Hi there

I bought a used ugly stick with a O.S. 45 on it. There are no letters on the motor Just O. S. Max on one side and then 45 on the other, behind throttle cable. I believe I need a new carb as some times when you go full throttle it quits, and no amout of adjusting will help it. On the front of the carb. it has 4BK Can I still buy that carb, or will another carb work.? Thank You for the help in advance.

G'day Mate,
Try a new OS #8 glow plug, & try again, if problem persists, also clean out the carby, & fuel tank, change fuel lines, & make sure the engine is not gummed up with castor oil residue, or varnish.
A new carby will not fix your problem.

FZeller,


From the [link=http://www.osengines.com/parts/discontinued.html#carb]#4BK carburettor[/link], your engine is probably the OS.45FSR (unless this carburettor was fitted onto a different OS engine...). See photo from the OS TimeLine below.

This engine is one of the best ever made by OS and is much better than its newer siblings, its replacement, the .45SF and the later .46FX and .46AX.

This engine will also last longer, uses the same bearings (front R-6Z, rear 6902) and if it is the ringed version, Frank Bowman will supply a new ring, if you ever need one. If this is the ABN vesion, ABC parts from equivalent Sanye engines (Magnum, ASP,...) may suit as replacements.

Alan is right about recommending the #8 glow-plug, but you can also use any other long reach 'warm', or 'medium' rated plug, like the Novarossi C-6S, the Enya #4, the Rossi R4, the K&B-1L, or even the OS #8 clone trom Tower, the TowerPower plug.

Up date on engine problem, First of all, I'd like to thank you guys for your help. Now heres what I did. I took the carb off, and cleaned it. I put it back together, put in a new O.S. number 8 plug. and I still have the same problem. It starts good, it has a good transition to half throttlel, it idles well. It will even run wide open for a short period of time and than it slows down and quits. Tomorrow I will put a new tank on the outside of the plane and hook it up to the carb and try it. If anyone has an idea what the problem might be please let me know and I will try it. Thanks again for your help. Will let you know what happens. Fred

G'day Fred,
sounds lean, richen HS needle 1/4 turn & try again.

We did it, We did it.!!!!!!!!!!!!! I just hooked up another tank on the side of the plane. Put new fuel lines on it, hooked it to the carb and she ran like a scalded dog. Now all I have to do is take out the old tank and install a new one with new lines and I am in high cotton.
Life is good. !!! thanks again, gotta go. Fred