I have a 2001 force 75. The water pump started not working well at idle but would work fine at speed. I replaced impeller and still have same problem. At idle there is very little or no water from the pee hole but any throttle produces a stream but does not seem to get full force even at full throttle. How do I check for blockage internally and where?
D. Willis Louisiana

I have been worried about water not pumping due to the indicator. Sometimes, you can blow into the indicator or use a fine wire, and it will dislodge the dirt and start indicating correctly again. Has worked many times.
Good luck

Thanks for response. I've blown out tube and was wondering if debris could get caught inside thermostat housing or internal ports.