average life of a two cycle outboard motor

Hi, I know this may sound dumb but this guy at work swears that the average life of any 2 cycle outboard motor is 750 hours. Is there any truth to this? I, personally don't believe it but don't want to challenge him on this until I get y'all's opinions. Hopefully he is wrong as he is a real know-it-all and can by quite aggravating at times. I would love to take him down a peg or two. Thanks

Re: average life of a two cycle outboard motor

deester said:

Hi, I know this may sound dumb but this guy at work swears that the average life of any 2 cycle outboard motor is 750 hours. Is there any truth to this? I, personally don't believe it but don't want to challenge him on this until I get y'all's opinions. Hopefully he is wrong as he is a real know-it-all and can by quite aggravating at times. I would love to take him down a peg or two. Thanks

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In the 1950s, OMC tested them for a minimum of 1000 hours before putting them into production. Mercury ran them up and down the local ICW here night and day, 24/7, for God knows how long. Hours aren't what kills motors. People kill motors. And water where it doesn't belong. And overheating. And of course salt water. Add a healthy dose of ignorance and stupidity.

Re: average life of a two cycle outboard motor

Wow! that is quite a question and sure to result in many opinions. I have always heard 1000 hours for a 2 stroke and 2000 hours for a 4 stroke. But there are lots of factors that would raise and lower those numbers. A big one is how often the motor is run. If you run it every day for an hour as opposed to occasional use, the life expectancy would go up significantly. Also, you seem to see lots more lower horsepower motors still chugging away compared to the big behemoths of the past. I would suspect that is a factor too. Of course proper maintenance is a key. Usually what kill motors long before their time is some component breaks or corrodes. A cooling problem or clogging carburetor on a multi-carb motor are two main reasons for powerhead failure.

Re: average life of a two cycle outboard motor

There are a lot of 50's and 60's vintage motors out there still running with plenty of life in them. For the sake of argument take a 1960 outboard. That would now be 50 years old. 750 hour divide by 50 years is 15 hours per year. Seems like very little usage for a boating season, even up north. Design life and actual life can be vastly different. I can see this for a weed whacker or chain saw, but it seems light for a water cooled outboard. Rick

Re: average life of a two cycle outboard motor

A 2002 EPA article placed the annual "Average" use of an outboard two cycle motor at 34.8 hours [see page 10: http://www.epa.gov/otaq/models/nonrdmdl/p02014.pdf ]

If that is close to correct, the projection using 750 hours would be 21.55 years, which is not bad in my opinion.

"Average" of 750 hours would indicate that half of the motors lasted longer than that.

I have no idea of the data used in these references or if they are mean or mode.

I think that LeeRoy Wisner got it right: http://www.sschapterpsa.com/ramblings/Most_motors_ruined.htm

See: http://www.epa.gov/oms/models/nonrdmdl/nr-arch.htm

Re: average life of a two cycle outboard motor

I agree completely with F_R.

I don't know how to quantify neglect and/or abuse but I am sure they are the outboard killers.

I did some Training consulting work for OMC in the early 70s. One of their mantras was that a well maintained JohnnyRude outboard would outlive its owner.

For myself, I have never seen a "worn out" outboard of any age and have revived many that were comatose from neglect and abuse.

I doubt that I would be far wrong if I said that a well cared for and maintained outboard will last until something breaks, and if that something is corrected it will last until something else breaks.

Re: average life of a two cycle outboard motor

My take on this.

When I purchased my 14' Lund dlx I needed an engine for it. The boat has a side steer console in it and is rate for a 35hp. Well I couldn't find a nice 35hp short shaft that I could afford at the time but came across a 1964 Rude 18hp on CL. The guy wanted $150.00 and he told me it needed the carb rebuilt. He took $125.oo.

I got it home and just for grins I put the gas to it and tried to start it. It spit and sputtered. Backfired a few times so I quit. Pulled the plugs then ran a compression test. As I remember Iwas getting about 70-72 psi on a rope start. I then rebuilt the carb, cleaned the OLD plugs and tried it again. 3 pulls and she fired right up and just sang. Only she wouldn't idle. Found that the twist throttle was out of position because the metal tag for start/stop wasn't right and the bushings in the linkage were worn out. Then after running it in the barrel for awhile I found that the clutch dog and shift seal were shot.

Well I found another 18hp on CL with a blown cylinder. That guy wanted $50 for it but took $30. and the twist grip because he needed it for another engine. Swapped out the lower units and ran that motor for almost 3 months until I finally found a 35hp.

Now, being as that motor was 45 years old it ran like a top and I could tell it had been used well and not just sitting in someones basement/garage. As old as it was it still pushed that Lund very well. With just me in it I would guess that top end speed was just as fast as the boat is now with the 35 on it only with 2 people in the boat it would slow some and with 3 it would still plane but just barely.

Believe it or not but I sold tat engine that summer for $375.00 and the guy was very pleased with it.

So I believe that even with just minimal care, clean carb, water pump and oil changes these oldies just keep running. BTW, the 35 is a 1978 that came off a pontoon and I have no idea how many hrs are on it but it just runs and runs well.

Re: average life of a two cycle outboard motor

Many many years ago i had a 1957 or so 18hp johnson that i had bought for a hundred bucks to use for cheap fishing!Went fishing up a river at the end of a local lake and on the way out the waterpump impeller went south,well now what to do with several miles of river and a small lake to cross?Owe well its only a hundred dollar motor and im not swimming so i started it and went as far as i could till it wouldnt run any more from heat siezure,and repeat several times till i finally made it back to the dock with the motor smoking and the water litterally boiling around the leg .Took the old girl home and replace the impeller and went to start but it was siezed solid so took out the plugs and got a hardwood dowell and proceeded to hammer at the pistons until they moved again.That motor though i dont own it is still in service today and has never been touched again ,try that with a new modern motor and see where it gets you!Regretted selling the old gal so much i dun went and bought several more,lol.

Re: average life of a two cycle outboard motor

i wpuld say 2000 hours

Re: average life of a two cycle outboard motor

Yep they are long lifers. Check out this thread.



http://forums.iboats.com/showthread.php?t=370228

Re: average life of a two cycle outboard motor

yes, I'm also impressed with the 3 - 7.5hp OMC motors of the 50-60s. Those little motors were the real workhorses, and craigslist/ebay is filled with those little gems.

Re: average life of a two cycle outboard motor

just finished servicing a 1956 10hp, runs better than the new ones.

Re: average life of a two cycle outboard motor

Far too many variables to answer with any accuracy in my opinion. The servicing, respect of use, neglect, stupidity and ignorance play a huge part in it.
My 2 cents.

Re: average life of a two cycle outboard motor

Never have understood why some folks think a 4 stroke outboard will automaticaly last twice as long as a 2 stroke. Anyway, the commercial folks around here get typically 3000-5000 hours out of either. And none of them are in no way easy on any motor. Sure some motors, of either sex, didn't last 750 hours but most do. I for one would be real interested in looking at your buddy's research material.

Re: average life of a two cycle outboard motor

F_R said:

In the 1950s, OMC tested them for a minimum of 1000 hours before putting them into production. Mercury ran them up and down the local ICW here night and day, 24/7, for God knows how long. Hours aren't what kills motors. People kill motors. And water where it doesn't belong. And overheating. And of course salt water. Add a healthy dose of ignorance and stupidity.

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How about Lake X down there in Florida. I saw some pictures of what was done to those engines and you wouldn't believe it.

While I'm thinking Merc ran a marathon with their newly invented then Merc Mark 75 as I recall. I think that is the proper nomenclature for their 60 hp tower. They ran them non-stop and as I recall the "mother ship" would pull up along side, gas her up, install a new driver and they just kept running.

Also know OMC ran across the Atlantic when they introduced their "Fat 50".....50 hp and 70 cu in.....no wonder that sucker could plane out and run a 25' cruiser at a nice clip (25 mph I'd guess) with 6 adults aboard. They admitted that it went with a "tender that lifted the boat out of the water when the weather was bad.
l
Just a couple of days ago a guy bought a Mark 75A and was asking about the remotes.

A couple of weeks ago a guy was completely overhauling a 40 hp Rude that was built in the late 50-early 60 period and you wouldn't believe the shape those parts were in.

So, in good hands, I'd say forever!

Usual irrelevant 2c.

Mark