# Removing Impeller off a Monarch Water pump



## johnnyo (May 17, 2012)

I have an older Cast iron Monarch water pump with 1 1/2" inlet & outlet.The pump is directly connected to a 3hp Briggs & Stratton motor.. 
It didn't pump very good, so I took it apart (4 bolts), & the impeller is not very good, & the housing is worn from the impeller.. The impeller is threaded onto the end of the B&S crankshaft.. Can anybody suggest the best way to remove the cast impeller?? I have a spare pump housing & a pretty good cast impeller that I can mount back to this motor, but I'm stumped on removing the old impeller. Is the impeller left or right hand thread?


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## farmrbrown (Jun 25, 2012)

You can look thru here to see if one of these match your model.
http://www.riverbendind.com/MiscPDF/Monarch-NT.pdf
Generally they are standard threads, but if you know the rotation direction, you can bet the threads will go in the same direction, IOW so it wouldn't loosen as it was running.
Other than that, lots of penetrating oil and a few sharp blows to loosen it up.


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## agmantoo (May 23, 2003)

From the parts breakdown pdf posted by farmrbrown three different models are represented. Some of the models have a stainless steel bolt retaining the impeller. The versions with the bolt have a key in the shaft and are not threaded into position thus a puller would be required.


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## farmrbrown (Jun 25, 2012)

Thanks, I found the drawings but didn't have time to go thru each one......and I gotta run again.........:hobbyhors


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## johnnyo (May 17, 2012)

thanks for the replies.. Mine has the Impeller threaded on.. No keyway.. I can't get it loosened at all, & there's no way to stop or hold the crankshaft from turning short of dismantling the engine..


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## agmantoo (May 23, 2003)

Some folks will remove the spark plug and feed in a piece of rope and then rotate the piston to where the rope is compressed against the head thus causing the crankshaft to cease to rotate. There is risk of engine damage.


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