Lake water pump low pressure

[Rman]

I live lakefront and have a shed 8 feet above water level. To it I have a 3/4 hp single 1-1/4 inch pipe to a foot valve which is 2 feet below water level. The pump is 12 yrs old starts right up but with 100 ft 5/8 inch hose pressure is low about 25 psi where the sprinkler is attached must be moved around all day. The water is for irrigation only. Worn out pump or asking too much for its age. Drained for the winter each year. Would a larger pump 1HP bring up the pressure to about 50-60 psi. Currently pump has a 2 gal pressure tank and it holds. The pressure switch came attached to the pump and can only set cut off pressure set at 40 psi any higher and the pump will never shut off
Thanks

 

[Bgard]

Does the foot valve have a screen on it? If it does have you checked to see if it is plugged up? If no screen the impeller in the pump may be plugged up.

 

[Sponsor]

 

[Reach4]

A 1/2 inch submersible in the lake would give as good or better characteristics than a 1 HP jet pump. No priming. But it needs power.

 

[Rman]

Does the foot valve have a screen on it? If it does have you checked to see if it is plugged up? If no screen the impeller in the pump may be plugged up.

There is a screen but being in shallow water there is a lot of weed debree
How would I clean out the pump?
Would forcing a backflush with house water hose work?
Thanks

 

[Bgard]

I don't know about your pump but most have some means of removing the motor and beating assembly out the back of the pump head. Send pictures of pump