1975 2cyl Johnson 25hp outboard idles super fast at startup!!

Joined
Jul 7, 2011
Messages
11
Sorry if this has been asked before? I have a 1975 Johnson 2cyl 25HP tiller style outboard that was running great. Memorial Day morning, got it in the water and when I pulled to start it, it idled really fast. Really Super fast! When I pulled the choke out a bit, it would slow down. When I pull choke all the way out, it will kill the engine. I noticed that the throttle handle doesn't want to spin as freely either? Any remedy would be appreciated? What is causing this? How can I fix? I have a link of the actual motor running on YouTube http://youtu.be/HoV39W30oC8
 

bullcity101

Seaman
Joined
Mar 30, 2012
Messages
73
Re: 1975 2cyl Johnson 25hp outboard idles super fast at startup!!

What you are doing by pulling the choke is cutting the amount of air that can get to the carb, hence it slows down. I would check your linkage to your carberater. Sounds like you have a kink or something that will not let the carb get down to its idle posistion. When it is running, try to take the move the linkage on the carb by hand to get it down. If it slows down, you know its a linkage problem. You could also take off the linkage to your tiller to make sure it is seating all the way down.
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
Re: 1975 2cyl Johnson 25hp outboard idles super fast at startup!!

On some older Johson motors the gear at the back section of the tiller arm will get missmatched from the tiller arm being moved up and will jump cogs and could cause your troubles. You can see the gears( cogs) buy lifting the tiller arm and they will be at the joint.
Oldman570
 
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