outboard rebuilding, why?

THEFERMANATOR

THEFERMANATOR

God
I did a write-up on another site regarding why you would rebuild an outboard, and what to look for in doing so. thought it would be some good literature for here as well.

This is the question that was asked.

hook -n- haul said:
It appears to me that once people rebuild their outboards, they place the boat for sale. I have some questions about rebuilding that perhaps someone here can answer.

When they rebuild an outboard, what are they actually rebuilding?
What is the life of an outboard once it is rebuilt?
Will a rebuilt engine run as well after the rebuild as it did when it was fine?
How do you know if an engine needs to be rebuilt?

Thanks for the info!
Click to expand...

And this was my response to his question.

I rebuild them, so maybe I can give some insight. There are MANY degrees to a rebuild in the marine industry. ALOT of builders consider honing the cylinders and maybe replacing a piston and a set of rings to be a rebuild. I call this a repair. A rebuild should entail the complete teardown of an engine and evaluating wether or not it is within factory specs. If it is still within specs, then you would normally replace the pistons and rings, as well as all the gaskets and seals and a few of the major wear items inside. this will recondition it to the point of not being new, but being within a factory service tolerances, and should give many more years of use.

A BIG problem with alot of builders is they will go in and fix an engine that is not running right due to an internal issue, and not find out what caused the problem in the first place. MOST 2 stroke outboards don't just fail, there is normally an underlining problem that causes it. Most any 2 stroker should be good for 2000+ hours, but many have reported 7000-8000 hours. But a simple issue like not remembering to fill your oil reservoir can ruin an engine in a hurry, or a failed water pump impeller can cause imenent doom as well.

I personally like to remanufactur an engine when I do them. Most of my engines when I tear into them are worn out beyond factory service specs. SO I will completely disassemble, inspect and measure, and then determine what needs to be done. If the cylinders are out of round from wear, or to large I will have them bored to the next up oversize. And I am very anal in the fact that I want ALL of the cylinders to be the same size. I WILL NOT put in different oversize pistons in each cylinder, many people will only bore the ones that are out of spec. I will also replace all of the rod and wrist pin bearings, and many times replace the lower main bearing and upper. I will also have the heads surfaced as well as the block mating surface to ensure a positive seal. Many times a remanufactured engine if done properly WILL run BETTER than new since you take the time to ensure all measurements are EXACT instead of within an acceptable range.

This is where the LARGE price differences come into play with different shops. It comes down to wether they just repaired them, or remanufactured them. And you don't always get what you pay for, I just tore an engine apart today that has less than 10 hours since a rebuild by a large shop in TAMPA. IT IS FUBAR inside, so remember to find a reputable builder.
 
:clap:



Ferm, that loks allmost identicle to an answer I gave on the same subject on another forum. Somehow, people get the idea patched, or repaired is the same as rebuilt. When I first started working on outboards, I had been working on I/O and automotive engines for years, I was astonished that people would rebuild an outboad boring only one hole, I would have never tried on an automotive engine(allthough there are some that will). there are very few people that actually rebuild an outboard the way its supposed to be done, as you pointed out. Done correctly, a true rebuilt(remanufactured) outboard power head should last as long, if not longer than it originally did, given the rest of the engine is up to par. Most people just don't want to spend the money it takes to do it right
 
I did this write up on the FLORIDA SPORTSMAN forum. After the origanal poster asked the question, several posters jumped in and they ALL said a rebuild will NEVER be as good as it was when new. I take pride in building an engine when I do one. And NO they don't run as good as they did before, for the firs few hours. Once they get broke in ,they run as good or better. My 140 EVINRUDE looper was my first 2 stroke to actually rebuild(not just repair). It would tach out at 5200-5300 on a good day before building it, after it needed a new prop because it would SLAM the 6100 limiter. Alot of myths out there floating around.
 
Ferm, if you lived closer, I would be at your house about every afternoon or weekend.
Honest to God there isn't that many reputable outboard mechanics around.
Biggest problem is they just don't know.
What is worst, they don't know that they don't know.
 
I'll be the first one to admit I don't know it all. I learned humility awhile back. the difference is I WILL find out. ALOT of people out there in the industry think they know it all.
 
Carburetor???
Oh I've heard of them.
If they can't diagnose it with a machine, it can't be fixed.
Jackasses last year replaced $700 worth of catalytic converters (4) on a truck of ours because the machine said so.
Afterwards I found the real problem, a busted harmonic balancer.
$69 with shipping.
 
I once looked at a car a guy had for sale, he said he had "rebuilt" the motor.

I opened the hood and the motor had obviously never been touched so I asked him what all he did during the rebuild.

He said he had done "everything, you know spark plugs, plug wires, changed the oil, new points (it was a while back)".....he honestly thought that he had rebuilt the motor.

As for those who say a rebuild won't be as good as the original, any decent hot rodder will tell you they are wrong......if its done right.
 
i like how you work ferm with checking the tolerances. honda with their outboards are fanatics about tolerences and balance, they kept them tight. also incase anyone was wondering, what ferm does is called blueprinting the engine before building. if you buy a blueprinted engine which is overhauled then like said before should run better than before. especially if its a 90's omc before BRP took them over.
 
To me a standard rebuild involves checking all the tolerances, you oughta see me blueprint an engine. I break out all the fancy micrometers and dive in. I build my performance engines to some strict tolerances. I can normally tell a thousandth or 2 just by feel and looking at them, but when I want em right I break out all the neat toys:oh:.
 
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