need to find year of johnson 20hp

[kawaboy-zx11]

i just bought an old 20 horse johnson, but the tag is missing on the boat mount. is there somewhere else i can look to find the model and serial #? i think i read its on the head somewhere but i dont see it. Thanks, Dennis

 

[Vic.S]

Re: need to find year of johnson 20hp

Sometimes the numbers can be found on a Welch plug on the power head

you are looking for one of THESE NUMBERS

 

[F_R]

Re: need to find year of johnson 20hp

Here

 

[kawaboy-zx11]

Re: need to find year of johnson 20hp

would you belive there is just a hole there? is there any where else to look? the shaft is REALLY dark brown almost black....if that means anything. i think its prolly from the 60's or 70's..... shoot, now im not even sure what hp it is but it was advertised as a 20hp. maybey if i post pictures we could all guess?? Dennis

 

[Daviet]

Re: need to find year of johnson 20hp

Yes, post pictures, lots of pictures. We like pictures.

 

[kawaboy-zx11]

Re: need to find year of johnson 20hp

pictures, pictures, pictures

 

[kawaboy-zx11]

Re: need to find year of johnson 20hp

2 more

 

[kawaboy-zx11]

Re: need to find year of johnson 20hp

one odd thing i noticed is the square silencer cover, none of my other motors ive had have had a square one....mabey thats year specific? Thanks, Dennis

 

[samo_ott]

Re: need to find year of johnson 20hp

My '66 J20 that I was working on today has the exact same square silencer and looks very similar but your engine looks a bit more modern. So my guess is '67-'70. Go to this site and compare pictures:

http://www.old-omc.de/

Are you sure there's no plate on the transom mount?

 

[restornator]

Re: need to find year of johnson 20hp

Just judging by the cowl i'd say 1968. YOu are definitely looking at a 1968-70 when Johnson used that dark forest green paint. There were a lot of changes between 67 and 68

 

[kawaboy-zx11]

Re: need to find year of johnson 20hp

some observations i have made indicate that it is a 1969 or 1970 (assuming the cowl is the original one). i gathered this by.......the ones before 69 had the "soap dish" tray for the pull the handle and in 71 they no longer had the plastic rectangle emblem on the rear of the cowl. yes i am positive the tag is missing as i can see the holes where it used to be. yesterday when i bought it, it only had spark on one cylinder so i cleaned and regapped the points and now there is lightning like spark on both cylinders, i was delighted to see that it looks like someone recently replaced both coils,points and condensers. the only problem i have now is i have to figure out why the linkage to the carb won't open the carb when i turn the handle, it advances the ignition just fine but i have to open the carb by hand, i guess the linkage is worn out that opens the carb. Thanks, Dennis

 

[Vic.S]

Re: need to find year of johnson 20hp

the only problem i have now is i have to figure out why the linkage to the carb wont open the throttle when i turn the handle, it advances the ignition just fine i have to open the carb by hand, i guess the linkage is worn out that opens the carb.

As you open the throttle and the armature plate turns the cam bolted to it, #42 in THIS DIAGRAM

should operate the throttle on the carb via the cam follower roller #53, and link #55 see THIS DIAGRAM

Check that your roller is not missing

 

[kawaboy-zx11]

Re: need to find year of johnson 20hp

ahh yes, thank you for the link to the parts diagram, thats exactly what i need to look at when i troubleshoot the problem, i am pretty sure i am missing the roller. once i find out whats missing or worn i think this motor will be good to go. i think this is going to be a really good motor, i couldnt pass on the good deal i saw it for. i found it for on craigslist, and i assumed i would have to replace the coils, points, condensers and put a carb kit in it but it appears all that was done recently. the guy i bought it from really knew nothing about it. he said he aquired a whole truck load of outboards and this was one of them. Thanks again, Dennis