I wonder if anyone can assist with working out why one of my spark plugs appears to be ďrustingĒ rather quickly.
Its the bottom plug in this photo. Both plugs were brand new at the start of the season and although I go long multi day trips with the OB , I doubt they have done 1500 miles so far. I check everything out after every trip and canít say I noticed the plug colour last time. I do unscew them and check the electrode colours after every trip too and both are still a nice tan brown with no soot as expected.
Is it because I perhaps didnít tighten the plug enough? It certainly wasnít loose when I unscrewed it but I donít overtighten them when I put them in ..possibly finger tight then a half spanner turn after that, as I seem to recall the washers should not be compressed with over tightening ?
Is it a sgn of something more sinister ..or just a ďFriday afternoonĒ plug ? I have swapped them over for the next trip to see what happens and I always carry a spare set anyhoo.
The engine runs faultlessly and starts easily ..so I donít think its a problem.
Any ideas why the plug is different ? Its never happened before
A closer view of the offending plug
How tight do you screw up your plugs ? I donít own a torque wrench so hopefully a verbal description will help me. Thanks for any thoughts on the matter.