I was into R/C when I was a kid (now 35) and when I was 12 I built a Great Planes PT20 trainer. I flew it a couple times with the help of an older flyer but I never managed to get proficient on my own and after I went to college it ended up in mom's garage.

Long story short I have the plane back now and am wondering if it is worth trying to get it back into the air or not. It has an OS .25 engine in it, it turns over freely but I am curious if an engine that has sat for 20+ years would even run still? The rudder and elevator are broken and the ailerons seem to need some work as well. The radio I know is all probably junk as it is really old Airtronics stuff on AM band, not sure if even the servos could be used still or not.

I know my construction skills were a bit underwhelming when I was a kid, but it still seems solid. Does the glue or balsa rot over time? Would I be better off just starting with an ARF and a new radio or do you think it is realistic to get this thing going again without too much expense?

Hi

Well I think its worth a shot. Fix the obvious, do a little pulling and tugging on the airframe to check its sturdiness, get a new radio set and install, Re-due your fuel system (age!), test run the engine, and go for it. Also Join a club and get some help and flying instruction. You meet a lot of nice people at most clubs.


Vince

When you re-do your fuel system, that includes a new stopper in the tank and a new clunk line

If the plane is in one piece, flyable, go for it. Why waist a perfectly good trainer?? As for the engine, make sure and run it, and make sure its running good before taking to the air. Like they all said, replace fuel line pieces, check all radios systems, and if you don't remember how to fly at all, seek an instructor to help you out, have a good time.

Make sure the engine will run a full tank of fuel through

Nope that stuff will be good for nothing. I'll give you my address,let you ship it to me and i'll dispose of it for you.

I did the exact same thing a couple of years ago when I turned 30. I decided to get my old trainer from my parents basement and learn to fly it. I replaced the batteries in the plane and transmitter, replumbed the tankand took it to the local club where they were happy to teach me to fly. Jump forward a couple years, and I now have 4 planes flying and 4 planes waiting to be assembled and am loving every minute I get to spend on this hobby. By the way I flew the trainer last saturday just for the fun of it. It still flys great and I love doing touch and go's with it.

I'd also suggest that you use a simulator for a while before getting her up. FMS is free, and can be connected to your TX. I would be good training for finding/using all of the controls on the TX. regards, Rich

I would just update the radio system and go for it.

Set it up, put it on a table and look for any obvious warps....then run the motor.

Is the OS motor a ball bearing or a bushed engine?? My guess is for that trainer it would be a Bushed motor...the LA series I think.
Nothing goes "stale" in an engine like that...If I were you I'd run it and fly it.

Thanks for the great input guys, I am going to get some fuel and try to set the engine to run when I have a chance and if it seems to be ok I'll look for a radio to replace the old one. The carb on the motor seems a little sticky, is there anything special I should run through it before starting it up? Would automotive carb cleaner hurt a nitro engine?

The fuel will be fine.

It might attack the plastic parts...look over those on the carb. Make sure the little Oring on the needle is intact....also stuff like the gasket between the carb throat and crankcase.

Just pour fresh fuel on the carb to loosen it up..it'll be fine

The trainer my son and I learned on sat for 5+ years in a dirty, dusty environment. It' took a bunch of cleaning and a little bit of replacing, but it flew great, until my son had a mid-air with it.

jack

<span style="font-size: medium"><span style="font-family: Comic Sans MS">after a while of sitting anywhere, even in a box that "shouldn't" even collect dust, i like to take the carb and muffler off and flush them out really good with denatured alcohol, squirted through a spray bottle in a nice stream so you get a little pressure. let it evaporate for a few minutes (wearing gloves and glasses of course while using it; it's very nasty stuff if you get it in your eyes or cuts) and after everything is dry again, it will be completely de-greased and de-funked from the years. you can buy it at home improvement stores.then get you some after run oil and take out the glow plug and put a couple drops in the chamber and in the carb, and turn the motor over a few times by hand to make sure it circulates around good and coats everything. then put your glow plug back in.the stuff is like penzoil for your car. then do the same every couple of flights (especially after those not so desired "controlled" ditches), and you could probably get another 20+ years out of it. i second the fuel system replacement. i would probably do the tank too, but that's just me. i'm picky about brand and style. i use the denatured alcohol on everything i clean though. the stuff is awesome. even removes permanant marker.</span></span>

likely the rubber stopper is toast as well. But if the plane was built well it should be fine.
Watch out for brittle plastic parts such as hinges and clevises and horns. Repairing and recovering or patching is just part of this hobby so no sweat. The motor is well worth keeping.
The motor may need a new O ring or two, Needle valve and under the carb.
NO on the automotive carb cleaner it will eat the O rings.

Took the motor out last night and the carb was indeed gummed up, didn't open and close freely. I used a little WD40 and got it working and then cleaned it out and also used some compressed air to get the dust out of muffle/cylinder and put a few drops of oil in the cylinder to get it spinning freely. The glow plug looked like it had some funk on it and the fuel tank had some old crud as well so I'll grab those and some fuel today and try to fire it up tonight. It definitely needs some repair to the rudder and a couple of the linkages but otherwise just a little TLC and some monokote should do I think. Thanks for the advice I'll keep you all posted on what happens.

Some photos would help. Ihave had good luck getting very old glow engines running. They usually only need a good cleaning and a little sealer here and there.

Last year I revived a trainer that had been sitting for about 25 years...

I did the following;
- cleaned the engine (a Veco 19) and carb using fuel, ran it on a bench (much easier to tune and find problems), found that it needed a new plug and ran fine after that.
- replaced the wooded prop (it had a tiny crack)
- replaced the complete tank and all fuel lines
- replaced the batteries in the transmitter and for the receiver

After that it flew again with the original AM radio and everything, not many are using AM so it seems very quiet now...

I would recommend that you at least check the radio and servos before investing in new stuff, it is nice to have an all vintage plane. The only thing I miss from a modern radio is the memory for the trim (and the model memory for several planes). Expo and dual rates etc are not really necessary, to me anyway, I find that I don't really use it on modern radios either.

I understand the crystals in the transmitter and receiver can degrade with age and should be replaced periodically.