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Thanks for the info. I'll try a new impeller. Why would that cause the problems I mentioned?
Have you checked the thermostat?Post picture of old impeller ?----Compression test is now a good plan as well.---Post your numbers here.
South West AustraliaInstall a new impeller ------water pump kit 432955 would be a good start.-----Your location ?
Thanks for the reply.( In regards to running one cylinder at a time with the timing light. ) Is this done by disconnecting the other two spark plug leads and is it a problem for the engine? Would this also be the way to set the mixture screw for each individual cylinder?Test the sensor switch.-----Are you 100% sure that S.L.O.W. is the issue?----Tried running with timing light one cylinder at a time.----Also post compression test values.----Perhaps run with a different tank and hose as a test.