cylinder head temps.

Posts: 648

If you know what your head temps are for the gy6, please post them here. I would like to get an average. I have experienced a sudden and severe rise in head temp. I am questioning the accuracy of my vapor trail tech sensor or needing to know if I truly have a problem. Any insights in cylinder head temputures?

Posts: 1162

I was never able to get an answer from the trail tech guys on "normal" head temps on the air cooled engines. Mine will max out under hard summer riding. I can't remember if it was 350 or 400 degrees, but that is as high as it will read. The trail tech guy said they cut if off there because of limited computer memory. He suggested I i use the celsius setting for the head temp as that also goes to the same 350-400 degrees. When I get it out again I'll switch to celsius and try to get an "average" and also see where it maxs on a high speed run. If your temp has suddenly risen perhaps you are running lean for some reason. Dirt in the jet, a new air filter, or intake leak.

Posts: 648

Thanks seven, you just made me think maybe I read the numbers wrong , thinking Celsius vs. degree, vice versa Laughing

I reset the trail tech, Very possible I changed the readout without noticing. I got a little panicky because this was a fresh motor, new rings, piston, plug, filters, carb etc. I was wondering what in the world could I have done wrong that would cause this Laughing

I'll set the tech to Celsius also and take a reading. Let me know what you find. Hopefully we will be in the same range.

Posts: 1162

Hey Charlie I just got around to checking this out today. I set the Vapor to Celsius and the air temp was 34. (93F). Went for a ride. I was warmed up and did a 3/4 mile blast at 9,300 rpm and my highest observed head temp was 165C (329F). I did a long uphill blast at WOT, about 6800 rpm max, and was in the 175 (347F)range. The highest temp that I noticed was 185 (365F). I assume that's normal as I didn't melt anything, didn't notice any loss of power, or any other adverse affects. I would have to believe that we are safe up to at least 400F since I would describe todays conditions as "normal". Hotter days and/or more aggressive driving would surely produce higher temps than I experienced today.
Any of you other guys w/ GY6's got a cylinder head temp reading? It would be nice to know what "high normal" is so we could set our warning lights.

Posts: 648

thats good news . it seems that we are in the same range . during normal riding around, I am in the 325 to 360 degree range. At WOT for a couple of miles [9,000 plus rpms] it gets to 375 but hasn't yet to go over that temp.I have turned as much as 10,700 according to the trail tech and never exceeded 375. It does of course reach high temp faster on these hot summer days.The temps obviously have a direct relationship to rpms and stress which we could expect. When I slow down to below 6,000 the motor will cool accordingly. The motor seems to perform best in the 350 to 375 range. I set the high temp warning to 375 and the shift point to 9,500 to let me know when I reached maximum. I am real curious to know just how long a motor would last at 375 plus but not yet willing to sacrifice my motor to find out Laughing

I also have considered trying header wrap to see if that has any effect on temp and performance. Alot of the briggs guys swear by the stuff.