1977 70 HP Johnson Outboard engine question

[mac103342]

hello, i need some help. I have a 77 johnson 70 hp 3cyl and i had a bad oil mixture earlier this year. This caused oil to come out the exhaust and i replaced the spark plugs because they were full of oil deposits. and it was working fine now it is bogging down when i accelerate. it starts fine and warms up fine but when i put the warm up lever down or accelerate it dies or at least wants to. anyway i checked the plugs again and they have oil deposits again. i looked inside the spark plug holes and they are full of oil. is there supposed to be oil there? and what can i do to fix this? thanks for any help.

 

[mjash]

Re: 1977 70 HP Johnson Outboard engine question

#1 what was the mixture ratio?<br /><br />#2 do you have spark to all cylinders.<br /><br />If one or more cylinders arent firing, you will get oil from the exhaust.

 

[mac103342]

Re: 1977 70 HP Johnson Outboard engine question

Hello, my mixture is 50:1<br /><br />I had spark to all 3 cyllinders, but then it started to bog down and dies when accelerting. The motor turns over and starts perfectly and i pulled out the spark plugs and they were full of a black substance. smelled of gas.

 

[mjash]

Re: 1977 70 HP Johnson Outboard engine question

Sounds to me that your plugs are loading up. You need to see if you are getting spark when this condition starts to occur. Pull one wire at a time(with insulated pliers)and see if there is a change in RPM. At this point it could be a number of things. Is your timing advancing. Are carbs functioning properly. Got to get it narrowed down.

 

[mac103342]

Re: 1977 70 HP Johnson Outboard engine question

when this substance is on the plugs i will lose power to the #1 spark plug. also i know that when i replaced the spark plugs today it ran fine but there was alot of grey smoke, however the mixture i was told to use is 50:1 and that is what i use.<br /><br />the substance seems to be the worst on plug 1 and less on the plug 2 and plug 3 has little substance on it at all.

 

[mjash]

Re: 1977 70 HP Johnson Outboard engine question

Sounds like you have weak spark on 1 amd maybe 2.

 

[mac103342]

Re: 1977 70 HP Johnson Outboard engine question

how can i fix this? replace the coil pack(s)?

 

[mjash]

Re: 1977 70 HP Johnson Outboard engine question

You need to troubleshoot further. If not, you will be throwing alot of expensive parts at this. If you do a spark check with plugs clean, will all cylinders throw a spark 7/16"?

 

[BoatBuoy]

Re: 1977 70 HP Johnson Outboard engine question

What plugs are you using?