1968 18hp johnson?

big ken · Feb 17, 2010

i have a guy that might want to trade me his 68 18 hp johnson for my 1966 9 1/2 hp johnson. ive heard nothing but good about my 9 1/2. what are the 18 hp like? thanks ken

jdsgrog · Feb 17, 2010

Re: 1968 18hp johnson?

I've got a '57 18hp johnson. Absolutely love the motor. Very solid and reliable. I know my motor is older and uses a pressure fuel tank, but if yours is in good running condition, these old johnsons are pretty solid...and easy to work on. BTW, I have motors all in the '50's and '60's vintage from 3hp to 33hp, and they're all great runners. Personally, I would take them over modern motors because they're so easy to repair and maintain by yourself and parts are readily available. If you can make your way around one motor, the others are pretty much the same.

steelespike · Feb 17, 2010

Re: 1968 18hp johnson?

I believe the 9.5 has some suspension components that are known to fail and are
difficult to find and a bear to replace. All the low profile motors are difficult to work on.The 18 is a wonderful motor reliable easy to work on reasonably light while
having a good amount of power.Capable of about 27 mph on a reasonably light fast boat,maybe more with some carefull tweaking and prop selection.We ran ours hard for 8 years only failures were directly related to poor maintenance.

1946Zephyr · Feb 17, 2010

Re: 1968 18hp johnson?

I also have a 57 18hp Evinrude and have had a few others in the past the same vintage. Great motors and actually easier to work on than your 9.5. I would do a compression test to make sure both cylinders are even as possible. On mine, I get 100psi on each cylinder and it runs great considering the condition of it, but if you get better compression than that, that is all the better.

So I would definately take him up on it.

big ken · Feb 17, 2010

Re: 1968 18hp johnson?

i think i will consider the trade. as far as a compression check, can i get a good reading using a pull start? what is the procedure for checking compression on a pull start? thanks ken

1946Zephyr · Feb 17, 2010

Re: 1968 18hp johnson?

remove both plugs
open the throttle all the way
crank the motor 5 times

That should give you the maximum compression reading.

Woodstock60 · Feb 17, 2010

Re: 1968 18hp johnson?

Although Zeph is absolutly correct, I find that an electric starter will give a higher compression reading on most motors.. besides the compression is not nearly as important as the balance, they say the lowest reading should be within 10% of the highest, I say it should be within 5%. That reading can be acheived by hand cranking.

KB1 · Feb 17, 2010

Re: 1968 18hp johnson?

'58 18 elec. start Johnny for me. Idled as well as my 10 and pushed my A modle Alumacraft very well. Go for it if you have a boat to handle it; get one that will!!!

big ken · Feb 17, 2010

Re: 1968 18hp johnson?

KB1 said:
'58 18 elec. start Johnny for me. Idled as well as my 10 and pushed my A modle Alumacraft very well. Go for it if you have a boat to handle it; get one that will!!!

i want to put it on as a kicker for my chinquatic 18 cc 88hp johnson. was going to use 9 1/2 just to push me around in the fresh water lake and crab in the chesepeake bay, but the 18 will be soo much better since 18 hp is the biggest hp they will allow in the lake. thanks for all the input guys ken ps will that be 50/1 fuel ratio also?

jdsgrog · Feb 17, 2010

Re: 1968 18hp johnson?

i believe the 60's motors were 50:1 ratio. the 50's motors were actually 24:1.

1946Zephyr · Feb 17, 2010

Re: 1968 18hp johnson?

yep, your 68 motor would be 50:1

cc67 · Feb 18, 2010

Re: 1968 18hp johnson?

I have several 18-20hp 50s and 60s motors. My 66 Johnson 20hp is my go to motor. Dead nuts reliable, never let me down.

Mark_VTfisherman · Mar 20, 2010

Re: 1968 18hp johnson?

quagmire60 said:
...I say it should be within 5%...

Hey- so what's been on the end of your fishing pole lately? Just spotted your post randomly surfing and thought I would drop a line. Of course that is a different thread topic I know

Watching the satellite photos to figure out when I can get on Champlain... Early spring this year.

should have been a pm :redface:

1968 18hp johnson?

Petty Officer 1st Class

Chief Petty Officer

Supreme Mariner

Vice Admiral

Petty Officer 1st Class

Vice Admiral

Petty Officer 1st Class

Seaman

Petty Officer 1st Class

Chief Petty Officer

Vice Admiral

Petty Officer 1st Class

Lieutenant