Hi all.

I just bought a new OS .46AX engine to power my Somethin Extra kit I'm building, and also got a Pitts muffler so I can make a cowl to cover everything up nicely.

My question is, should I break the motor in with the factory supplied exhaust, or would it be a better idea to use the Pitts muffler, seeing as thats what will reside on the engine.

Or does it even matter which I use??

My first .46AX I broke in on the plane and she is a little ripper, but I was intending on breakin this one in on the bench.
Are break ins still highly advisable for engines, or is it a bit of an old wives tale??

Cheers
Sean

G'day Sean,
Stick it in the plane, put a APC 11x6 on it, with your Bisson muffler, follow the instructions that came with it, to the letter, & you will have a great engine.
Also use 10% nitro, coolpower oil, at 18%, & an OS #8 glow plug, the 46AX comes with a A3 plug, keep it as a spare, it's heat range is too hot for that fuel I mentioned.
Forget Castor oil, that's old technology.

Sean,


Just follow [link=http://www.rcuniverse.com/forum/m_1850473/anchor/tm.htm#1850473]this RCU thread[/link] for a good break-in procedure.

The OS manual neither tells you to use castor oil and a lot of it (the [link=http://osengines.com/faq/product-faq.html#q2]OS Q&A[/link] does); nor does it tell you to run it at a proper setting (a bit too rich for my taste).

The worse is that it doesn't even differentiate between ABN and ringed engines...

Break in is still necessary, and it's much easier to do it on the bench. I'd use the stock muffler. When the engine is broken in, then change mufflers and retune it.

This is an ABC/N engine and should be broken in only SLIGHTLY rich in a two-stroke setting. Due to the piston/cylinder fit at the top, it needs to get up to operating temperature to properly break in.

Dr.1

It is an ABN engine, and Castor should be used. Even Morgan fuels does not recommend Cool Power for these types of motors. I would suggest Omega, and live with a little goo on the plane. The pitss will help keep most of it off the bottom to begin with.

The AX is a very good engine, you could probably get away without breaking it in on the bench, but its a simple process and worth doing. Personally, I'd break it in with the muffler you intend to use on the plane (the pitts), but using the stock muffler won't hurt anything.

Thanks for your replies guys, muchly appreciated.

Cheers
Sean

That's right, daven, fuel with a castor/synthetic mix should be used in ABC/N engines.

dr.1

Got mine about a year ago, out of the box noticed very little pinch at the top, but great compression, ran about 3 tanks of 10% wildcat fuel and put on the davis diesel head, easy flip start, great throttlle response up and down, Its going into a Pulse XT40 on its side with a pitts type muffler ,will look nice that way not sticking up and the cowl works out well that way
martin