SC61 2 stroke advice

[Bob Skidmore]

Hi folks,

I purchased some second-hand planes a couple of years ago and I am just getting round to sorting them out. I have started on a Piper cub which has an SC61 mounted inverted. There have been drips of gloop issuing from the silencer for quite a while.

I have completely stripped the engine, removed the piston, completely stripped the carb (every last screw) and washed the whole lot in thinners. Then, using my dremmel and felt polishing pads I polished the piston top and sides to a high shine and also the barrel of the carb.

My questions are:

1). having done all the above, am I right in thinking I will need to run it in again?

2). If the answer to 1 is yes, does anyone know the correct technique for running this particular engine in?

3). I have no idea how to "set-up" I/C engines in general or this one in particular, could anyone offer specific advice regarding my engine?

4) as this engine is "pre-owned" and I have no idea of its history, also the only SC website I can find is written in Chinese, would anyone be kind enough to scan in the owner’s manual for the SC61 and e-mail a copy to me please, even if it is just the relevant parts relating to running in, setting up and general operating procedures.Thanks in advance, all advice gratefully received

[simon barr]

Hello Bob,

The gloop is just that, old oil residue finding its way out. You should not need to run the motor in again as the parts are already bedded together, but if you are worried, just run it slightly rich for the first couple of flights.

When you say you have no idea how to set up the motor, how much do you know......or is it totally none at all?

[Bob Skidmore]

Hi Simon,

thanks for your reply. Regard setting up a motor, I have absolutely no idea at all. The last time I got anywhere near a R/C plane and ic engine was28yrs ago and even then it was only for a couple of ill-fated flights using an Irvine 40 engine. So in truth, I know absolutely nothing.

[simon barr]

OK.

On the carb there are 2 needles, one obvious one sticking out and another on the other side of the carb inset into the spray bar assembly. The big one is called the needle valve which is a tap to limit the fuel supply and the small inset one is to tune the idle and pick-up.

To start the engine, close the main needle valve completely and then open it 2 1/2 turns. This will be about right for the engine to start but will be a bit on the rich side. Start the engine with the throttle just above idle. Once the engine is running, start to close the main needle and open the throttle until the engine note starts to pick up. The engine will peak out at fully open throttle. If you close the needle too much, the engine will start to die as it starts to run lean, so open it a little again.

Now, close the throttle to idle and note how it runs. As you open the throttle smoothly, the engine should pick up smoothly. If it burbles, it is too rich on the smaller needle, if the engine dies, it is too lean on the smaller needle.

If it is too rich, close the small needle about 1/4 turn (clock-wise) and try again and continue until the engine opens smoothly. If it is too lean, open the small needle 1/4 turn and try again etc.

PHEW, I think that's it, but if I have forgotten anything I'm sure someone will point it out. Give it a try and let us know how you get on.

[Bob Skidmore]

Many thanks Simon, that's very helpful and in language I can understand

I'll give it a go asap (need fuel first) and report back here when it's done.

Thanks again, I appreciate the trouble you have gone to to help me.

Kind Regards

Bob

[Steve Hargreaves - Moderator]

Hi Bob...I use ASP engines & am very happy with them.....they are basically the same as the SC range (rumoured to come from the same factory even). I can email you a pdf of the ASP instructions, written by the late Paul Landels (so they are in proper English not Chinglish!!!) if you like......PM me with your email address & I'll send you a copy. The Just Engines website is a good place for engine knowledge here

[simon barr]

Hi Bob, your'e welcome.  You should take Steve's offer aswell, regardless of the make of engine,the set-up is basiclly the same.

Good luck

[Bob Skidmore]

Simon, Thanks again and will do.

 Steve, that's a great offer and I would be most obliged. Check your PM for my e-mail.

Cheers guys, you have been most helpful.

Kind Regards
Bob

[Steve Hargreaves - Moderator]

No problem Bob......no sign of a message from you though........