Perry Pumps and regulators
#78
Senior Member
Join Date: Jan 2004
Location: Almelo, NETHERLANDS
Posts: 2,405

Post not visible, deleted on 7 June 2010.
#79
Senior Member
Join Date: Aug 2008
Location: Grosse Pointe Woods, MI
Posts: 353

My new Venus II has a pretty bad trim change from full to low fuel, so I decided to re-locate the tank to the CG. I bought a Perry pump. My OS120AX has a very nice boss in the middle of the backplate for the preassure fitting. My question is about the fuel tank vent. As this is an aerobatic airplane I will be flying upside ndown and all over the place. Is there a vent configuration that prevents fuel from exiting the tank through the vent. I was told that they make a plug for fuel vent lines that has a very small opening that will allow air to enter but is too small for any significant amount of fuel to escape through. If I use that type of plug with a bleed hole, I would surely need to remove it when fueling so the fuel, when full, has a way of discharging.
#80

Join Date: Jan 2006
Location: Texarkana,
TX
Posts: 64

Try this or something like it. Perry makes one also. This is what I use on a .60 glow and Perry VP-30 pump. I just followed the Perry instructions and so far no problems. It is pumping about 16" from a tank almost on the CG.
http://www3.towerhobbies.com/cgi-bin...&I=LXG869&P=ML
http://www3.towerhobbies.com/cgi-bin...&I=LXG869&P=ML
ORIGINAL: maynardrupp
My new Venus II has a pretty bad trim change from full to low fuel, so I decided to re-locate the tank to the CG. I bought a Perry pump. My OS120AX has a very nice boss in the middle of the backplate for the preassure fitting. My question is about the fuel tank vent. As this is an aerobatic airplane I will be flying upside ndown and all over the place. Is there a vent configuration that prevents fuel from exiting the tank through the vent. I was told that they make a plug for fuel vent lines that has a very small opening that will allow air to enter but is too small for any significant amount of fuel to escape through. If I use that type of plug with a bleed hole, I would surely need to remove it when fueling so the fuel, when full, has a way of discharging.
My new Venus II has a pretty bad trim change from full to low fuel, so I decided to re-locate the tank to the CG. I bought a Perry pump. My OS120AX has a very nice boss in the middle of the backplate for the preassure fitting. My question is about the fuel tank vent. As this is an aerobatic airplane I will be flying upside ndown and all over the place. Is there a vent configuration that prevents fuel from exiting the tank through the vent. I was told that they make a plug for fuel vent lines that has a very small opening that will allow air to enter but is too small for any significant amount of fuel to escape through. If I use that type of plug with a bleed hole, I would surely need to remove it when fueling so the fuel, when full, has a way of discharging.
#81

Join Date: Jun 2007
Location: Simi Valley,
CA
Posts: 972

Run the vent out of the bottom of the cowl. Fuel will not leak out. If fuel is leaking out of your vent line, you have other issues. Do not constrict the vent line (or hook it up to muffler pressure) or you will have problems a-plenty trying to get you engine to run correctly.
#82
Senior Member
Join Date: Aug 2008
Location: Grosse Pointe Woods, MI
Posts: 353

Thanks everybody. I did buy one of those 1 way valves for the vent line, but logic now tells me that the vent line should never have fuel in it unless you are upside down and the engine quits. If that happens we have other concerns than worrying about a bit of fuel spilled through the vent line. I did back the pressure screw off 1/2 turn and I now feel that may have been a mistake as the engine wants to run lean even when I richen it some. I am now able to trail a bit of smoke but only after richening the high speed needle 2 turns from where I had it before the pump instal. The pump does work fine though. I just am not sure whether to increase the pressure or not.[&:]
#83

My Feedback: (8)
Join Date: Oct 2002
Location: Rome, NY
Posts: 7,011

I would say turn the pump reg. screw in a quarter turn and see if that helps.
You should be able to set the high speed NV and peak it...maybe back it off rich a couple hundred r.p.m. just in case...then hold the nose up @ WOT and it should not lean out.
Most of the pump carbs I have or have adjusted for others seem to be set somewhere around a turn or no more than a turn and a half open, when the regulator screw is adj. right. (talking only about the Perry pump carbs )
When you think you're getting close, don't adjust the regulator screw more than about 1/8 turn at a time.
You should be able to set the high speed NV and peak it...maybe back it off rich a couple hundred r.p.m. just in case...then hold the nose up @ WOT and it should not lean out.
Most of the pump carbs I have or have adjusted for others seem to be set somewhere around a turn or no more than a turn and a half open, when the regulator screw is adj. right. (talking only about the Perry pump carbs )
When you think you're getting close, don't adjust the regulator screw more than about 1/8 turn at a time.
#84
Member
Join Date: Feb 2003
Location: Hillcrest, SOUTH AFRICA
Posts: 47

Can anyone tell me how to reset a Perry VP 20 oscillating pump to its original factory settings?
Lynton
Lynton
#85
Senior Member
Join Date: Jan 2004
Location: Almelo, NETHERLANDS
Posts: 2,405

Lynton,
Feeding the engine normally, also connected the oscillating pump and running the engine (and have the pump on nearly same level of fuel in the supply tank) it has to be possible the have a fuel flow in the bottle holding the end of the line 23 cm or lower above the centre of the pump. The head is about 0,25 PSI then, factory value.
The RPM of the engine isn't much important.
This is a method I use myself , but never try this with other brand pumps than own built.
density of fuel is 0.7 of density of water I think. (Nitro?)
.
Success and show me the result when you try the method.
Cees
Feeding the engine normally, also connected the oscillating pump and running the engine (and have the pump on nearly same level of fuel in the supply tank) it has to be possible the have a fuel flow in the bottle holding the end of the line 23 cm or lower above the centre of the pump. The head is about 0,25 PSI then, factory value.
The RPM of the engine isn't much important.
This is a method I use myself , but never try this with other brand pumps than own built.
density of fuel is 0.7 of density of water I think. (Nitro?)
.
Success and show me the result when you try the method.
Cees
#86
Senior Member
Join Date: Dec 2005
Location: Victoria,
MN
Posts: 3,933

ORIGINAL: maynardrupp
Thanks everybody. I did buy one of those 1 way valves for the vent line, but logic now tells me that the vent line should never have fuel in it unless you are upside down and the engine quits. If that happens we have other concerns than worrying about a bit of fuel spilled through the vent line. I did back the pressure screw off 1/2 turn and I now feel that may have been a mistake as the engine wants to run lean even when I richen it some. I am now able to trail a bit of smoke but only after richening the high speed needle 2 turns from where I had it before the pump instal. The pump does work fine though. I just am not sure whether to increase the pressure or not.[&:]
Thanks everybody. I did buy one of those 1 way valves for the vent line, but logic now tells me that the vent line should never have fuel in it unless you are upside down and the engine quits. If that happens we have other concerns than worrying about a bit of fuel spilled through the vent line. I did back the pressure screw off 1/2 turn and I now feel that may have been a mistake as the engine wants to run lean even when I richen it some. I am now able to trail a bit of smoke but only after richening the high speed needle 2 turns from where I had it before the pump instal. The pump does work fine though. I just am not sure whether to increase the pressure or not.[&:]
I then added a T-line so that it would not be soo rich.
This led to a Non-responsive HighSpeed Needle....
I Believe, I ended up with my head gaskets seizing to the head....Not a good.
I ended up getting a replacement....
I then ran a tuned pipe and header... I am currently having issues with it being either lean, or rich...
sometimes rich, to lean... as it goes through the fuel tank....
I may try the perry pump again.
I know the real issue is the OS CARB....THe barrel is too large....
PITA, if you use nothing but the stock muffler...
I hope your results are better than what I had when I 1st tried it....
Perhaps I was too worried about the HS needle only 1turn out...???
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