I bought a couple of used OS .25 LA-S engines last year from a couple of different guys for one of my projects.  I finally got around to getting them ready to mount last night.  Both are the blue bodied engines.  Since I didn't want to use the remote needle valves, I had bought two of the stock OS needle assemblies to replace the nozzles in the venturi.  The first one went in without any problems.  The second one, though...  When I pulled the nozzle out I found that the spraybar hole had been drilled out oversized.  *SIGH*  Pulling the venturi out and measuring it showed that it was a 7mm venturi.  So much for using the spraybar I bought. So now what?  I guessed I'd have to buy a new spraybar to fill out the hole in the engine body and take up the extra room in the venturi.  Another delay on a project that's already been delayed quite a few months.

But, wait a minute!  A couple of years ago I was at a swap meet and at one very messy table with all kinds of R/C and drone stuff a guy was selling a couple of Novel .061 CL engines N.I.B. for $20.00 each.  I snapped them up.  In another junk box was what looked like a locking CL spraybar and needle.  I asked him what engine it was from.  He had no idea what engine it was from, or even what it was because he had gotten it in a box of engine stuff he himself had bought at a swap meet sometime before.  Since he had no idea what it was for, he said, "It's yours.  Take it."  So I did, and threw it in a box when I got home.  Hmmm.  Maybe it'll work.  So I spent about an hour digging through boxes until I found it. 

Eureka!  It fits!  Now to figure out if the .25 LA-S will run decently with it in the 7mm venturi.  I don't need contest performance, as I'm still a beginner.  But it'd be nice if it will give me a consistent run for three minutes.  I didn't take any pictures of it before installation, but it looks like a brass assembly with two spacers on the barrel, a threaded end with two slits 180 degree apart cut through the threads, a cap to tighten down on the threads and lock the needle, and a needle with a bend on the end.  Here's a picture of it mounted.




Anyone have any ideas on what assembly this is?  Suggestions for starting turns open?  Anything in particular I should know?

Thanks,
Mark

Oh, just saw. The venturi is .275 on yours? That's a little big. I'd still run it.  So run an 8 or 9 inch prop to keep the RPM up to get a great fuel draw.

Well, I finally got around to running this engine today, as I want to take it out to fly tomorrow.  After replacing a bad glow plug, I played around with initial needle settings and got this thing to start up.  After a little tweaking, I am very satisfied with this.  Much finer control than the stock O.S. needle valve I was going to use.  I was afraid that it would be too wide for the venturi, but it seems fine.  I set it by my tach for 11K initially.  Seems to run efficiently with the APC 10x4 prop I have on the engine.  We'll see how it works tomorrow at the field.

Mark