Just how difficult is it to rebuild an outboard?

Outsider

Lieutenant Junior Grade
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Apr 24, 2007
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1,022
Re: Just how difficult is it to rebuild an outboard?

I personally would put 32:1 mix in a motor, like this.

The motor had no maintenance for 31 years, then he ran it to 5200 rpm in the driveway. I don't believe 50:1 oil was an issue ... :facepalm:

Good luck with a rebuild, those were/are workhorse engines ... ;)
 

1946Zephyr

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Oct 21, 2008
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Re: Just how difficult is it to rebuild an outboard?

5200 rpms in the driveway?? Yikes.:eek::eek:
 

wilde1j

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Apr 15, 2002
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5,964
Re: Just how difficult is it to rebuild an outboard?

You can get shop manual, user guides, and parts lists for J/E's back to the year of the flood from outboardbooks.com
 

ONERCBOATER

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Oct 11, 2010
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Re: Just how difficult is it to rebuild an outboard?

the rebuild won't be that bad, follow directions, read manual, take LOTS OF PICTURES as you disassemble it, the pictures are every important, every time you remove something take pictures...two or three from different angles (the joys of digital cameras). You will find yourself referencing the pictures ALOT while putting her back together. make very sure that as you take the rods out that you 1st mark them so that they go on in the same place, and the same orientation both in regards to the crank and to themselves (caps and rods MUST be kept together and in EXACTLY the SAME orientation to ea other due to the method used to manufacture them). I myself clean them off as they come off and mark with a permanent marker, oil pencil, or paint pen stripe to assure they are not mixed up in any way.

The glass sheet check for head and block straightness is very important. On my 15hp johnson when i redid it, one of the reasons it came apart was because it had a head gasket leak, just replacing the head gasket would not have worked or not for very long as the head and block were cut from water and exhaust gasses passing through the leak. I had to remove .015 off of them with a fly cutter to get them straight and make sure they mated correctly.

hmmm wow i can ramble.... sorry guys.

Sean
 

CaneCutter79

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Re: Just how difficult is it to rebuild an outboard?

So I just bought the shop manual. Does this give you detailed step by step instructions? If so, I think I can do this. I'm just affraid I won't know if I will recognize something bad if it were in front of me. I may just have to post detailed pictures and let everyone weigh in. :)

Depending on what I find in the tear down and a rebuild is needed, should I replace all the rod bearings and wrist pins, and such regardless of condition?
 

wilde1j

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Re: Just how difficult is it to rebuild an outboard?

Not if they're still serviceable. The stuff in the shop manual is step by step, but presumes you know basic shop procedures. It's not going to explain how to use every tool, etc. With most rebuilds, the stuff you mentioned above is reuseable, unless metal or water has been flying around in the crankcase.

This place can help, but a knowledgeable friend is even better.
 

CaneCutter79

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May 24, 2009
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454
Re: Just how difficult is it to rebuild an outboard?

Not if they're still serviceable. The stuff in the shop manual is step by step, but presumes you know basic shop procedures. It's not going to explain how to use every tool, etc. With most rebuilds, the stuff you mentioned above is reuseable, unless metal or water has been flying around in the crankcase.

This place can help, but a knowledgeable friend is even better.
Thanks!:D

I took the starter apart and fixed my squealing problem. After I found out how easy it was, I felt more confident about working on the motor. Then I took the head covers off and replaced the gaskets. That wasn't that difficult. It was quite easy really. I get a little over-whelmed with motors but I am very mechanically knowledged.

Knowing I have help hear from multiple folks is a good comfort. Thanks again to all for the replies, support, and insight. I feel confidant that I can get this done after looking at the parts assembly diagram, looking at my current manual, and now knowing I have a shop manual. I can use the tools, it's the adjustments that worry me. I'm betting the book covers this or I'll understand why things need adjusting.

In other words, it's great if you are a certified mechanic to do a rebuild but you don't have to be one in order to do it and do it right. (correct me if that's wrong)

I'm excited about this and ready to take it on. It's going to mean even more to me knowing I did it myself. This boat is a collector's item to me and I love the history of old boats and outboards. Cool stuff!:cool:
 
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CaneCutter79

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Re: Just how difficult is it to rebuild an outboard?

The glass sheet check for head and block straightness is very important. On my 15hp johnson when i redid it, one of the reasons it came apart was because it had a head gasket leak, just replacing the head gasket would not have worked or not for very long as the head and block were cut from water and exhaust gasses passing through the leak. I had to remove .015 off of them with a fly cutter to get them straight and make sure they mated correctly.

hmmm wow i can ramble.... sorry guys.

Sean

Good to know.

Can someone provide a link of instructions on the "glass check" test? How do you sand down the head? By hand? Sander? I assume by hand and very carefully with a sanding block,
 

dehydrated

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Dec 25, 2009
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Re: Just how difficult is it to rebuild an outboard?

on the conecting rod caps its best to use a awl and scratch a line 1 for #1 2 lines for #2 3lines for #3 4lines for #4 v for #5 v1for 6 magic markers tend to fade with parts cleaning and such simple things to do ahead of time to help you remember later reassembly takes alot more time then tearing it down
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Just how difficult is it to rebuild an outboard?

dehydraed has a good idea. The rods have an up and a down, depending on the oiling hole on the piston end. Make sure you replace the rods correctly based on their oiling hole. Your factory manual will guide you through this. Also, the rod caps are mated specifically to each rod, so don't get them mixed up. Usually you will reuse the bearings and the crank sealing rings.
 

wilde1j

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Re: Just how difficult is it to rebuild an outboard?

For the glass deal, get some double thick plate glass, a full sheet of 200 grit open coat paper and some adhesive spray. Fasten the paper to the glass using the adhesive, then using figure 8 pattern move the head on the surface for about ten seconds. If the head is flat, it will have a uniform appearance across the surface. It's easy to see where the head wasn't making contact with the sheet. To surface a head, just continue the figure eight deal until flat. Just maintain light, even pressure while doing.
 

CaneCutter79

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Re: Just how difficult is it to rebuild an outboard?

Thanks guys. I'm really excited about this. Everyone makes it sound so easy and fun. I really like the idea of doing this myself vs. paying someone $2,000-$3,000 for work I could do myself and know more about my motor. Since I intend on keeping this boat for a long, long time, I would rather know more about it and enjoy the experience.

While I'm anxious to get it back on the water and have more fun, I know that I need to do this right the first time and have confidance that it was done right. I will probably get started in a few months and report back. Lots going on at home now so I hope to start this summer.

Since the motor will probably continue to sit up for a while, any advice on what to do when I try to decarb it this spring? I ran all of the gas out of the carb before storing it for the winter, removed batteries, trimmed motor down, and covered the motor and boat. Any "pre-start" things I should do before trying the decarb?
 

jonesg

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Feb 22, 2008
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Re: Just how difficult is it to rebuild an outboard?

Just follow the service manual, off-season storage prep is all there. You forgot to fog it.!
 

emdsapmgr

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Re: Just how difficult is it to rebuild an outboard?

When you decarb the engine, or fog it, you need to inject the aerosol liquid into the carb throats through the straws that come with the cans. That means that you need to pull the airbox cover off the engine at least once a year or more. I drilled 4 small 1/8" holes in the plastic airbox cover. That way, I can inject the aerosol liquid throught the straws, directly into the carb throats. Saves a lot of time....
 

CaneCutter79

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Messages
454
Re: Just how difficult is it to rebuild an outboard?

When you decarb the engine, or fog it, you need to inject the aerosol liquid into the carb throats through the straws that come with the cans. That means that you need to pull the airbox cover off the engine at least once a year or more. I drilled 4 small 1/8" holes in the plastic airbox cover. That way, I can inject the aerosol liquid throught the straws, directly into the carb throats. Saves a lot of time....
Nice tip!

Guess I need to look up what "fog it" means. I think I can find that through searching. Thanks again to all!:D
 

CaneCutter79

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Re: Just how difficult is it to rebuild an outboard?

So what is a ballpark figure on having a machine shop re-bore or possibly just hone the block? Is $200-500 a good estimate depending on damage and amount of work required? Or is it way more than that?
 

jonesg

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Re: Just how difficult is it to rebuild an outboard?

So what is a ballpark figure on having a machine shop re-bore or possibly just hone the block? Is $200-500 a good estimate depending on damage and amount of work required? Or is it way more than that?

Depends on what part of the country you're in and how much work needs to be done.
An average price I see often is approx $125 per hole to have bored out.
It should be done by a marine machine shop who understand how to relieve the ports so the rings don't snag.

Around Boston its $2400 for 4 cyl, $3600 for V6. Complete remanfger.
That includes everything, complete machining, all new pistons, polish crank, new bearings etc etc , test run AND a 1 yr warrentee.
 

CaneCutter79

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Re: Just how difficult is it to rebuild an outboard?

HOLY COW! I got my Service Manual in the mail and it is EXACTLY what I needed. Most all of my questions can be answered within this book. :D
(this is probably where you experienced guys are thinking :facepalm:)

I am surprised at how much information is in the manual. After buying a repair manual thinking that I was getting a service manual (now I know the difference) I didn't know what to expect.

Thanks to ALL for the encouragement and assistance on this forum and this thread in particular. You have helped turn around a bad situation into a fun project for me. I can't wait to get started this spring on rebuilding my outboard. I am very excited about doing the work myself and saving a ton of money. I know I can do this and with the help of the new service manual, I know I am rebuilding with confidence!
 
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