O.S. Max 20 reconditioned

GallopingGhostler wrote:Really good work, sosam117, looks like new. You really turned it around.

Seems to be some inflation on the engines on E-Bay, when I last looked, prices are up, but occasionally see some disguised blessings.

I don't have anything in that size from OS, but have the Max .15R/C that I bought NOS may be 6 or 7 years ago, and an NOS Enya .19-V venturi C/L version, both with mufflers. With some gentle tapping straightened a low time Enya .19-VI TV that had a bent prop shaft.

Anyway, good save.

Funny thing.
I had an OS Max 10 I sold on R/C Group (Jan. 2020), just because getting parts for it was getting tough.
I may use it to swap for an Enya engine?

I purchsed a Max .15 a while back. It was cheap enough and was a local engine, so postage cost was low. It was described as a good low-use engine with good compression. I was suspicious due to the pictures (ebay) which showed no glow plug, 2-3 head screws missing and the backplate was installed in reverse. But it did still have its NVA and muffler. Hard to believe that they knew what compression actually was. I ordered a set of original OS socket head screws, but I discovered that when I pulled the head down tight I had a really tight spot as the engine was turned over. After close examination and lapping the piston to the sleeve, it still had the tight spot. Then, I noticed that as the piston moved up & down it rotated slightly. I dismantled it completely and found that the rod had a slight "woof" in it, which easily straightened. Still the same problem. I then noticed that the crank pin was bent at the web. Examination showed that it was actually cracked, so the crank was only fit for the bin. After quite a bit of searching and patience I found a replacement crank from a Polish seller. Price was reasonable enough to go ahead, although my bargain engine had now become far more "normal". (I rarely pay "normal" price for an engine)

So, the upshot is, once the crank was installed I could confirm that the problem had gone away and the engine had good "genuine" compression. It takes a little starting, but it runs really well. I'd still prefer my Enya .15 over it any day, although I still believe it's a far better quality engine than many other popular brands out there. I do think the Japanese have better quality control than anywhere else in the world.

Engine looks good , wish you had the before pics. that just makes it even better . I have i think 3 of the 20FP, Ken kept talking about how good they are and i couldn't remember if i had purchased one and they just kept coming up SOoo No cleaning on any of them needed .

You've done a great job, Looks like new. I have a OS Max 19. Allmost as big. It's one of te steel cylinder series from the beginning of the 60's. The crankshaft thread is #12-32 and I can't find a coupling for it. I contacted Dumas by mail but their couplings for similar size engines have different threads nowadays. What crankshaft thread has yours?



Here is a video. I think they start very well

https://www.youtube.com/watch?v=279yfgzv9a4

OVERLORD wrote:You've done a great job, Looks like new. I have a OS Max 19. Almost as big. It's one of the steel cylinder series from the beginning of the 60's. The crankshaft thread is #12-32 and I can't find a coupling for it. I contacted Dumas by mail but their couplings for similar size engines have different threads nowadays. What crankshaft thread has yours?



Here is a video. I think they start very well

https://www.youtube.com/watch?v=279yfgzv9a4

I check my crankshaft threads on my OS Max 20 and it is #12-24
This engine I think was made in the 1970's?