Your colder plug and presumably I cylinder to me indicates that it has an intermittent misfire. Check the ignition and plug in that cylinder if they are ok. Then check tappet clearances.
Also do a wet and dry compression test to check out valves and bore. I had this when a tappet came loose thus keeping a valve constantly closed.
John Mason.
Also do a wet and dry compression test to check out valves and bore. I had this when a tappet came loose thus keeping a valve constantly closed.
John Mason.
Would you believe it "Her who must be obeyed" refers to my Ruby as the toy.