Overheating issue

[sonnyjim]

Hi all.

I'm still in the process of getting my bike road worthy.

I can now get it around the block. One concerning thing is it seems to get to the H in about 5 minutes of cruising around the block in fairly cool temps (16 degrees). I am thinking thermostat, though I had installed a new old old stock one. Otherwise, I guess waterpump?

Any ideas on how to check or determine which is the issue? Do the waterpumps ever fail in such a way?

Secondly, anyone know if a thermostat I can get from auto parts store that might fit?

[karl pa]

Does the engine actually get hot or just the gauge shows hot. You should first verify the engine is overheating, if it is it could be several things.
On the kettle clinic, they recently covered gauge malfunction, they say to check the pilot bulb earth connection.

[sonnyjim]

Does the engine actually get hot or just the gauge shows hot. You should first verify the engine is overheating, if it is it could be several things.
On the kettle clinic, they recently covered gauge malfunction, they say to check the pilot bulb earth connection.

Unfortunately my infrared thermometer was malfunctioning. But I would say the engine did feel very hot to touch after these 5min of riding. I couldn't say the actual temp.

Should the upper rad hose be hot? I presume it stays cool until the thermostat opens?

[karl pa]

Yes the upper hose will stay cooler till t-stat opens. You can remove the t-stat and run without to check if still overheating. It could be the water pump vane isn't pushing water properly, maybe an issue with the key or pin that connects the vane to the water pump shaft, may be a problem with the nylon gear that turns the water pump shaft. but again I would verify that it actually is getting hot before tearing into to much.

[sonnyjim]

Yes the upper hose will stay cooler till t-stat opens. You can remove the t-stat and run without to check if still overheating. It could be the water pump vane isn't pushing water properly, maybe an issue with the key or pin that connects the vane to the water pump shaft, may be a problem with the nylon gear that turns the water pump shaft. but again I would verify that it actually is getting hot before tearing into to much.

Thanks Karl. I verified that my infrared thermometer actually is working properly and took the bike for a ride(vid attached). You'll have to ignore my driving (and fuel set up), but towards the end of the video I start to check temps (after the needle went off the scale, and then quickly dropped after turning the bike off).

Essentially, the engine was reading about 60-70 C. But the temp needle was off the chart. The upper rad hose was still more or less ambient temp. So the thermostat definitely had not opened - which makes sense if the temp was only 70. The only part that was really hot (130C) was the point where the barrel meets the exhaust. The exhaust header themselves were only 55-60 (middle was 70).

https://youtu.be/DHnqRD_DcOQ?si=m_Z_lk-M6aTLyjZB

EDIT: I took off the chrome cover of the dial. I found that someone had taped electrical tape around the bulb socket body so it wasn't in contact with where it slips into the housing. I am not sure if that was the issue... However, with that tape removed, the the needle now moves up passed the half way point as soon as i turn the ignition on (cold engine)... EDIT 2: The wires to the gauge were reversed! I guess the PO had the issue and put tape around the bulb socket, which kinda fixed the issue, but not really. People on FB suggested the wires were versed, and voila!