desaulhpat

I recently bought a used OS 10 from a shop. I don't know much about these engines as I am a beginner in the sport. The problem is, the owner of the shop is not of a great help. First he told me that the engine was new ( the previous owner never finished his project and got discouraged). There is a clicking noise coming from the connecting rod where it connects to the piston axel especially after I disassembled and cleaned the engine <font color=white style="background-color: 3E3E3E;">(is this normal?)</font ft>. The clicking noise is not so noticable after fuel has entered the carb end compression chamber. It ran prety good with the first quart of fuel he sold me.(Top Fuel 10% nitro, specially formulated for use in r/c cars and trucks. On the bottle ,It said not to use with airplane engines). I was also using a glow plug os#3 with the 10% nitro. Last week, I bought some more fuel but this time he sold me (Power master 15% nitro, 18% oil, synthetic/castor) and a medium hot spark plug (os # 8). I thought small engines needed hotter glow plugs? Since that, the engine is very hard to start.(I use a stick or my finger. No starter)It starts on a bench but it needs a lot of force to start. It runs pretty good after it has started. On my aircraft ( miniature hang glider) I am restricted with space on top of the propeller, It makes it harder to turn the propeller. The fuel tank's tube is at the same level as the needle, fuel is entering the carb no problem but there is also a leak around the needle ( only one mixture needle and one iddle needle). I tried a richer or leaner mixture with no success.
What is the problem? or I should say the problems. Please somebody help me!

Claude.

ballgunner

My Feedback: (1)

I have never owned an OS engine that was not an FX that didn't have what you call a clicking sound when the piston is at TDC and the prop is rocked back and forth. I sent a .61 back to the factory after it started leaking oil through the front bushing and the "clicking sound" seemed abnormal. I received a brand new engine as a replacement, no charge. Guess what, same sound and same leak. If you have a leak around the needle you got trouble. Sometimes there is a very small "O" ring that may have disappeared or gotten lost during the cleaning process. It is there to prevent the leak. I'll bet the needle is fairly loose as well. As to your choice of glow plugs just look at the manual that should have come with the "brand new" engine. Check with the other pilots at your field and see what they use. I no longer have a .10 around but the .20 and .25 manuals recommend a #8 plug. If there is another hobby shop not too far away try there for more reliable information.

downunder

The clicking sound is quite normal with an ABC engine. Because of the tapered bore the piston can't quite go as far up the liner as it should because it gets wedged in. This puts a strain on the conrod bushes and as you turn it a little more all this strain gets released and you hear the click.

desaulhpat

Ok. I know what the problem is. I put the engine back on the bench and it started no problem. The reason is that I have more space on top of the engine to yank the hell out of it. I am so restricted with space when it's installed on the hang glider. The needle is leaking a bit but it seems to work fine anyway. Would an electric starter recommanded with such a small engine?

Thank you all for your replies.

Claude.

ballgunner

My Feedback: (1)

Norvel, which I believe is now distributed by Sig, has a very fine small engine starter for about $39. For years I flipped Cox engines by hand. Not any more. This little machine seems to be very well built and you'll wonder how you ever got along without it. It will spin your OS like a button on a privy door.

desaulhpat

<blockquote>Quote
<hr>Originally posted by: ballgunner
Norvel, which I believe is now distributed by Sig, has a very fine small engine starter for about $39. For years I flipped Cox engines by hand. Not any more. This little machine seems to be very well built and you'll wonder how you ever got along without it. It will spin your OS like a button on a privy door.<hr></blockquote>

<font color=white style="background-color: 3E3E3E;">Thanks for the reply. I'll check it out.</font ft>