Help with 1978 55hp Johnson- loads up at idle

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Skidooosl

Petty Officer 3rd Class
Joined
Mar 5, 2002
Messages
94
I have a 1978 55hp Johnson that came on a boat I just purchased. For some reason the motor seems to load up and bog or stall often while at idle or low rpms. I changed the spark plugs which were very worn ( the metal piece that sticks out from the side under the electrode was noticeably warn down) and I noticed on the coils that the plastic part where the plug wire comes from which is attached to the metal bar that bolts to the engine seems to be loose and can wiggle some where the top cylinders coil seems to be tight. Is that bad? As long as you keep it above a idle the outboard seems to run good.<br /><br />Right now I am thinking rebuild both carbs and one new coil…. Anything else I should look into?<br /><br /><br />btw, it is a 2 cyl not 3
 
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Skidooosl

Petty Officer 3rd Class
Joined
Mar 5, 2002
Messages
94
Re: Help with 1978 55hp Johnson- loads up at idle

I am going to drive up and see if i can get the kits right now. does this outboard use points or anything else that may need to be replaced? Right now my plans to get this outboard back on the water are<br /><br />1 new coil to replace the loose coil<br />2 carb rebuild kits<br />1 water pump<br /><br />Anything else I should check or replace on this outboard? I will be using it on the Detroit river and Lake Huron and Erie so it is important that it is running GOOD<br /><br />Where is a good place to get the stuff to decarb? which of the products seems to work the best?
 
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Skidooosl

Petty Officer 3rd Class
Joined
Mar 5, 2002
Messages
94
Re: Help with 1978 55hp Johnson- loads up at idle

I rebuilt both the carbs and it still bogs down and stalls at idle speeds.... what next?
 
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hooksetter62

Seaman Apprentice
Joined
May 16, 2005
Messages
40
Re: Help with 1978 55hp Johnson- loads up at idle

decarb your engine using sea foam,works great. can eliminate alot of other problems also. use i gal gas,3-4 oz sea foam and 3 oz of oil,run at diff rpms then let idle until its all used up, let it sit for about an hour,restart with reg fuel supply and run for awhile. then reset idles to proper rpms. get to the water and drive it to clear it out. should help alot,made a big diff in mine. good luck
 
Pony

Pony

Rear Admiral
Joined
Jun 27, 2004
Messages
4,355
Re: Help with 1978 55hp Johnson- loads up at idle

Well hopefully someone can jump in and help you with the bogging down issue, but as far as decarb products go, Seafoam is by far the best product I have used. It really is incredible stuff. Most auto parts stores around here where i live carry it. If its available to you I would use that, and I think most people in this forum could probobly attest to that.
 
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