Steve I admittedly don't know squat about that engine or brand

BUT the only front rotary engines that run clockwise are either well flooded or have a left hand crank installed

Many Mfg used to provide a lefty crank for a variety of reasons...twin engine set up, torque roll in to out, pusher
 configuration...I have a few Cox TeeDee with left hand cranks

Running backwards is fairly common for agressively-timed two-strokes -- they make the intake open early to give the air more time to get going into the case, but that also gives the air more time to get in there while running backwards.

Like Motorman said -- does it run better clockwise or counter-clockwise?  If it's unhappy going backwards then the engine is designed to be a screamer.

I was only able to get one short lower power run going counter clockwise (looking at the front of the engine), it runs best rotating in the opposite direction of what most engines run. It starts easiest without the muffler and it ran best using 5% nitro 29% castor compared to a 10% nitro and synthetic blend. It has such good compression my electric starter would not turn it over and eventually I broke the nylon prop using a cheater stick. I was not able to get it to start rotating it clockwise only counterclockwise but when I spun it would crack back and start while hitting the stick this is what broke the prop. It did this in both a lean and rich setting.  It will rev very high and appears to be very strong using a 10 x 6 prop.  So it's made in China, has anyone any experience with helicopter engines? What if I use a pusher prop on it? I noted when it runs in reverse the fuel is sucked out of the venture going thru fuel much faster than normal, what ever is normal here?? Is there a helicopter site I can challenge? I'd like to use it, it is relatively light compared to my EVO 36 while having the same power, but much more than a Fox 35.

Steve

"CS" engines have always been "variable" in quality. It could well be that the crank port was not machined properly, or maybe the helicopter installation required LH rotation. CS engines are known to sometimes have ball races loose in the case, or loose on the crankshaft, and other serious buffoonery. The engine in your picture looks a lot like another PRC product, the LEO engine. Muffler rather resembles the ASP/Magnum units. The NV assy. looks to be a genuine Super Tigre unit, but the venturi doesn't look like any I've seen before...tho a nice enough bit of machining.  If the venturi bore is around .275", it should run ok on suck if there's no leaky backplate problems.  Steve 

I bought a CS .15 CL engine a dozen or so years ago.  Externally they look decent.  This one had a long venturi and an anodized red cylinder head.  Fit was pretty poor and finish of the piston looks crude.  Hard to start and when it did, had no power whatsoever.  It improved a tad after 4 runs but it'll be used as a paperweight.

Any number of Carrier guys have installed a "left hand" crank and used pusher props to advantage. Fox made the left hand crank available for the Combat series, and others have had special cranks made. Using a left hand crank has helped the slow portion of the Carrier flights. perhaps you have just such a crank in your engine. I had a left hand crank in a TD and it preformed very well in Mouse 11 some years ago along with a left hand prop I made, copying one of the old KK left hand props.
Joe

Check the port timing. You don't need a degree wheel for a rough check. The attached timing diagram shows a Fox Stunt motor on the left. The graphic assumes you are looking at the front of the engine. You can see that the crank port on a right hand timed engine begins to open after the rotation passes Bottom Dead Center and the piston is on the up stroke. So, take out the glow plug and remove the muffler. Turn the engine over slowly counterclockwise and look down the venturi. The shaft port should open just a bit after the piston begins the upstroke. If that is not the case then you may have a reverse timed engine.

Over priming and high compression also might be contributing to kick back starting.