Perry Pump and 2 stroke engine
 

What is the proper way to hook up a Perry VP 30 pump. I read the instructions, but they are not very clear.
I did a search and found some info.
My main question is does the tank have to have to an open vent line all the time?

RE: Perry Pump and 2 stroke engine
 

very simple hook it up to crank case pressure you will have to drill and tap an pressure fitting on the backplate, on my OS 160 I used a pressure fitting for the OS 140 and drilled the top left backplate screw with a 1/16 bit, one fuel line from the tank to the pump then to the carb I use a 3 line tube tank one for fill and the other is vented to the atmosphere, what engine are you using the perry pump is very good once set, theres nothing else to do, have 100's of flights on mine and no problems at all

RE: Perry Pump and 2 stroke engine
 

Answer to your main question is Yes, vent line open all the time, otherwise the pump would be sucking on a vacuum, which would bring everything to a halt pretty quick. The Perry pump does operate by suction by the way, not by pressurizing the tank like some other systems.

I've had good luck with Perry pumps, solved a few difficult installations for me.

I tend to prefer the 'bypass' plumbing arrangement. This has a tee installed between pump output and fuel inlet to carburetor, and results in excess fuel pressure being diverted back to the tank, where it displaces air which either goes out the vent or equalizes the volume being drawn by the pump. In any event, it provides very stable fuel pressure or head at the carb inlet, no matter what the model's attitude or G-forces (within reason, anyway).

Good idea to run the vent line above the tank, then exit to atmosphere at a point on bottom of plane, behind the tank. This way no fuel drains out as the plane goes through a loop or other maneuvers. Also a good idea to put a fuel filter in the vent line, to keep crap from being sucked into the tank through the vent line.

I've been in long arguments that have never been won concerning whether a running engine with pump operating can ever leak fuel out the vent line. I do what I've seen other good flyers do, works for them, works for me.

RE: Perry Pump and 2 stroke engine
 

The above posts are right on. In addition I put a one way valve on my vent line to prevent fuel from running out the vent. You do have to disconnect it in order to fill the tank.

RE: Perry Pump and 2 stroke engine
 

Thanks for all the info. I will be running it on an OS 160.

RE: Perry Pump and 2 stroke engine
 

I don't know the vintage of your OS160, but the one I have came with a flat backplate. I looked on Tower and was able to order a newer backplate with a boss in the center to accept a pressure fitting. You can drill and tap the flat backplate, but most folks are more comfortable with the special boss. The Perry pump and the 160FX are a very compatible combination.

RE: Perry Pump and 2 stroke engine
 

I wouldnt tap the back plate, just take out the upper left backplate mounting screw and drill a hold through the case, and use the pressure fitting for the OS140, you can ge the fitting for about 5 bucks through towet hobbies, and its the same tread as the mouniting screw, but I do know some people have went the back plate route, but it is very thin

RE: Perry Pump and 2 stroke engine
 

Jon Lowe has very good set up for the OS 160 and perry pump combo, maybe he will jump in here and add some comments

RE: Perry Pump and 2 stroke engine
 

Thanks, I have the newer style backplate, except the boss you are talking about is at the bottom of the case. I had to fill it with JB weld then drill and tap
to get it to work. Should be fine now.

RE: Perry Pump and 2 stroke engine
 

Yes Jon Lowe has a OS1.60 Cookbook that he will send you , Lots of great info.

RE: Perry Pump and 2 stroke engine
 

Good discussion here.

I have a ST 2300 that I've always had troubles with. The engine is inverted on the plane. Using the single tank with muffler pressure in and a standard line from the tank to carb, the plane will deadstick quite reliably. I tried a header tank and it helped but didn't solve the problem. I recently purchaced a Perry pump and installed it. The pressure fitting is in the center of the backplate. I'm still using muffler pressure. I also have a bypass installed between the pump and carb returning to the tank through a check valve. At first the engine was very difficult to tune. It would flood out very easy. I worked on the carb until it was running very well and took it for a flight. After about two minutes another deadstick. Three or four times of this and I decided on trying a Perry carb. The Perry carb instructions say to move the idle dial very slightly, 1000th of an inch. They aren't kidding. It is VERY touchy. After two days of tuning I got it to run pretty well. I took two flights and had two deadsticks. The deadsticks are under half to full throttle and usually about two minutes into the flight. The tank and lines are good, no leaks. I tried an Idle Bar plug and it helped a bunch on the transitions from idle to full trottle or mid to full throttle. On the ground I'm not really having any troubles. It's just in the air when it quits.

Ideas?

Thanks

Tim

RE: Perry Pump and 2 stroke engine
 

OS F plug
Use crankcase pressure. Don't use muffler pressure.
(ST 2300 only--not other makes of same size)-----no more than 12% synthetic oil---if you know what you're doing ie no lean running.

RE: Perry Pump and 2 stroke engine
 

Email me thru RCU, and I will send you a copy.

Jon

RE: Perry Pump and 2 stroke engine
 

I ordered som F glow plugs and will try it without the exaust pressure line. Will report back in a week.

RE: Perry Pump and 2 stroke engine
 

why can,t i use exaust pressure to power pump

RE: Perry Pump and 2 stroke engine
 

it wont produce enough pressure tp make the pump work properly

RE: Perry Pump and 2 stroke engine
 

I threw in the towel on mine and bought an OS 1.60. The OS runs great without the pump and the EBAY sale of the ST with the pump paid for the OS. Now everybody's happy.

Tim