Modern Buddy

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.

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.

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.

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.

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.