Bottom plug keeps fouling Johnson 70hp

[John Dudley]

I have a 1999 Johnson 70hp model BJ70PLEEE that keeps fouling the bottom plug of the three. Looks like fairly light ash build up. I have put new plugs in but the bottom one is building up deposits very rapidly. When I bought the motor it had had the oil mix mechanism removed and I am using 50:1 mix.<br />The engine goes like a shower, but seems to misfire a little at low revs.<br />Any thoughts?<br />Thanks

 

[rickdb1boat]

Re: Bottom plug keeps fouling Johnson 70hp

John,<br />What # plug are you using? Are they gapped at .030? Do you do a lot of slow trolling?