Perry pump setup/adjustment
02-07-2004 | 08:47 PM
#1
Thread Starter
Senior Member
Perry pump setup/adjustment
I just got a perry pump regulator and it didn't come with any instructions - just a pump/tubing and a pressure tap.
I installed the pressure tap in the back of back cover of my .52 2-stroke that's inverted I'm trying to solve fuel siphoning problems and generally not holding any kind of needle settings either high or low despite being broke in now.
I have a 3 line tank, one line to the regulator/carb, one to the bottom of the plane with a fuel dot in it for filling and anoher left open to the atmosphere. I installed the pump in a handmade bracket (the bracket included would never tighten around the pump to keep it from rotating) above level with the carb and a fuel line lenght of about 2 inches from pump to carb (can't get any closer because of the cowl).
Is the set screw on the pump just control pressure? Or does it control pressure and volume? Also which way does what, in for more pressure/volume or out?
Any tips for setting up my engine because running as installed didn't solve much. It still siphons fuel, top end needle seems to be pretty steady but the low end seems overly sensitive one run and then the next run (about 2 minutes apart on the same tank) it seems like the low end needle is ineffective. Idle below 3000 is sketchy at best and doesn't want to settle down for about a 20 seconds after a run up. In a span of 2 minutes idles goes from 3200 to 2800 and then eventuall wiill surge around a bit and sometimes when you let off from wide open it comes down and gets rough then dies. The pinch test didn't result in an overly rich or overly lean condition (at least to me). Engine ran OK before I inverted it and like I said is well broken in already so idle shouldn't be a problem now.
Help please I'm about to go nuts and I don't want to just start adjusting this and that without having a goal or know what's going on.
I installed the pressure tap in the back of back cover of my .52 2-stroke that's inverted I'm trying to solve fuel siphoning problems and generally not holding any kind of needle settings either high or low despite being broke in now.
I have a 3 line tank, one line to the regulator/carb, one to the bottom of the plane with a fuel dot in it for filling and anoher left open to the atmosphere. I installed the pump in a handmade bracket (the bracket included would never tighten around the pump to keep it from rotating) above level with the carb and a fuel line lenght of about 2 inches from pump to carb (can't get any closer because of the cowl).
Is the set screw on the pump just control pressure? Or does it control pressure and volume? Also which way does what, in for more pressure/volume or out?
Any tips for setting up my engine because running as installed didn't solve much. It still siphons fuel, top end needle seems to be pretty steady but the low end seems overly sensitive one run and then the next run (about 2 minutes apart on the same tank) it seems like the low end needle is ineffective. Idle below 3000 is sketchy at best and doesn't want to settle down for about a 20 seconds after a run up. In a span of 2 minutes idles goes from 3200 to 2800 and then eventuall wiill surge around a bit and sometimes when you let off from wide open it comes down and gets rough then dies. The pinch test didn't result in an overly rich or overly lean condition (at least to me). Engine ran OK before I inverted it and like I said is well broken in already so idle shouldn't be a problem now.
Help please I'm about to go nuts and I don't want to just start adjusting this and that without having a goal or know what's going on.
02-08-2004 | 02:29 PM
#2
Senior Member
RE: Perry pump setup/adjustment
I think you're trying to solve one problem (poor idle on inverted four stroke) with another (fuel pump). Here's what I know:
The Perry PV30 is a pressure regulated pump. The adjustment screw backs-up a spring that controls the pumping diaphragm (I'm unclear as to exactly how the pressure/volume control works). Turning the screw in (clockwise) increases pressure. The plumbing that you used is correct. Unfortunately, if your tank is higher than your carb, I don't believe the pump will have any effect on siphoning.
Getting an inverted four stroke to idle well is a challenge. I would lower the tank to start with. Try an O.S. 'F' plug. As a last resort, you can try an onboard glow igniter that switches on at idle.
Good luck.
The Perry PV30 is a pressure regulated pump. The adjustment screw backs-up a spring that controls the pumping diaphragm (I'm unclear as to exactly how the pressure/volume control works). Turning the screw in (clockwise) increases pressure. The plumbing that you used is correct. Unfortunately, if your tank is higher than your carb, I don't believe the pump will have any effect on siphoning.
Getting an inverted four stroke to idle well is a challenge. I would lower the tank to start with. Try an O.S. 'F' plug. As a last resort, you can try an onboard glow igniter that switches on at idle.
Good luck.
02-08-2004 | 04:44 PM
#3
Thread Starter
Senior Member
RE: Perry pump setup/adjustment
I'ts not a 4-stroke. It's a 2-stroke.
I guess I'll have to call perry for a set of instructions since I got it new from Tower and it came without them. No one really seems to know if the adjustment adjust pressure or pressure and volume etc...
I guess I'll have to call perry for a set of instructions since I got it new from Tower and it came without them. No one really seems to know if the adjustment adjust pressure or pressure and volume etc...
