Spark plug time.
Thought I’d go along the iridium route, they last longer and the gap shouldn’t go out of spec for a long time.
Looking at Gutsibits, it’s a NGK BPR7EIX, seen it elsewhere as BPR6EIX, the EIX suffix denotes iridium.
I’ve gone through this before when I changed the plugs… sigh.
GUZZIOLOGY has several entries for the Cali’ 3. Depending if it’s Digiplex of Motoplat ignition, Digiplex is BP7, Motoplat is BP6. Note that the letter “R” is missing from these!
Just looked at my Moto Guzzi workshop manual… downloaded from the internet, NGK BPR 6 ES
How much does it really matter?
Groan.
Thoughts on this?
B = 14mm thread
P = Projected insulator
R = Resistor (internal)
6 = heat range. If the manual says 6 then that’s what it is, can’t remember which way the numbers go but 7 might mean either the electrodes will get too hot and burn away, or not get hot enough and foul with deposits. (On their chart 7 is ‘colder’ which I think means the electrodes are smaller, to burn off deposits at a lower temperature. But your engine is in a higher heat range.)
E = 19mm reach (thread length)
S = Standard 2.5mm copper core.
Just IMHO fancy tipped plugs are developed for cars so that they can do 10,000+ miles service intervals, your bike doesn’t need them.
You did ask … 