new to me 1970 ish Johnson 20 hp

[fishermanof93]

I got a 20 hp johnson outboard the other day that had been sitting in a garage for a couple years. I have already cleaned/rebuilt the carb and water pump. The compression was 126 in both cylinders and their was spark but it just didn't seem very strong had a gap tester and it was jumping the 5/16 gap i have read about. I took it out on the water today and had a terrible time getting it started I did get it started with a shot of starting fluid which i know is a nono but i did it. It did run fairly well once started. anyways i was wandering what you guys thought about the starting thing also i am missing a piece on the carb that controls the tuning needle. Attached is a picture of the motor and the front of the carb some sort of a cam shaped nut goes on the end of that brass piece i believe if you know what that is and where i can find one that would be really helpful along with a possible year and any thoughts on the stating issue

 

[F_R]

Your choke spring is missing or broken or something, and somebody rigged a piece of wire in there. I think the spring is part number 315241. The plastic arm that snaps on the end of the idle mixture needle is part number 204705. Try your friendly local Evinrude dealer. Or go to the BRP (Evinrude) website.

 

[fishermanof93]

Thank you F_R will order those parts any idea what year this motor is or which model it is? Do you know how to set that idle mixture needle. i was also wandering if there was any thoughts on rebuilding the ignition system?

 

[pckeen]

Doesn't sound like an ignition problem - sounds like a choke problem. If it runs well after you get it started, this is a sign that the mixture isn't rich enough at start up - choke problem. Fix that first before you think about rebuilding the ignitiion system.

 

[hardwater fisherman]

Look on the round circle freeze plug just behind the fuel pump. It may indicate what year it is.

 

[fishermanof93]

thanks for the info everyone.
Pckeen,
could a week spark not cause it to be hard to start and still run after? the choke system all appears to be working is the reason I ask. where would u start on working on the choke keeping in mind I just cleaned the carburetor and made sure all the passages are open.

 

[pckeen]

You may be right - but when diagnosing an engine - start with the obvious problems - the jury rigged & missing parts on the choke. No point spending the money on replacement parts for the ignition system until you have clearly ruled that out.

 

[gm280]

Can't say for certain but that color was on my 1976 40HP Johnson engine. I could tell more by seeing the cowling... But that little freeze-plug looking disk on the top of the engine will decode the year like previously stated...

 

[fishermanof93]

thanks again everyone for your quik feedback I will get the numbers off that freeze plug tonight and see what I can gather there got the new spring and plastic cam piece ordered for the carb an choke so will see may go ahead and tear into the ignition area just to see what I see until those pats come in. thanks again everyone.

 

[fishermanof93]

the freeze plug says J2770618

is this the model number or what?

 

[bonz_d]

On BRP website it looks as if 1973 was the last year of production for the 20hp and those numbers you posted to not coincide with any of the models listed back to 1968 which is as far back as they go on their website. Is there not a model tag attached to the transom bracket on the left side looking from the spark plug side?

 

[F_R]

The number on the freeze plug is the serial number.
EDIT: I figure it is a 1967
EDIT, EDIT: Now that I know that, I gave you the wrong number for the choke spring. Should be 303316 for 1967

 

[fishermanof93]

the only other number on the actual motor that i can find is on the left side and it is 381741

 

[fishermanof93]

thank you guys again for all your help i really apriciate it. the only other question i got is if anyone has any idea how to set the tunning needle.

 

[bonz_d]

Right above where the engine is sitting on the transom is a tag. Right below where you see the gas hose. That tag will have the model and serial number on it. As in this picture.

 

[F_R]

thank you guys again for all your help i really apriciate it. the only other question i got is if anyone has any idea how to set the tunning needle.

If somebody has already monkeyed with it, screw the needle all the way in (GENTLY). Then back it out 1-1/2 turns. Start motor and let it run to warm up....preferably on a boat on the lake. Now, at slow idle speed, slowly turn the needle in till it falters or stalls. Then back it out again till it regains smooth running. If you are doing this in a tank, do it with the hood off. But you will have to fine tune it again when you get out on the real water. Note, it is an idle mixture control, and has virtually no effect on speeds above idle.

 

[fishermanof93]

Right above where the engine is sitting on the transom is a tag. Right below where you see the gas hose. That tag will have the model and serial number on it. As in this picture.

There isn't a tag there it's been removed and/or painted over.
F_R thanks u for the info I will get those things fixed and let u guys know how it turns out

 

[racerone]

Based on colour of the paint I would say 1967.------Does not really matter what year as parts were essentially the same year after year.

 

[fishermanof93]

got the new parts in and installed wet ahead and rebuilt the magneto since I was waiting anyways which turned out good taking it to the water tomorrow to see how she runs. on the tuning needle I got it set like you said from home and will fine tune it once on the water but my question is when starting the boat more for future reference is it better to have that nob turned in or out from the outside adjustment.

 

[tomhath]

Make sure you have the throttle opened up when you're starting it. With it in neutral it won't open all the way, but open it up that far. The "Start" mark on the tiller handle is often nowhere close. Two stroke motors almost always want the choke closed and throttle open to cold start, and both open to start when hot.