I did some testing over the weekend....
Water temp gauge reads correct, so engine is definitely overheating.
Checked operation of thermostat and it opens, as it should at 55-60*.
Tacho reads correct when read against an optical rev counter on the propeller, so engine is not developing full revs.
Changed out sparkplugs and all 4 are a nice tan colour - very consistent across all plugs.
Also, at the suggestion of Poll, I changed the oil in the reduction box to a lighter grade - no change unfortunately.
So Riley, expect a call chasing those radiators so I can check if they will solve the overheating problem! Get the coffee ready!
Spoke with Gary Flood today - he has suggested I check the main jet size is 165 which he says is what it should be. He also suggested checking to ensure the needle jet assembly is located beneath the white plastic guide at the top of the carburetor.
All of these will be tried next time I'm at the hangar - not for a few weeks now probably:bad_mood:
Any other suggestions you have will be tried if at all possible, or at least thought about:dizzy:
Pud