Merc 115 - Blown Out & Further Revelations

[calboats]

Spent yesterday with a mechanically adept club member, and got grilled on my motor problems. Yep !!! It was all my fault, gotta admit it at last. Less than 50 hours and I did myself in. Here's how it got burnt out so soon.

Got the rebuilt (very tight) motor in the fall, cold water ok. Did not add even a smidgeon of extra oil or break in stuff, to help smooth the cyl. walls. Ran it slow for too few 5 to 8 hours to break it in right. Motor seized slightly a couple times when hot, but started again in a couple minutes, water pump looked good so motored off.

Next trip I put in a step warmer plugs for higher altitude lake, forgot and left them in over the winter. Ran good in the cold spring and rainy season till August on a very warm lake. Hot dog, up to 40 mph, cupped prop and cookin.

Full throttle on a 100 deg. day on a small very warm water lake. I guess that was the last straw, and a couple pistons are now 30 and 45 lb. low compression. Some metal plugging up #2 spark plug, so it's toast. Too much "cookin" I guess.

So that is the situation, not much to be done at this point except fix it or get rid of it for parts. I found a suitable replacement, so I think I will try the get rid of it part. Since it was in such super shape overall --till I did it in, maybe somebody can use the lower end, power pack, triple carbs, magneto and XX stuff that is still in good condition?? It is not frozen up, that's a good thing.

Anybody out there have an idea of who might be interested, and what this might go for, or maybe e-Bay?? I would like to think about the other motor while it is available right now. Gotta pay for my stupidity, learn from it too !!

Thanks for your help guys, when I get this right, I'm gonna read every motor post till I get it through my thick head.

Sincere Thanks, Cal Drake

 

[sschefer]

Re: Merc 115 - Blown Out & Further Revelations

Cal, Unless your looking to squeeze some instant cash out of it, I'd rebuild it and learn all about what makes these little gems tick. In the end you'll know exactly how to prevent most types of engine failures and just may have a top notch engine again.

 

[jeff_smith_0423]

Re: Merc 115 - Blown Out & Further Revelations

i second that - if you have the ability to rebuild, give it a shot!

Your narrative about the death of your motor made me cringe

 

[calboats]

Re: Merc 115 - Blown Out & Further Revelations

THat's a good idea, but I have enough on my plate right now. I'm building a 17ft. PLywood lapstrake Chesapeake type sail boat for next year. It has a built in electric Minn Kota auxiliary for power. I'm not so good at mechanical stuff, but I was a jeweler (graduatee Gemologist) for several decades in Los Angeles, woodworking on the side as a hobby. Engines have not been as fun for me, but yes, I should be more aware of keeping them happier a BUNCH !!

To learn, I might pick up a nice older one lunger, not a full size screamer.

I did get a fair amount of response, and I think it will be gone by this week end, or hope so at least. Then I can spend a bunch more to replace that one with a newer, lighter, but less powerful motor. Don't need more than 80 hp on a 17 ft boat anyhow?? However, same brand, same controls and same plugs, easy to do.

Many Thanks --- for all the sympathetic mail, great to know others share the pain , and offer helpful suggestions.

Sincerely, Cal Drake

Cal, Unless your looking to squeeze some instant cash out of it, I'd rebuild it and learn all about what makes these little gems tick. In the end you'll know exactly how to prevent most types of engine failures and just may have a top notch engine again.