Cylinder Head Temperature gauge

Roofaloof · Post by **Roofaloof** » Wed Apr 30, 2014 7:02 pm

Does anyone use a CHT gauge? If so, where did you mount the sensor?

I'm unable to mount the sensor on the gauge I bought due to clearance issues around the spark plug.

This: http://www.trailtech.net/digital-gauges/tto/72-et1

I then chopped the ring off and JB welded the probe to the head. This worked for a short period of time, then the epoxy broke off.

I'd really like to monitor CHT since I boosted compression. Any ideas would be appreciated.

jrsjr · Post by **jrsjr** » Wed Apr 30, 2014 7:52 pm

It's a shame that ring rig didn't just work. That would have made it really easy. I suggest you look around for another ring rig that fits. The Kart guys have sources of high-performance parts. A lot of them are running GY6 derived motors so they might have a sensor that fits. Here's a pic of one that looks promising. I found that on a Dutch Kart site. There are bound to be US-based Kart suppiers who can source something like that.

The not-so-easy solutions that I'm aware of all involve welding of the non-JB variety to weld a bung onto the cylinder head so that you can screw a sensor in.

BuddyRaton · Post by **BuddyRaton** » Wed Apr 30, 2014 11:48 pm

Did you remove the crush washer from the plug? You may also need to trim a fin or two to get it to fit. The plug is the best place.

lovemysan · Post by **lovemysan** » Thu May 01, 2014 1:12 pm

I'm running a 10mm trailtech sensor on my buddy 125. I tried it without the crush washer but it leaked a little so I put it back on. It takes a little extra care to get it installed but it works fine. I run the lead right through the spark plug hole. The boot will snap around it just fine. I will say that all the gy6 tuning info I could find didn't correlate to my bike. On total ruckus this consensus was tune the bike to run about 375/390f. The hottest I've managed was 345f and at that point power was falling off. I like to stay below 330f for best power. I'm also not sure my gauge is a 100% accurate. It is consistent though. I find the wideband is much easier to tune with.

Roofaloof · Post by **Roofaloof** » Thu May 01, 2014 8:49 pm

Before mine broke off, my highest temperature was 220F. It's possible that the epoxy insulated the probe somewhat to lower the readout temperature.

I was running the temp sensor epoxied into the area I machined next to the spark plug hole. The machined area can be seen in the below photo.

I have another issue I have with the 10mm ring sensor. I nicked the top spark plug sealing surface while working on the head. (can be seen in the above photo) I don't believe that I'll be able to seal the combustion chamber with the ring terminal.

Luckily for me, the NGK Iridium plugs use a conical seal. This bypasses the top surface that I damaged. I've been using one of these plugs with no issues.

I'm thinking I'll pull the head and just do a better job of JB welding the sensor in place.