Autolite 4164 is listed as the right autolite for the T. I've had GREAT luck with autolites in BMW oilhead bikes - they have good durability and actually help partially solve a surging problem on those bikes.
I tried the 4164 in my bike yesterday. They came gapped spot on. I put them in and tightened by hand as I have for over 40 years (no torque wrench advice please). Rode the bike for 100 miles and came home. Pulled one out to take a look and found that the sealing washer did NOT come out with the plug, but stuck on the head surface. Same with all 4. The washer is supposed to collapse a bit when tightening and form to a smaller diameter to be trapped on the plug. Did not happen with these. Bought new NGK's and all is well. No more autolite for me.
I tried the 4164 in my bike yesterday. They came gapped spot on. I put them in and tightened by hand as I have for over 40 years (no torque wrench advice please). Rode the bike for 100 miles and came home. Pulled one out to take a look and found that the sealing washer did NOT come out with the plug, but stuck on the head surface. Same with all 4. The washer is supposed to collapse a bit when tightening and form to a smaller diameter to be trapped on the plug. Did not happen with these. Bought new NGK's and all is well. No more autolite for me.
