Sprinkler pump replacement help

My sprinkler pump decided to stop working right as it us warming up here. The pump side is probably ok, the motor died. Probably best to get a whole new one as mine is most likely close to 30 years old. 

Problem is that I have no idea what hp I need. Home Depot has them in different hp flavors, but they are all plastic bodied, not sure its the best. 

I am pulling from w shallow well, and pushing throughout 1/2 acre. Six zones, longest run is probably 300-400 ft if I had to guess. 

Any recommendation? My pump is so old that all the markings are gone, except “C76-49B” on the pump body, the motor label is gone. 

Some pictures of the actual set-up:

How many spray heads run at once in your system? What is their flow rate and recommended pressure? From there you need a pump that will hit those numbers plus a little. 

In reply to Toyman! :

I have no idea how many heads on each zone.

I understand HP has nothing to do with flow, but I am assuming the higher the HP is used to support a higher flowing pump. So let's say I buy the 2hp from HD and I only needed a 1hp ... what could happen? The pump dies prematurely due to the higher back pressure its seeing?

You also need to consider how deep your well is. Flow rates fall off fast as lift distance increases. 

In reply to Slippery :

The pump won't die, but it will be pretty inefficient. Most pumps have a performance curve like this. Ideally you size the pump to run in the middle of it's curve. 

This is the best I could find on the Everbuilt 1.5 HP pump that HD sells. 

You need a pump that will hit the system pressure at the GPM the heads require for proper operation. At a guess, you need to hit 35 psi at a flow rate of 2-4 GPM per head. So if you are running 10 heads, you'll need a pump to put out 30ish GPM at 35 PSI when pulling the depth of your well. 

One thing an oversize pump may do is short cycle. You don't want the pump to cycle on and off continuously. Ideally, when the sprayers are on, the pump should run continuously and be able to maintain system pressure. 

According to this exploded view, your pump is a Berkeley/Stay-Right 1.5 hp #FP5242-08. Part number 9 is the pump body which matches the number on your pump. 

https://www.waterpumpsdirect.com/manuals/flotec-a40b409866a6fdf2966dbd495b2edd82.pdf

I was just looking at that, makes sense.

The only thing is that the motor is two phase ... 230/60. I wonder if someone changed it before.

This gets me in the right path, thanks! Might just order a new motor and test it out.

If nothing else, a 1.5 hp pump should be close enough to what you have to do the job.