Make it Last

[Ron Burgundy]

My outboard motor isn't exceptionally special. It is just a modest Yamaha 50HP 2stroke that was manufactured in 2004. It dosen't push my pontoon boat too fast. Maybe about 19 mph at the top end, but it does get me to where I want to go, and only sips gas (and oil). Whether it is the local fishing spot, or sandbar island several miles offshore it gets the job done. It has about 425 hours on it which equates to roughly 60 hours per year. I have considered upgrading to a more powerful motor, but a new outboard will cost me more than I paid for my boat so I have cancelled any plans to swap out for now. I just want to keep this one in tip top shape, and maybe someday I'll upgrade to a faster, and more powerfull boat.

My question is - What can I do to make sure this motor lasts as long as possible?

Any answer will be appreciated. Dosen't matter if it is about maintenance, driving habits, additives, etc....

[rrhodes]

I would say with 425 hours on it and you are not having any issues keep doing what you are doing.. As with any motorized item I own I follow the recommended maintenance in the manual and I have yet to replace a motor. Usually it is everything around the motor that begins to fall apart and the one marine engine that failed was due to poor maintenance by the previous owner.

[Ron Burgundy]

I am the third owner, but it isn't having any noticable problems. My marina offers a 100 hour service that pretty much replaces anything that is normally replaced during routine maintenance. It costs about $400, but I am considering doing it just so I know where I stand on all my replaceable parts. I purchased the boat in September of last yea,r and the owner told me that the motor was recently serviced, but I don't know exactly what was done.

[margaritaman]

Ron, Leaving your boat in salt water one of the problems is rust so hose down that motor and flush it after every use and store it tilted out of the water. Make sure you have a water separator filter and put an additive that will dilute the alcohol on fuel. I had to rebuild my carbs twice in two years because of water in the fuel tank but my yammy is over 20 years old and still running. I am using more oil so I check and clean my plugs on a regular basis. Replace your water pump every two years before they fail and also change the lower unit gear oil yearly and see it it is getting getting that milky color.

[rrhodes]

Hmmm. My 100 hour service includes Plugs, fluids and filters, Not sure if you like to turn a wrench but most of the maintenance items on an outboard are pretty easy to do and you could take the $350 you save and put it in a "Buy a new motor later" jar... With my 4 stroke the only thing I plan on letting the dealer do is the timing belt when it is time.

[lakerunner696]

Use Seafoam to keep combustion chamber clean. I used to use Powertune but seafoam does it just as well and you never know it's there

[GregF]

There is really no big trick to the timing belt but you need a wheel puller to get the flywheel off. On my Merc it is a regular puller like you use on the harmonic balancer on a car. (3 bolts in the flywheel go into slots on the puller) I think it was about $10-15 bucks at NAPA.
The older generation of Yamaha Merc 2 strokes used a proprietary puller that used a 36mm (?) sleeve into the center of the flywheel.
It is worth a look. Other than that, you just line up the timing marks, following the directions in the book and double check it a few times before you crank it over. I think these are non-interference engines but yours is a Honda so I wouldn't bet my valves on it.

My belt was OK when I replaced it and I was real careful not to move anything (after I had it turned it to match the book pictures of the mark alignment) so it was pretty easy to do.

[Ron Burgundy]

When are you supposed to replace the timing belt?

[GregF]

Ron, you don't have one

[Ron Burgundy]

Ummm, yeah I knew that. Just testing you. Congrats...you passed.

[jrolin1]

Ditto the Seafoam to keep carbon down. I do a decarb using Seafoam on my marine engines.

[Ron Burgundy]

Ditto the Seafoam to keep carbon down. I do a decarb using Seafoam on my marine engines.

Do you just add it to the fuel tank? The owners manual says to use something called Ring Free Fuel Addative. Is that basically the same thing?

[Ron Burgundy]

I found this video online. It was pretty informative for me. Probably old news for most of you all though.

[GregF]

The power heads of those old 2 strokes are usually not what you have to worry about. I put well over 3000 hours on my Mariner 75 (Yamaha design similar to yours) and never had an engine problem beyond the regular tune up items, plugs, carb kit etc. The problems were all in the screw on parts. I had to rebuild the tilt trim, the bolts holding the engine to the bracket rusted out, bad stator, several bad relay/solenoids. I also had a seal go bad in the foot but it was on top so I did not need to go inside. On a merc style foot you can replace the drive shaft and shift shaft seals from the top.

[jrolin1]

Ditto the Seafoam to keep carbon down. I do a decarb using Seafoam on my marine engines.

Do you just add it to the fuel tank? The owners manual says to use something called Ring Free Fuel Addative. Is that basically the same thing?

Yes. Ring free is good also. This is Dunk's (a poster on other boat forums) decarb in his own words. It is what I do every other year.
This works for Carbed, EFI, Ficht, HPDI, Optimax and even 4 strokes...


Dunk:
First you need a separate small fuel tank. One of those 3 gal red Tempos works great or an empty gal milk jug will also work, but might be a bit messier..
I use Seafoam over the OEM stuff like OMC Engine Tuner or Merc Power Tune because in the last few years they changed the formula and you have to let them sit up 12 hours. Who's got time for that?? Seafoam you can buy from NAPA, CarQuest or other auto stores. Seafoam works in 15 mins.
You'll need 3/4 gal of gasoline and one 16oz can of seafoam for each engine. Don't forget to add 3oz of oil if you are premixing in a carbed engine. Use about 3 ft piece of fuel hose off the little tank. You connect this tank to your engine by pulling off the main tank fuel hose off the intake side of your water separating fuel filter and plug the hose off the small tank on to that fitting. Or you can separate the fuel line on the tank side primer ball, so you can still use your primer. If you have an engine that has fuel plug then you need a fuel plug on the little tanks hose.
Start the engine, let it warm up and start pulling the mix into the engine. You may have to increase the idle to keep it running once she get loaded with the Seafoam. Run the engine 15 mins in the dock or just cruising around under 2500. Then shut it down and let it sit for 15 mins. Restart the engine, the smoke you see is the carbon burning off. Do the whole thing again and let her sit again for 15 mins. If she smokes after the second time do it again, but I've never seen one still smoke after three doses. The gallon mix should be enough to do this 3 times. You don't need any wide open throttle, you don't need to change the plugs. If it's cleaning the combustion chambers it's also cleaning the plugs, but every 50-60hrs is good time to change plugs in most engines.
I cleaned a antique evinrude one time that had a 1/4" of solid carbon on the exhaust chamber walls by running a 1/2 gal of the mix through it. Seafoam has been around since the 30's and it's what they used when they were burning straight 4 stroke 40SAE oils in outboards.
You guys with the 4 strokes think you are immune from this? Those engines work 10 times as hard as any auto engine ever will and they will carbon up. I bought a Bronco two years ago that had 95,000 miles on it. When I used seafoam on it I had the neighbors hanging out of their front doors looking for where the fire was after I started it the first time there so much smoke.
Too many are under the assumption that it's totally the 2 stroke oil that causes the carbon, Wrong... it's also the additives they put in the fuels today. The carbon inhibitors in 2 stroke oil are there for this reason also. Remember when gasoline used to smell like gasoline, today it smells more like bad cologne.
For those guys that like to do the carbon treatment by spraying it down the carbs Seafoam also comes in spray can called Deep Creep. It's the same stuff under pressure. Says right on the can Oxygen Sensor Safe, for you Yam guys. After that if your engine maunf recommends a daily additive treatment then do that in the mean time, but all 2 stroke outboard need decarboned every 50-60hrs. If I owned a 4 stroke I would do it the same. Once you are set up with the tank and hose the Seafoam is only 5-6 bucks can. It to easy not to do it.