Interesting question so I looked around and found this thread. It doesn't seem like you have any problems at your temps.
Cylinder head temperature on air cooled engines | Adventure Rider
I've got a spark plug ring temp sensor. Now the trail computer I've got says air cooled engines read hotter than liquid cooled. But it doesn't say how hot is dangerous. I also know that under the plug is probably the hottest point in a air cooled cylinder. All I know is 260 to 300 is normal at trail speeds and upwards of 340 occurs at 55 to 60mph road speeds prolonged for very long. It never seems to act hot as far as metal "tinking" goes, but I also know that those temps in a liquid cooled engine are catastrophic. Does anyone have any "rule of thumb" on this sort of thing?
Very interesting thread. Thanks for posting that.
I too worried after installing a Vapor Trail that had a spark plug sensor. I’ve had it for a month now and find that i don’t look at it every few minutes like I did at first.
Under load, I see temperatures of 320 to 340. But, now I dont worry about it.
I don't have any gauge for head temp., I don't want to know what it is. On a hot summer day, after paddling through deep mud in 1st gear for a half hr. with the cooling fins plugged up with crud, I might not want to do it again if I knew the temp.
2013 Yamaha TW200
1996 Yamaha TW200
1995 Kawasaki KLR650
2002 Yamaha RoadStar 1600 with sidecar
Cool days around 275-300... Hot days running around town etc 325-340 is what I see... I too have the Vapor Trail. The temp reading is taken from the spark plug to head so that is a real hot spot.
Hidden Content 2003 Tw200, 2014 BWS 150, 1969 VW Beetle Baja, 1972 Super Beetle and a 1987 Suzuki Samurai.
I'm glad I'm not the only one seeing these temps from the Vapor trail tech. Thanks for the feedback.