I am setting up the P-51 PTS with the magnum .52rfs. How does one go about pressure for the fuel tank? I assume the nipple on the bottom of the crankcase?

No, that is the crankcase vent. There should be a nipple on the muffler for pressure. If you are running a straight pipe with no muffler, no pressure is needed.

For that crankcase vent, it will spit some black gunky stuff (Technical term). You can put a piece of fuel line on it and vent it outside of the cowl if you want to keep things clean in there.

No, that is your breather for the crank case and it needs to have a line on it just long enough to get out of the cowl. It will drip oil and it best if it drips out of the cowl. It assures that oil circulates into the cam/front bearing. If you plug it, you shut down your lube path. Generally the engine won't run well enough to let you use it for long with the vent plugged. Some of the larger Magnum engines run this line to the intake manifold, but I wouldn't try with the 52. The carb system is designed around either a vent to the manifold or not, and the Mag 52 is a not.

There is a nipple on the muffler that goes to the vent line on the tank. You just use a two line hookup, same as for the two Strokes.

Don

It has a muffler like the one for the 52 surpass, no nipple however. Should I install one??

And thanks guys, I would have been pumping junk from the crankcase into my fuel, glad something about it did not seem right and I asked here. RCU ROCKS

Did You just get this engine?? Let me go out and check my two that I got on the Hobby People Sale a while back. You really need the pressure for good fuel flow to the carb.

OK, I just checked both of the engines I got a couple months back and both have the nipple in the muffler, same as my older one and my O.S. 52 Surpasses.

If it is a new engine, I would contact Hobby People and tell them you need a muffler, yours is defective.


Don

It is an older engine about 4 years old I think, and it was sent to me from my uncle who no longer flys glow. I soaked it and had to free it. First start on the stand was yesterday. I have a bulb out there to move fuel around and prime the engine. I did not even think about it not having the exhaust pressure. It is the first four stroke I have messed with (obviously)

You can also get a Dubro nipple for the muffler which would require you to drill and tap a 8/32 hole for the nipple. Might be a bit cheaper than the whole muffler. Good Luck, Dave

http://www3.towerhobbies.com/cgi-bin...?&I=LXD623&P=7

You could drill and tap a hole for the nipple. It goes into the tapered part between the pipe and the wides part of the muffler. I'm not sure what the thread size is, and It may not be important other than to get a hole that the nipple threads will bite into. I don't think this is thick wall aluminum at this point. If you decide to relace the muffler, and could find an O.S 52/61 muffler, it would be my first choice, they have a baffle in them and give slightly more tank pressure.

Don

thanks for the help guys.

You may not need it I suppose. I have an Enya 1.20 4-stroke that also doesn't have a pressure tap on the muffler. At first, I was a little confused as to how the tank would be pressurized, but it starts easily with an electric starter and has no problem with supplying fuel to the carburetor in flight.