Crankcase Taper Pin ?

gpsguru

Cadet
Joined
Aug 25, 2010
Messages
14
1997 Johnson 70 (3 cylinder) full remote.

I have the powerhead off now and will be pulling the crankcase apart to take out the seized / broken up piston (No3). There is a whole section in the workshop manual about being mighty careful when removing the taper pin that aligns the crankcase half?s. It details making a special tool to remove the pin. I am happy to make the tool but to not want to waste unnecessary time ???.normally for taper pins we would use a pin punch or just tap the two half?s apart using a block of wood. As I have never had a Johnson crankcase apart before what is the deal with the taper pin and how do you guys split the crankcase ?
 

oldcatamount

Lieutenant Commander
Joined
Apr 4, 2010
Messages
1,740
Re: Crankcase Taper Pin ?

After all the bolts are out, take a mallet and give the top section of the crank a smart tap. That will break the seal between the two sections. You may not have to mess with the taper pins at all.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: Crankcase Taper Pin ?

I've always tapped them out with a punch - never had an issue with them...
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Crankcase Taper Pin ?

I too have also tapped them out with a loooooong punch. Never did make the tool. Punch always worked fine.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Crankcase Taper Pin ?

We always used a punch too. Seen many front halves split at the pin because someone didn't take the pins out and tried to force the front off. Never bothered with the too either. I think the plans for the tool ended up in the junk pile with the rod alignment tool.....
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: Crankcase Taper Pin ?

A good sharp lead pencil is still as good as that rod alginment tool.
 

nymack66

Petty Officer 1st Class
Joined
Aug 5, 2009
Messages
356
Re: Crankcase Taper Pin ?

All good pointer for the FAQ section. Create a section on tips and tricks maybe a good idea? Thanks for posting the question and the follow up posts. I really enjoy reading some meat and potatoes in while :)
 
Top