I am new to the sport. Only about 4 months of flying e every few weekends. Enjoyed it so far until my engine problems. Started with a hanger 9 p-51 pts. Great plane. I had engine problems and changing a glow plug and it seemed to fix it. Only had about a gallon of fuel through the thing. I got a second plane hanger 9 arrow 40. Fly's great. I got the basic and put my own flight pack and engine in it. A thunder tiger 42 that my brother got about 4 years ago and only ran a few tanks through it. It has set in his garage until now. I put it on my plane started it up and it ran great with no adjustment over a dozen flights. Now about 10 tanks into it I flew it last weekend for one flight brought it in, fueled it for the next run and then the problem started. I am having the same problem as my p-51 except that changing the glow plug does not fix it. Put a brand new one in it and was doing the exact same thing. Will run fine with glow plug starter but as soon as I remove the starter it dies. Sometimes after I remove the starter it will continue to run at mid or full power but only for maybe 10 seconds, but it does not sputter, just an abrupt stop. It has smoke coming out of the exhaust and at full power with the starter on it I turn the needle rich until it bogs down a little and back it back a turn or 2 until it starts running good. Am I doing something wrong? Can it be a fuel problem as far as fuel going bad? Is the engine loosing compression? Are glow plugs that damn sensitive? Any help will be greatly appreciated. I thought about taking it to the rc shop and let them try to fix it but would like to figure this out myself and hopefully make this a cheap fix. The only thing I can think of is to try another new plug, but I have already tried another used plug as well as the new one and did the same thing, so not sure that another new plug is the fix. Hard to believe an engine this small is this big of a pain. Thanks!

Ok, as I see the problem I would say that it's a good chance the problem is your fuel. This happens every now and then when an engine (or engines) just start running bad. It usually turns out to be moisture (or foreign matter) in your fuel jug. Open a fresh jug, or even get a tank of fuel from someone else, and see if your problems don't go away. If they do then you need to pour your old fuel out and open a new bottle.

Hope htis helps

Ken

thanks i will give that a try. I do keep the fuel jug in the garage where it is somewhat humid with one of those fuel caps on it that you can connect your fuel line to for easy fueling.

It's possible that you picked up some moisture in your fuel.

Ken

WildBill, sometimes a foreign matter will find its way into the spraybar, and causes many problems. Try the solution Ken has described above, and if it fixes your problem , then moisture was the enemy. If problem persists, the remove the needle valve, and also remove the spraybar fron the engine. Using your fuel pump, connect it to the inside end of the spraybar and give a short burst of fuel through the bar. This then should flush out any matter that has collected in the bar. Refit the bar to the engine and replace the needle. Do this at home in a clean enviroment , less chance of adding more particles into the system. Remember when fitting the spraybar to the engine , the venture in the bar should be facing down into the carby body. Hope you get your problem fixed and continue to enjoy many happy hours of flying
Bill

oops a spelling mistake on my part , venture should read venturie
Bill

The PTS engine's needles will "walk" with the vibration of the engine, throwing off all of the adjustments.

Even though you may have it perfectly tuned, the "walking" of the needles (both high and low) will cause it to misbehave.

Assume that the engine is completely out of tune and have someone help you with it.

If they do, make sure that they are aware of the limters. To move beyond the limiters they must NOT force the needles, but rather release the retaining cap screw on the limiter itself, adjust then retighten.

Take the opportunity to remove the high speed needle altogether then bend the ratchet clip so that it applies more pressure, preventing the needle from "walking" in flight.

Tighten the low speed limiter while pushing it in against the engine to produce a bit more resistance.

Once you have the engine tuned, lock the low speed in place using a wire-tie or other mechanism.

Just to let everyone know moisture in the fuel was the problem. Thanks Ken. Good info from everyone. I do plan on giving it a good flush and make sure it is tuned. finally had a good day at the field. The tiger engine in the arrow ran as good as every. But after flying my p-51 its right gear collapsed on the first landing so back to the hanger for some A/R work. I tell you there is more in fixing and maintaning these thing's than flying, but I guess that is the nature of the beast. Thanks for the inputs.

I had problems with the gear blocks on my P-51, they are just not glued in very well, sadly the only way to fix them is to cut a hole in the sheeting and then try to match covering ect.. to try to make the repair look halfway decent.
Godd luck.

Has anyone else had problems with their gear collapsing on the p-51 pts? Sounds like this might be a weak point for a supposed trainer with us new guys. Because you know the landings are not always the smoothest.

Re-enforcing the gear blocks is one of the suggested modifications in the long PTS thread.

It is easy to do, and only requires applying a bit of epoxy...

Then there is also the aileron servo mounting blocks as well that normally require attention...

Check out the other VERY LONG thread.

I've been trying to find that repair in the hanger 9 p-51 thread. That is a lot of reading. Does anyone know how to do the repair on the landing gear? My right gear swivels forward and back in the socket. I have already cut back some of the coating and after looking at it don't know where to go from there and do the repair without messing it up.