spark plugs 74 9.9 evin

[mav1973]

i have a 1974 9.9 evinrude just wanted to see if there is a better plug than champions they keep fouling just got tune up useing ul81c now thanks for the help o gas miw 50.1 oil is evinrude brand

 

[bubbakat]

Re: spark plugs 74 9.9 evin

the plug should be a UL81C gape at 30 <br />this is the plug the maker advise to use

 

[OBJ]

Re: spark plugs 74 9.9 evin

Hi Mav....<br /><br />Just a few things to consider about fouled plugs.<br /><br />Compression good? 90psi or better per cylinder is always nice.<br /><br />Is the engine temp where it should be? Not running cold. At idle, you should be able to put your finger on the flat area ontop and just behind the head for several seconds before having to move them.<br /><br />Will your spark jump a 7/16 gap with a hot blue spark?<br /><br />When was the last time the carb was rebuilt? Float setting correct?<br /><br />Fuel line connections tight.<br /><br />Just a few things there to think about.