Cylinder head temp

[RustyRD]

I have installed a koso meter on my RD350, and it has the capability of providing CHT. I was curious if anyone has run a gauge with CHT and had a range they have observed.

[NYSingh]

I use these numbers posted by 1976RD400C as a baseline for judging whether my head temperatures are in the right ballpark:

Here's what my CHTs read on my stage II 400 with B9 spark plugs
       start up and go putt putt for 1.5 miles        160
       back road cruising                                     275
       hooligan                                                   335
       took it to a few track days                          310   maybe because it has more air rushing past the cylinders
       max I ever saw                                         340

     Noticed there can be up to 15 degree variance between the 2 cylinders and can't figure out why. I think because the sensors are touching the actual spark plug there may be a slight difference in way the plugs shed heat??? Maybe I'll try switching the plugs and see if the symptom follows???

http://www.2strokeworld.net/forum/index.php?topic=1752.msg16164#msg16164

[RustyRD]

Thanks for the info, , just what I needed is some point of reference , my meter only has one temp input.

[Alain2]

I ran my Daytona Special (factory CDI with b9es plugs) between 320-365f all summer. Goes up to 385f on the biggest climbs.

My RD400c with points runs 20f cooler.

EGT, plugs and piston wash are good on both bikes.

[RustyRD]

Thank you for including the plug heat range.

[dusty350]

If you buy the Koso Mini 3 unit, it has 2 temp take offs, so you can cycle between both cylinders;

20201206_205315 by dusty miller, on Flickr

;D

[sav0r]

I know this is an unpopular opinion, but cylinder head temp is worthless even with good data logging capabilities. There are too many variables to make it worth using.

[m in sc]

I know this is an unpopular opinion, but cylinder head temp is worthless even with good data logging capabilities. There are too many variables to make it worth using.

I agree... its good for overall trends,  but egt way more accurate and real time. by the time a plug sensor shows a problem, prob too late, especially on an air cooled motor.  my .02

[RustyRD]

Thanks to all, the Koso meter had a temp function so I decided to use it. Did not make the meter purchase for the temp, however it was there. Thanks To all who gave me input. :clap:Happy Hew Year

[m in sc]

makes sense, I'd probably do the same if I had the guage as well..

[pidjones]

Hope you don't mind a question added to an old thread. After my initial seven mile loop (varying the RPMs up and down to break in the new rings), I parked, shut off the bike, strolled into the garage and dug out my IR gun. Downpipes were only ~90 F, exhaust flex joint 160, and heads 220. Nothing really high, but I wonder if the low downpipe temperature is normal, inaccurate due to the reflective surface, or grossly abnormal.

[Striker1423]

Head pipes are thin. Exposed directly to air and you didn't ride all that far really. Heat soak is a thing. I wouldn't worry too much about it.

[RustyRD]

With the biomed work I do, some readings taken with IR vary depending on the surface. I have noticed a large variation between contact probes and IR on shiny surfaces.