Runs fine, goes no where(2001 4hp johnson)

robert53a

Petty Officer 2nd Class
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Dec 27, 2007
Messages
181
Hi, I've studied the posts search to avail on this subject, I have a 2001 Johnson 4hp that was given to me with this problem. The crank spline is stripped and rusted out so the prop no spin. The lower leg was dropped to confirm this. the motor runs fine, excellent actually. After seaching the posts the only fix is a new crank. OK but before I lay out $270 for a new crank, I've got a couple of ideas. I want to bore out the splines in the old crank and press a threaded inset into the end. Turn the splines off the drive shaft and thread it to match those of the insert. would this work? or is it too wild of an idea? I have access to a first rate machine shop. Any thought by those out there will be greatly appreciated. Thanks.....Robert
 

solar7647

Lieutenant Junior Grade
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Apr 23, 2009
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1,218
Re: Runs fine, goes no where(2001 4hp johnson)

Well you could do alot to fix the issue incuding all the machineing you discribed, but what you realy need to do is think if the possibliity of it failing when your on the water is worth it.. When it comes to your engine just get the part and fix it the way it should be. I am not trying to bash your skills but being stuck out on the water with boats flying by you why your dead in the water isnt worth it. There are alot of stupid people out there with boats. I suggest spend the 270 and make it right.

good luck with what ever you decide!
 

mla2ofus

Chief Petty Officer
Joined
Dec 30, 2008
Messages
571
Re: Runs fine, goes no where(2001 4hp johnson)

My only worry would be getting it loose to change water pump impeller. And if the engine ever kicked backward real hard. Better put lots of antiseize in those threads and hope for the best.
Mike
 

kenmyfam

Supreme Mariner
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Aug 10, 2006
Messages
14,385
Re: Runs fine, goes no where(2001 4hp johnson)

Got any photos of the offending items to review ??
 

ENSIGN

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Jun 21, 2009
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1,179
Re: Runs fine, goes no where(2001 4hp johnson)

It's gonna leave you stuck,use it for a anchor
 

rolmops

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Feb 24, 2002
Messages
5,299
Re: Runs fine, goes no where(2001 4hp johnson)

You could possibly do this machining job,but before getting into that level of repairing,it would be wise to find out what caused the stripping of the crank.
These things do not normally happen and my bet is that the lower unit had a role in this happening.
It might be a better idea to spend your $270 on another 4 horse engine of similar make and use this one for parts.
 

robert53a

Petty Officer 2nd Class
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Dec 27, 2007
Messages
181
Re: Runs fine, goes no where(2001 4hp johnson)

Hi, thanks for all the comments. I took some pictures but was unable to drag and drop my jpg file in post.(about the limits of my computer skills) I pulled the power head for look the splines are totally gone except a hint at the top. when i droped the lower unit the o-ring at the top of the drive shaft was missing, which explains how it happened. i'll keep trying to find out how to load my pictures, so you guys can see what is going on. i appreciate all advice, but it look like putting in a new crank is the only answer.......robert
 

robert53a

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Dec 27, 2007
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181
Re: Runs fine, goes no where(2001 4hp johnson)

hi I'' try the pictures
 

robert53a

Petty Officer 2nd Class
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Dec 27, 2007
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181
Re: Runs fine, goes no where(2001 4hp johnson)

This driving me nuts will not let up load.....Robert
 

bktheking

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Jul 29, 2008
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Re: Runs fine, goes no where(2001 4hp johnson)

You need to post them on a site like imageshack.us, the pics are simply a URL that redirects to a hosting site. Once you upload the site will provide you a link, click on the insert image icon on this site and paste the url, make sure there is only one http:// reference in your post.

Resize to 640x480
 

1946Zephyr

Vice Admiral
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Oct 21, 2008
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Re: Runs fine, goes no where(2001 4hp johnson)

This driving me nuts will not let up load.....Robert

Your file sizes are probably too big. You'll have to open them up with a photo editing software and get them down below 100Kb.;)
 

robert53a

Petty Officer 2nd Class
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Dec 27, 2007
Messages
181
Re: Runs fine, goes no where(2001 4hp johnson)

robert53a
 

solar7647

Lieutenant Junior Grade
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Apr 23, 2009
Messages
1,218
Re: Runs fine, goes no where(2001 4hp johnson)

Ok...make sure the photos are less then 143kb..
you can do this by right clicking on them and going to properties. If the they are larger you will need to open them in Window photo editor and resize them.

Once they are to size log into iboat find your thread and post replay...
when the replay page comes up so you can type find the paper clip icon on the task bar for the typing window..it is next to the font and smiley face.

Click the paper clip...a separate window will pop up.it will say upload from computer and upload from URL. click the choose file button under upload from computer...

find your photo and click ok..

it will take you back to the little pop window and under the load from computer area it will show the file name...
click the upload button next to it.

The file name will then pop up below showing it has been uploaded...
you can only do one photo at a time and you can only load five per post.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Runs fine, goes no where(2001 4hp johnson)

Unless you just want to fix it for the fixin. I don't understand all the palaver.
I would think a used parts motor or a used shaft must be out there. I think I'd be savng it for parts and go out and find a better 3, 4,5,5.5 or 6 hp.
 

Ocean31@bellsouth.net

Seaman Apprentice
Joined
Jan 16, 2010
Messages
39
Re: Runs fine, goes no where(2001 4hp johnson)

I would have to agree to use it for parts, seems a lot of labor hours for very little savings.

I just bought a 1986 4hp Johnson for 50.00. The powerhead was locked up. I wanted the long shaft configuration that the engine had.

I do not know if the crank on the 86 would fit a 2001, but if wanted, I can send you the powerhead, (I just threw it into the trash) and you can just use that crank.

Might be better off trying to find a engine with a bad lower unit. THen trade out, you will make out in cost, and have a lot of good parts left over.

JSB
 

robert53a

Petty Officer 2nd Class
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Dec 27, 2007
Messages
181
Re: Runs fine, goes no where(2001 4hp johnson)

Thanks guys I've got my eye out for a parts motor of this. I appreciate the feed back.........Robert
 

robert53a

Petty Officer 2nd Class
Joined
Dec 27, 2007
Messages
181
Re: Runs fine, goes no where(2001 4hp johnson)

Hi I tried to post pictures, but to no avial. I bored the end of the crank out and inserted a 3/8 drive female in extention into where the internal spline used to be the drill the end of the crank and inserted a roll pin to hold in place. I loped off the drive shaft and drill the femail end of a short extention to a tollerance fit of the drive shaft and drill and drill and roll pin it too ( after a few test fit fot lenght) I reassymble the motor and cranked it up in the tank for a test. I t runs very smooth and has no noticable extra vibration(it is a two stroke). the test of time will be only way to find out for sure. I don't know if this is a common problem with these motors or not, but for the time being this one id fixed......Robert
 
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