Re: 77 Evinrude 35hp Blowing Plugs
I have no idea what a "rode" is. However, if you're speaking of the center spark plug electrode, are you speaking of the center portion that extends from the porcelain or the elbow portion leading to ground? You also say the same cylinder but do not say which cylinder... it does make a difference.<br /><br />In any case.... what is the compression readings of the cylinders, and does the spark (with the spark plugs removed) jump a 7/16" gap with a strong blue lightning like flame (a real SNAP!)?<br /><br />What spark plugs are you using, and at what gap setting?<br /><br />Normally the problem you speak of is caused by a slight amount of water somehow entering the cylinder or the spark is too far advanced. Note that the improper spark advance setting would usually affect all cylinders.<br /><br />A lower compression reading on that cylinder would lead one into a failing head gasket or wearing sealing surface of the cylinder head or the block area.... but keep in mind that water can and will enter via other areas such as the exhaust baffle plate (either cylinder) or the powerhead seating gasket area (usually the bottom cylinder) to name two.
