Just had a bit of a narrow escape this morning.
The old plugs in the motor looked a bit sad from corrosion on the outside (no idea when they were fitted) so I thought while I have the boat out of the water, try and coax them out (they looked like they might take some shifting so I didn't bother doing it while the boat was in the water in case one broke off) and see what they looked like. It has misfired a bit at idle since I got it but runs fine at over 2000rpm so I wasn't too concerned.
I should have been....
They came out easy enough (though I did soak them in WD40 yesterday as a precaution) but...
New plugs are set to 30 thou gap according to the book....
These were all between 50 and 55 thou!
and what is more when I was wiggling the humungous stack of feeler gauge fingers in to find this out, a bit of a twist and on 3 of the 4 the end electrode broke off! (very brittle - just snapped with no effort at all)
Today cost me £6.80 for four new NGK's, it could have been so much more if I had an electrode rattling round in the cylinder .... lesson for the day must be that prevention is better than cure and if there is any doubt about whether something has been done in the way of maintenance, assume that it hasn't!