Piston/bore clearances at operating temp?

[Max Preload]

You're right about the relative crudity of bike cooling systems. My KLR has a thermostat and waterpump, but the operation of the 'stat means the temperature bounces between hot and cool as the water flow starts and stops.

Drill a bigger hole in the thermostat base plate to allow greater coolant by-pass. It stops the temperature cycling by smoothing the flow through the radiator.

[pete376403]

Yeah but then it takes much longer to warm up. The KLR never gets to even halfway on the temp guage as it is, too much cooling capacity. I've blanked off half of the radiator and on Saturdays South Coast adv ride, even when chugging in deep sand, the guage needle didn't move very far

[Max Preload]

Yeah but then it takes much longer to warm up. The KLR never gets to even halfway on the temp guage as it is, too much cooling capacity. I've blanked off half of the radiator and on Saturday's South Coast adv ride, even when chugging in deep sand, the gauge needle didn't move very far

It takes marginally longer - I'm talking a maximum 3mm hole - it's common to do it on cars that suffer the same temperature cycling problem.

Don't use the temperature gauge to gauge temperature... I know it sounds insane but they rarely give any useful indication of the actual coolant temperature in a similar way, but for different reasons, that you shouldn't rely too heavily on fuel gauges.