

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Picked up a Jon boat today. 2 questions:

a. what are the preferred plugs for these? Guy I bought it from likes Champion, never have run them before. Also, what is the part #?

b. Any harm running Amsoil 2 stroke oil through it? Just wondering if a full syn oil, on an older outboard, would cause issues. Otherwise, I have Mag 1 TCW3.

Thanks.
 
If I recall, the early models of the 9.9/15hp had a problem with the cylinder head design, and OMC came out with an improved head to be retrofitted to those motors.

I'd say anything in an 80's-and-up vintage is a pretty decent motor. When they're run a lot in salt, they have issues with the rubber upper water tube grommet squeezing shut, then you lose cooling. The 6, 7.5, and 8hp models (starting in the 80's) have the same problem.
 
I have a 1984 Evinrude 15 HP electric start. I use Champion plugs and the motor runs great. As for the oil I have been using Pennzoil so I have no expertience with Amsoil. I would think a synthetic would be fine though.
 
anything tc-w3 is fine.
Plugs I've used several all worked fine.

Might want to check out the carb and jet.

clog-jet.jpg


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Those are pre- 77 motors. In 77, they went to CDI ignitions. I had read about the issue you are pointing out.

BTW, where did you copy/paste that info from? I read it earlier in the night.

Originally Posted By: Vern_in_IL
If I recall, the early models of the 9.9/15hp had a problem with the cylinder head design, and OMC came out with an improved head to be retrofitted to those motors.

I'd say anything in an 80's-and-up vintage is a pretty decent motor. When they're run a lot in salt, they have issues with the rubber upper water tube grommet squeezing shut, then you lose cooling. The 6, 7.5, and 8hp models (starting in the 80's) have the same problem.
 
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NGK in all my marine motors, 9.9 to 90 HP, 2 stroke and 4 stroke. But if I were looking at using something different, the last place I'd look for plugs would be the Champion catalog.
 
I love old outboards. I don't know if it just reminds me of my youth and fishing with my Dad or what. Or maybe it was that old Seahorse that he had. I don't know what year it was, but it was old in 1980. I think I just liked the looks of it. Ran great. These things are easy to work on, and it will never hurt to check the jets as mentioned above. I've seen some nasty old carbs, and it wasn't the fault of ethanol. Does the motor have plugs in it? Is there a number? I'd use any TCW3 oil and not waste my dough on Amsoil. Have fun.
 
I have an old viking 5hp about a 1965. its on the back of my old 63 18' with a chrysler 50 on it. The 50hp is a 1965 as well. ngk in both of those.
 
Thanks for the info. I have a quart of Amsoil on hand (I'd never buy it for this application). I use it exclusively for my Ice Auger, so I thought I better use up a bit of it this year. Probably just the first tank.


I typically use NGK plugs, so that was the direction I was going to go in. He claims he had more issues with NGK than Champion, which really struck me as odd. I'll look to see what is in the engine later this week.

So, NGK has the nod?
 
Is the amsoil meant for use in water cooled outboards or just air cooled 2 cycle?
 
Good call. I need Sabre, instead of the Interceptor. Looks like Mag1....

Well, wait..
Amsoil

Originally Posted By: Rand
Is the amsoil meant for use in water cooled outboards or just air cooled 2 cycle?
 
Originally Posted By: mjk
Thanks for the info. I have a quart of Amsoil on hand (I'd never buy it for this application). I use it exclusively for my Ice Auger, so I thought I better use up a bit of it this year. Probably just the first tank.


I typically use NGK plugs, so that was the direction I was going to go in. He claims he had more issues with NGK than Champion, which really struck me as odd. I'll look to see what is in the engine later this week.

So, NGK has the nod?


I'd stick with the previous owners experience before taking a poll here. If he said he always used Champion, and NGK never worked, thats good enough reason to use Champion.
 
An OMC motor (Johnson/Evinrude) of that vintage came with Champions stock from the factory. Prolly J8J or something similar.

I suspect it has manual hi/lo jets that can be tuned with the cover off and the engine running under load. Get a service manual for the motor off eBay and have fun
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They were touting 50:1 back in the day when I was working part time in an outboard shop in Santa Cruz. Put some rings in those motors because they tried to do the factory 50:1 thing and they don't much care for it.

Have much better luck with 40:1 and any TC-W3 name brand outboard oil. I like Quicksilver oil. Can be had at Walmart for cheap enough. For first run with a new owner, I suggest a bit rich on oil for sure. Smoke never killed anybody, but just in case they straight-gassed it during demo or something, get some oil in there ... I'd pull the plugs and spray some Tri-Flow into the upper cylinders. It'll loosen rings that have been sitting and getting gummy ...

So the motor is approaching 40 years old. Mechanically it will be fine unless it's been abused ... As long as the compression is good, the cylinders are prolly fine. But the electrics can get iffy. The old connections tend to get corrosion and oxidation under all the contacts. As the resistance builds up, they start to fry coils. So pop the flywheel off and clean all the contacts and wire lugs. Reinstall all the wire leads with never seize. The screws that hold the coils down are the ground, don't forget those. New stainless star washers would not hurt. Then the ignition should be fine
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50/1 is fine, Post above is referring to when the factory went 100:1 with bad consensuses. Nothing but NGK plugs, and any BIA TCW3 oil is good. Sure you can use up the Amsoil
 
50:1 was not fine in 1974... It might work if you got the right oil. It sometimes did not work out well at all if you did not. Oil was a lot more hit & miss back then than it is today. A lot of folks thought of 2-stroke oil as a throw-away, so they bought stuff at Western Auto and the like.

I still own and run some OMC's from the 1950's, the 1960's, the 1970's (2, 70HP looper and 140HP bubble back) and one from the 1980's. Don't own any Mercury's or Chrysler's (Mariner) or other stuff. Sold the only Honda outboard I ever had. But I do know my way around the odd OMC motor.

If you are running premium 2-cycle TC-W3 and you know the motor has been on it for a while - 50:1 is OK.

A new-to-you motor, with unknown history, no way. Get the thing oiled with at least one tankful a bit on the rich side with known good oil.
 
My 1968 Johnson 55HP came with factory recommendation of 50:1 and we ran that motor 20 year at 50:1 and sold it to a guy who ran it 10 more s and then sold it again. All of the early 70's OMC I owned ran 50:1 and ran forever. Local hunt and fish camp ran oll there 6HP Johnson at 50:1 all day long with no problems. Yes the early OMC ran 16:1 with the split bearings. Those owners today run 24:1 with the better oils today.

50:1 for an out board is nothing. I still see people running Yami's and OMC's at 100:1 (as that was once the factory rec) but that is asking for trouble IMO
 
Understood. But the important point is YOU did all that running and never ran bad oil or forgat and ran on what was in the tank with a top-up with straight gas ... The OP has a motor that is new to him with unknown lube history.

I'll over oil any used motor for two tank fulls, unless I know the history ...

No motor ever died from too much oil, only to little. Let's over oil to flush out whatever was in there and get all the bearings and rings loaded with our preferred before we start running longer runs to remote places and such
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And how does your 50:1 blend work with 10% ethanol? Do you find your favorite to mix as well? Does the alcohol strip any lubricants? What's the best TC-W3 to use with ethanol blends?
 
Originally Posted By: BrocLuno
An OMC motor (Johnson/Evinrude) of that vintage came with Champions stock from the factory. Prolly J8J or something similar.


The factory plugs were champion surface gap plugs (no ground strap) L78V, those plugs have been superceded by the 833 or 833M or 827 or 827M. With surface gap plugs they work best if you plan on running it hard across the lake all day and stopping once you get to the fishing hole. Since they are easier to foul while trolling you can try plugs with a ground strap cold to hot L78C, L82C, L86C work well. add a Q on the front of those last number for the resistor plugs.
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I suspect it has manual hi/lo jets that can be tuned with the cover off and the engine running under load. Get a service manual for the motor off eBay and have fun
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The carburetors on these have adjustable low speed mixture and fixed jet high speed

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They were touting 50:1 back in the day when I was working part time in an outboard shop in Santa Cruz. Put some rings in those motors because they tried to do the factory 50:1 thing and they don't much care for it.

50:1 is the correct mixture to run in these outboards they have needle bearings at the wrist pins and crank shaft pins. They will run 6500 RPM all day with this mixture anything more than that and they WILL foul plugs while slow trolling. If you are worried just remember even the cheapest TC-W3 oil today is still better than any oil you could get your hands on in 1977.

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Have much better luck with 40:1 and any TC-W3 name brand outboard oil. I like Quicksilver oil. Can be had at Walmart for cheap enough. For first run with a new owner, I suggest a bit rich on oil for sure. Smoke never killed anybody, but just in case they straight-gassed it during demo or something, get some oil in there ... I'd pull the plugs and spray some Tri-Flow into the upper cylinders. It'll loosen rings that have been sitting and getting gummy ...

Again 40:1 is probably over-kill for this engine and will probably result in easily fouled plugs if you do any trolling. If you think the rings are gummed up do a decarb and dont be afraid turn this engine 5500-6500 RPM some years the powerband was even listed from 5500-7000 RPM so it will handle it fine if its in decent shape and running correctly.

I have run and worked on a lot of these outboards, they are solid and run very well when you get them dialed in
 
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Guys, please note that I only said to run 40:1 for one or two tank fulls to get whatever old oil is in there used up and fresh known oil all over. Sort of the 2-stroke version of a flush-o-matic
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Yeah, the plug deal is all about how you run it. Surface gap is great for high speed. Keeps the flame pocket closer to the head and further away from piston crown, so less chance of seizing. But they don't troll too well ...

Fine wire plugs (easy to light) with some tip extension troll well, but they move the flame pocket out, so gotta be a bit more careful at sustained high speeds. For the average fisherman or family running around, it's on and off the throttle enough that it won't matter. For a person who has five miles to run and then drifts, I'd be all over the surface gap plugs
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Goinna have the same issue with my new used unknown 140 V4. The ring pack was moved up and these motors are finicky about flame pocket and heat management. If it has good CR, I'll set it up to run 7/8's throttle most of the time, including surface gap plugs. If the CR is iffy, it'll get it set up to cruise and run plugs with ground strap ... Once I know the motor, I can look for a used hull to mount it on. Got my eye on a little 15ft Starcraft beater ... A little transom work and it out to be a Pup. Quick enough to need Kid reflexes
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My '95 Evinrude 9.9 runs better with NGK plugs vs. Champions. I use Quicksilver Premium Plus oil.
 
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