1972 Johnson 9 1/2

billy4hp

Petty Officer 1st Class
Joined
Jan 31, 2009
Messages
245
Hello all, great site, what a wealth of knowledge around here... So I am looking to tap into a little bit...

I recently acquired a 1972 Johnson 9 1/2 that I plan on using as a kicker / emergency spare on my also recently acquired 16ft Glasply (Pacific NW boat for those not familiar)... Anyways is this OB a reliable kicker for all day trolling, etc?

It has been kind of a mess, previous owner bought it off Craigslist and that previous owner did some work or had some work done that wasn't up to snuff. Tiller handle was stuck due to the carb linkage being jammed, thermostat housing was leaking, etc.

I got it running on a saw horse w/ hose and the water stream is good, engine runs decent but will "sneeze" every once in awhile, almost seems like a lean condition as it's not just a consistent "bump" like it's a ignition miss.

Really have not run it that long, it's a bit cold up here (40 deg F) and I know some two strokes doen't really enjoy the cold weather so I don't know if that has anything to do with it...

Haven't done a compression test yet but the spark plugs look reasonable for the little bit of time I have run it...

Since I have everything all buttoned up I am going to really give it a run tomorrow up to operating temp and see if it smooths out with a bit of heat in it...

Thanks for any and all advice,

Billy
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 1972 Johnson 9 1/2

I would replace the impeller, don't burn up a potentially good motor, rebuild the carb, and carb adjustments. read this. http://forums.iboats.com/showthread.php?t=158086 and this http://forums.iboats.com/showthread.php?t=167352

also if trolling set your plug gap at .035 first, if they carbon up, go to .040. this is for low speed running.

you can also decarb the motor to get the old crud out, which may help idle.

Decarb, take a can of seafoam put 3/4 of it in the gas tank, with only 1 gallon of premixed gas. put the rest in a spray bottle. start the engine, and let it come up to temperature. then remove plugs, and them some real good shot of seafoam into the cylinders, replace plugs, let sit 15 minutes. restart, and spray the rest of the seafoam into the carbs, so the the motor almost stalls, wait and repeat until the seafoam is gone.then take for a wide open spin. then put in new plugs, ad premixed gas to the tank, and take it for a wide open throttle spin. it is going to smoke like a house on fire, during this process.

afterwards compression.recheck
 

billy4hp

Petty Officer 1st Class
Joined
Jan 31, 2009
Messages
245
Re: 1972 Johnson 9 1/2

Thanks for the quick reply and the advice, I'll gather up the parts and post up the results....

Billy
 
Top