Hard to start HA 10 Johnson (1940) 2.5hp

[Monte NZ]

Hi All
As a change from restoring my 1964 3hp, I thought I would have another look at my HA which has been sitting untouched for many years.
Years back I managed to get it to start briefly, but eventually gave up and put it in the “too hard basket”.
There was spark on both cylinders, but the compression guage was only showing 55 psi on the top cylinder and 60psi on the bottom which I would think is possibly part of the problem.
I suspect too that the plunger seals would also be part of the trouble, going on what I have read on our website.
The motor is complete and appears to have only been used in fresh water……..attached are three shots of the motor

https://photos.app.goo.gl/yQF6TXi3tGcBrUJe7
Needless to say, I would appreciate your thoughts and comments

Thanks in advance
Monte NZ

[Buccaneer]

I just looked at the notes on my HA-10, that I went through a few years ago.
It had 66 & 68 psi compression. I have video proof that it run, but it
would not idle down without dying. I’m not sure if I was able to rope start it,
or if I used a drill.

It seems that the smaller the bore engine you have, the higher compression
you need. I’m not sure what these engines had for compression new, but
guessing at least 75 psi.

Not sure what the “plunger seals” are that you refer to?

Prepare to be boarded!

[crosbyman]

H types seem to have the same primer (plunger) as TN’s …. needs leather seals

see Johnson manual on H series

Joining AOMCI has priviledges 🙂

[Tubs]

https://youtu.be/O9lqeUHLcis

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

[lloyd]

Your HA10 needs 70-75psi to start and idle well. Most of these motors still have adequate compression because they ran on 16:1 oil mix and the leather primer seals wore out long before the rings or cylinders wore out. So it’s possible that your compression may come up to adequate with some penetrating oil to free up the rings. In any case you will need new leather primer seals and instructions to install them. Look below for the TN26 discussion for info about the primer seals

[crosbyman]

http://www.pochefamily.org/outboard/CarbService.html

Joining AOMCI has priviledges 🙂

[Monte NZ]

Thanks very much everyone for your replies!
Your experience Bucaneer re your HA ties up perfectly with mine, with the only difference being that your compression was much higher than mine. The plunger seals are the ones in the Primer that crosbyman mentioned which are also used in the TNs. and thanks crosbyman for drawing my attention to the excellent pochefamiy site……very informative!
Thanks Tubs for the video and the excellent photos……your LS-37 runs beautifully. Your comments about the rings make sense, but I am sure surprised too at the ring gap at the bottom of the cylinder.
Thanks Lloyd for your input too. Your new primer seals would be a must have going on the age of the motor. My problem there, is that getting anything by mail from your end
hopeless now, as currently there is no mail to NZ……..I mentioned recently that I am still waiting for my July issue of the Outboarder!
One point I forgot to mention, is that after that short run, I put a dose of Sea Foam through it as per the instructiions and going on what I had read on our website., but it didn’t help.
From all your comments, I think fitting new rings would be most important first step, which brings me to the next question, does anyone know what size rings are needed?
Fortunately there is a ring manufacturer about 45min drive from my home.
‘
Thanks once again for all your help.
Monte NZ

[crosbyman]

primer seals….. maybe you can try 2 ….proper sized O rings as a test

glad the Poche site was helpfull

Joining AOMCI has priviledges 🙂

[Tubs]

Tubs

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 3 years, 6 months ago by Tubs.

[lloyd]

Take my word for it! O-rings will NOT work to replace the original leather primer seals.
I have sent primer seals and installation instructions to NZ, Australia, Canada, and Europe in the past. But it is up to you to provide US currency and proper postage along with your Self Addressed Stamped Envelope.

[Author]

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