1999 Johnson 25 HP 3 CYL- Correct spark plug

[oldnorthguy]

Subject motor came with the oil injection system disconnected by the dealer. <br />Manual calls for a Champion QL86C plug. Motor came with QL82C.<br />Plug listing thru Google suggests QL82C to be correct.<br />What is the difference between the 2 plugs. Dealer states either is fine.

 

[ob]

Re: 1999 Johnson 25 HP 3 CYL- Correct spark plug

The Champion QL82C is the only one I see listed for your engine.Gap is .030".

 

[oldnorthguy]

Re: 1999 Johnson 25 HP 3 CYL- Correct spark plug

Thanks guys. Investigation suggests that the QL86c is a hotter plug.<br />I am still puzzled by the fact that the Johnson's maintenace manual calls for QL86c<br />rather than the QL82c plug that came with it. and which all the sparkplug charts I've been able to find indicate to be correct. I guess until I resolve the issue I'll stay with <br />what it shipped with, although there is some fouling showing possibly due to the richer mix during the breakin period.

 

[seahorse5]

Re: 1999 Johnson 25 HP 3 CYL- Correct spark plug

The official OMC Parts and Accessory Guide calls for the QL86C plug to cut down on some of the fouling problems the early models had.