Johnson 4.5 HP 1982 sparkplugs high idle

[Knutos]

I have model J5RHCIC Serial B005941 can anyone please tell me what sparkplugs i need?<br />Its idling too fast and is also fouling . When i run it in a tank the water gets full of black oil, and the shaft is quite greasy after som testrunning this weekend. Is this normal? i mix in 2 % oil and use normal 98 octan gas

 

[jcockrell]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

not sure about the type of plug,but a new set and 50-1 or 16oz of oil to 6 gallons of gas should help the problem. GOOD LUCK

 

[Knutos]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

Well, 50-1 is 2 % isn't it?

 

[bubbakat]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

1981<br /> plug champion QL86C gap at 30<br />fuel mix 50:1

 

[rickdb1boat]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

Bubba has it(CI) is 1981 Model. And 2% is correct. And running it in a tank and seeing the unburned deposits is normal. That's something you would not notice in the lake...

 

[rickdb1boat]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

 

[Knutos]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

I have L7JC4...<br />gap 30 is that inches? 1 inch is 2,54 cm and 0.030 is close to 0.7 mm which is what i have today.<br /><br />Is there any possibility to get more power than 4.5 HP?

 

[Knutos]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

yes I know it's 1981, but is Bubba right when he says the right plug is champion QL86C gap at 30?

 

[rickdb1boat]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

L77JC4 will work. No way to gain performance, unless you are under or overpropped now. Go a little wider on the gap. .040 will reduce fouling at lower speeds and may give you overall better running at all speeds.<br /><br />And yes, he is correct on the plug. It's a hotter burning plug than the L77JC4.<br /><br /> Spark Plug Chart

 

[Knutos]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

Thank you, this have been very halpful to me. I will change sparkplugs tomorrow, increase gap to 40 and go fishing

 

[Knutos]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

New sparkplugs but no difference, plugs are wet and dirty after a few minutes, and stops when i turn power to slow speed

 

[Chinewalker]

Re: Johnson 4.5 HP 1982 sparkplugs high idle

Hi Knutos,<br /> Sounds like you have other issues to deal with. How is the compression on your motor? Compression should be at least 70 psi in each hole and within 5% variance between them. Low compression could give you the problems you're having...<br />- Scott