'72 Johnson 50hp smoking at start up

[michael37659]

Howdy everone
I recently bought a boat that came with a '72 Johnson 50hp #ESL5072c.At start up i get excessive smoke and then it goes right away.It was smokin when i got itso i checked my compression and both cyl. was 125 each.Then i took the carbs off and soaked them ran some strands of wire through passage ways and blew them out with air comp. and then rebuilt them.I adjusted the float level with the little measuring gauge that came with the kit.Then i decarbed the engine 3 times taking it to the lake inbetween cleanings.Im usuing a quality oil mix-penzoil.The ole johnson is running great from idle to wop, but im getting the excessive smoke just for a min when i start it then it goes away.The plugs are new that came in the motor and are a autolite 2892.Im starting to get stumped on the problem.Id appeciate it if someone could help me out with some suggestions.I ordered a manual for the motor and havent got it yet.Thanks.......

 

[F_R]

Re: '72 Johnson 50hp smoking at start up

My best guess is that there is nothing wrong with it and it doesn't need fixing. The extra fuel required for starting is what makes it smoke. That extra fuel comes from the choke. Long story short---it is acting normaly.

OK, the rest of the story: That motor has an automatic warm-up choke that holds the choke plates partially closed during the warm-up period. That will increase the smoke too. Try pushing the manual choke knob all the way in (choke-off position) and see if that helps.

There is a service bulletin that tells how to re-wire the choke to disable the warm-up phase. Check back if you want that info.

 

[michael37659]

Re: '72 Johnson 50hp smoking at start up

Thanks FR
I push tha manual choke knob in and that did wonders.It didnt smoke hardly any after that.I would appeciate the info on how to re wire the choke.Once again .........Thank You

 

[kenmyfam]

Re: '72 Johnson 50hp smoking at start up

As said, nothing actually wrong with it by the sounds of it. My 140hp does exactly the same thing and always has. I get a kind of warm and fuzzy feeling knowing it's getting enough lubrication from cold start up.

 

[mars bar]

Re: '72 Johnson 50hp smoking at start up

I have the exact motor and mine smokes at start.

 

[michael37659]

Re: '72 Johnson 50hp smoking at start up

Thanks fellows, that makes me feel awhole lot better,i just wasnt sure if it was normal or if something was goin on that might give me a problem down the road or lake i should say.
once again thanks....