Where are you guys learning this stuff?

[Cheeze]

Hello everyone. After reading these forums for like three weeks I have finally registered and I'm hungry for knowledge. I recently bought an old fiberglass v-hull boat with a 115 Evinrude and trailer for $350. I knew the motor was trashed but as the biggest engine guru I know, I thought I would give this a try anyways for the price. I'm working on a mechanical engineering degree and anything that has moving parts and needs fuel fascinates me. What I want to know is where all you guys have learned so much information on marine engines, specifically OMC outboards. I've rebuilt automotive engines and have extensive info reguarding thier operation and function. My new old '74 Evinrude has a badly scratched bore and a trashed piston and head. I have the OMC repair for that year engine in the mail and I've found customizable rebuild kits for $500. But is there a website or good book that dives into the works of evinrude/johnson V4's? All I know is from searching forums. <br />Also time investment aside, is that old engine worth rebuilding at all? Is the OMC manual a good enough guide for a marine newbie? My marina has an '82 115 for a grand. I consider the rebuild experience to be worth it to me because it's interesting, but are there lots of special marine tools required? I've redone 3 very old outboards when I was a kid with no help and now I'm moving on. Any direction for good OB info much appreciated.

 

[wilde1j]

Re: Where are you guys learning this stuff?

Most of us gained their knowledge from working alongside knowledgeable people, some from mfgrs schools or trade schools. No easy way I know of. <br /><br />To tear down that powerhead, you will need a puller for the flywheel (harmonic balancer puller with some GR8 bolts and washers will do fine). The OMC book should provide most all the info you will need. Make sure when you get the block bored for oversize pistons that you deal with a shop which does outboard blocks on a regular basis AND make sure they know exactly what pistons (make and oversize) you will use. Also, make sure you know why the PH failed, or you are likely to see the same failure again. If in doubt, post pictures here and ask for help. Good luck.

 

[Walker]

Re: Where are you guys learning this stuff?

The Internal Combustion Theory of a 2 stroke is relatively simple. I learned by working along side an old OMC mechanic foe about 4 years til he died, reading, and just plain old tearing into a couple.<br />Then OMC decided to add stuff like recirculation systems and ignition systems that are hard to dianose. Every thing falls back to proper fuel/air mixture, good compression, and good spark at the right moment. <br />Now more and more engines are being regulated by computers just like car engines. I'm lost there.

 

[djzyla1980]

Re: Where are you guys learning this stuff?

I agree walker.... Thats why I prefer working on older engines...auto or boat. Less complex. I was well shocked in remeberence when I dumped off the newer van and got a $200 75 Chevy truck... Can rebuild the engine without pullin the block, Sit on the wheel wells... and work on it. Now there filled with sensors, wires computers and all that other crap. <br /><br />I have learned quickly... about marine engines, just about asking questions and doin it myself. You learn quickly the mistakes you can make. Get an actual manual for the specific engine. I have one thats for a range from clymer and it sucks... told me that "because of the tools involved and complex location of the water pump it is best to take it to a mechanic to have it inspected" Um... 9/16 and 3/8 yeah... thats special...lol

 

[Walker]

Re: Where are you guys learning this stuff?

And a good memory (which I no longer have)

 

[Goodoleboy]

Re: Where are you guys learning this stuff?

You have to learn from other peoples mistakes. You will never live long enough to make them all youself.<br /><br />Good Luck!

 

[clanton]

Re: Where are you guys learning this stuff?

My learning about engines started with the Air Force 55 years ago, still learning. Last factory training Jan 2005, and hope to make a few more. I have OMC manuals and service bulletins from about 1983, you need info.

 

[imported_Curmudgeon]

Re: Where are you guys learning this stuff?

My marina has an '82 115 for a grand.<br /><br />I think you should let your marina keep it unless it has a brand new powerhead (not rebuilt, brand new!). NADA says around $325 ... you do the math.

 

[papasage]

Re: Where are you guys learning this stuff?

<br /><br /> power head i just got through with . there are several years that has the same pistons . on my 70 1974 the newer pistons would work but had to change wrist pen berrings to put the newer pistons on it.best i can remember they are 3 inch pistons in the 70hp 1974. i have several i bout a box of aol parts and the pistons wer shot <br /> to remove the piston put in a pot of boiling water and when it gits hot the wrist pen wil push out .

 

[Solittle]

Re: Where are you guys learning this stuff?

Cheeze - A big welcome your way!!<br /><br />Here is a thought - Pick up the 82 for whatever you can get them to come down to. Put it on your boat and enjoy it. Then do a rebuild on the 115 in your spare time. When you get done sell one or the other to cover some of the costs.<br /><br />Before you commit to the 115 take it to a marine machine shop and get them to go over it & give you an estimate. While they are doing that put together a list of what else needs to be done to the 74 with cost estimates. Then you can decide whether to go ahead or part it out.