1972 Johnson 50hp 50ESL72C Questions

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

fstorm: Hey man, I have the same motor and went through the same thing last season changing the impeller. Believe it or not, I also broke one of those bolts on the water pump too, my bolt actually broke off screwed into the hole. So I have one less bolt for the water pump. I tightened the remaining ones down and then sealed it of with the blue gasket seal stuff. I don't have a tell tale but the water comes out the exhaust ports like it is supposed to do.
No cup, mine looks just like yours.
I don't remember a seal being between the pump and water tube, but I will check my manual and get back to you on that.
Not sure about the exhaust seal, mine probably needed to be changed but I decided to put it off till next season.
I had a lot of unburnt oil/gas mixture coating everything inside mine but that was before I rebuilt carbs and put in new plugs and fuel lines.

Thanks for the response Hoyt sounds exactly the same
Have you decided on the tell-tale on yours?
The impeller plate is in pretty good shape on mine but will replace it as I believe one comes with the waterpump kit.

 

[Hoyt79]

Re: 1972 Johnson 50hp 50ESL72C Questions

Still mulling it over in my mind...I will probably get the guts up to do it at some point. Been running my motor on the water several times and everything runs fine...enjoying the heck out of this motor!

 

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

Hi Everyone,

Well I finally have some time to get back on the motor/boat so I am looking to replace the leaking power-head gasket (the one between the crankcase and exhaust housing.

I believe I have all the bolts removed but just cannot seem to separate these. :embarassed:

Has anyone ever done this and can provide any insight?

Is it possible that these are corroded together?

Thanks in advance for any info you can provide

 

[bonz_d]

Re: 1972 Johnson 50hp 50ESL72C Questions

I just recently picked up a 1975 50hp and was concerned when I saw this same thing. I latter learned that this is normal and is part of the way the water flows through to cool the exhaust housing. If you look there is also a drain weep hole in the front side between the lower unit and the mid-section exhaust housing and there should be water squirting out of that hole while it's running..

 

[jbjennings]

Re: 1972 Johnson 50hp 50ESL72C Questions

Hi Everyone,

Well I finally have some time to get back on the motor/boat so I am looking to replace the leaking power-head gasket (the one between the crankcase and exhaust housing.

I believe I have all the bolts removed but just cannot seem to separate these. :embarassed:

Has anyone ever done this and can provide any insight?

Is it possible that these are corroded together?

Thanks in advance for any info you can provide

I think the consensus was that the powerhead gasket was probably not the problem. If F_R and JayMerrill don't think that was it, I would not worry about it. F_R was a professional outboard technician for many years and has worked on lots of these, I'm sure. I own one and rebuilt it and it's still running great. I would hate to see you pull the powerhead for no reason.
JBJ

 

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

Thanks for the responses bonz_d and JBJ.

 

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

She's going to need some tweaking but she's pushing water good.

[URL=http://i767.photobucket.com/albums/xx320/fstorm08/20130414_154040_x2641_zps49ec699c.mp4] [/URL] :joyous:

 

[bonz_d]

Re: 1972 Johnson 50hp 50ESL72C Questions

Way to go!

I myself just picked up a 1983 60hp Johnson 2 cylinder. Runs great but looks as though it's going to need a waterpump.

 

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

Can anyone help in how to hook up a tach for this motor?

Got he motor sprayed with zinc chromate primer:



I was able to get her painted too:



Thanks in advance for any assistance

 

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

Can anyone recommend some soundproofing for inside the engine cowl?

The old foam was junk.

Thanks in advance!

 

[tallcanadian]

Re: 1972 Johnson 50hp 50ESL72C Questions

Motor looks great. Nice job on the paint. It runs very smooth too, smooth as silk.. These two cylinder Johnsons, I hear and very good on fuel too.

 

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

Motor looks great. Nice job on the paint. It runs very smooth too, smooth as silk.. These two cylinder Johnsons, I hear and very good on fuel too.

I am hoping she is efficient and dependable

 

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

Starting to think about the tach connection to this motor.

From what I can see, I will need to run a sending wire from the tach to a specified location on the motor.

Also, that's the best spot to hook into the ignition power for the tach as well?

The tach is a Teleflex Eclipse:

TACHOMETER 0-7000 RPM, 3 Inch : Amazon.com : Sports & Outdoors

Thanks in advance everyone.

 

[fstorm08]

Re: 1972 Johnson 50hp 50ESL72C Questions

Starting to think about the tach connection to this motor.

From what I can see, I will need to run a sending wire from the tach to a specified location on the motor.

Also, that's the best spot to hook into the ignition power for the tach as well?

The tach is a Teleflex Eclipse:

TACHOMETER 0-7000 RPM, 3 Inch : Amazon.com : Sports & Outdoors

Thanks in advance everyone.

I figured it out.

The tach sending will connect to number 2 (yellow w/grey strip) terminal block and the ignition source I can get from connecting the number 3 (red) terminal on the block.

 

[fstorm08]

Hi Guys,

I am currently running a 13.5x15 prop and getting about 3600-3800 wot on my 14 ft Glassmaster with this motor.
I currently have a second prop 12.5x13 that I am going to try after I do a compression check on the cylinders.
So I guess my q is, what generally should I expect with propping down 1" in diameter and 2 sizes in pitch? I know that with each drop in pitch size, you generally gain ( I think) about 200rpm.

Thanks in advance!
Ryan

 

[fstorm08]

I have the results of the compression test I did.

Top and bottom cylinder held for a 15 second count time before I released the pressure.
I did this 4 times on each cylinder and came back with:
Top: 170
Bottom: 140
The 170 seems high but need to do some research on what the compression typically is on this motor.

Anyone have any take if this seems a bit off between the two cylinders or what the should be at?

Thanks in advance,
Ryan

 

[ronward]

Might wanna try a different gauge. Your numbers are way off and 170 is way high anyway. My '73 50 had 145 on both (verified with a 2nd gauge), it was a very lightly used motor, a normal use motor should show 130-140. Even a little lower it will still run good just may be a little down on power. Are you sure you have the tach set right? Mine ran 5400 with a 13 1/4x17 on a 14' glass tri-hull

 

[fstorm08]

Might wanna try a different gauge. Your numbers are way off and 170 is way high anyway. My '73 50 had 145 on both (verified with a 2nd gauge), it was a very lightly used motor, a normal use motor should show 130-140. Even a little lower it will still run good just may be a little down on power. Are you sure you have the tach set right? Mine ran 5400 with a 13 1/4x17 on a 14' glass tri-hull

Thanks ronward. I'll grab another gauge and see what I get then.

 

[fstorm08]

Here's a question on the tach setup. Is this motor setup on the tach side as a 6 pole?

 

[fstorm08]

Here's a question on the tach setup. Is this motor setup on the tach side as a 6 pole?

I found some info on other sites that say to set the tack to 5p so I will give that a try and report back