How much water flow?

How much water should the impeller pump? I took the water inlet off at the thermostat housing and started the motor on muffs. at idle the water barely over flows out of the hose. (the hose is pointing straight up ) at 2500 rpms the water shoots up about an inch and a half. it just doesnt seem to be enough flow. Ive had the impeller apart and checked the power steering cooler and all is good. the problem im having is overheating at idle, running at normal temp at 1500 rpms, and overheat at anything over 1500rpms. what do u guys think?

Re: How much water flow?

Ive had the impeller apart and all is good.

Click to expand...

I assume that means all the vanes straightend out after a few minutes? If not, you should have replaced it.

Re: How much water flow?

So if the veins dont straighten out after a few minutes, then it needs replaced? when i said all was good i meant there were no nicks or missing peices of rubber missing and the housing was smooth, the veins were flexible and the tips did not seem worn. I didnt leave the impeller sit out of the housing long enough to see if the veins would straighten out. But im just going to get a impeller kit and change it, just to eliminate it as the problem. I have another mercruiser boat with the alpha one and i checked the water flow on that one and it seemed to me that it flowed alot more water from the inlet.I just like to determine the cause of the problem before i start throwing parts at it. I guess i assumed that since the previous owner had the impeller serviced last june that it was ok. The PO told me that he put maybe 10-15 hours on the impeller but you know how that goes.

Re: How much water flow?

Ayuh,... At almost a year, it should be Ok, but when you drop the lower, Flush it with your garden hose, from the T-stat, Back to the impeller...
You might find some debris that way...

Re: How much water flow?

Ok, I will try that.

Re: How much water flow?

check your belts for tightness maybe slipping at higher revs happened to me