I just checked and HobbyKing actually has some parts for some of the ASP engines in their store and in stock too. That is pretty neat. Here in the USA no one is selling parts for them. For ages it seems, HobbyKing had a Parts category, but never had any parts in it. I think JustEngines in the UK had parts for some ASP engines too. The HobbyKing prices for the parts is surprisingly low too. But shipping might be a problem in some cases.
I am not that much of a snob, From ASP; I have a AP .06, three, AP 09's, a couple of 12's, a couple of AP .15's, two or three ASP 15's, a .25, a .28, two .36's, a .46, two .52's, three .61's and a 1.08, plus a couple of the .61 four strokes too. Of the engines I have run, they have worked Ok, but I did see some problems with some of them though, mainly the needle valve assembly was allowing the needle to move around a lot and cause false needle settings.
The AP .06 the carb mounting screws would come loose on it, the muffler tip rotates as the engine is running, it ran better without muffler pressure than it did with it.
The .28 and the .36 engines both ran good right out of the box no problems encountered. I sort of like the .36 engines as they run as good as the .40 engines do but are in a .25 size crankcase.
The .61 two stroke engine ran great too, I don't remember any problems with running it. I ran one to see how it worked, but not the other two.
The ASP .61 4 stroke engines both ran well, but they both had problems with the needle valve assembly allowing for false needle settings. Plus the two 4 stroke engines did not like running less than 15% nitromethane fuel either. The valve guides seemed to be a tiny bit loose and allowed it to suck some oil at idle speed.
Years ago I had a ASP 1.08 engine and it needed a better carb on it. But the bearing cage came apart in the air and it destroyed the engine. At the time there were no parts to be found. I have a new 1.08 engine, but I haven't run it yet.
ASP .61 two stroke, 11x7 Zinger prop and 5% nitro glow fuel
The AP .06 engine needed some work, the muffler tip is loose, the carb screws would come loose and fall out, and the carb needle adjustments is more coarse. I couldn't lean it out with muffler pressure properly. But without muffler pressure it ran really good then.
ASP .36 engine (aka Generic no brand label), 10x6 prop 5% nitro-glow fuel:
ASP .28 (aka Generic no name brand):
Here is a vid of one of the ASP FS61 four stroke engines when I ran it.