RC-CAKES

My Feedback: (4)

ALL.. I just bought an old Royal Models Stuka with a ST G90 mounted. The limited history is that the plane has never flown (not quite finished) and the engine ran a few times. Not sure how old the G90 is or what it came off of.

Engine.. Italy made G90. Clean and ok shape. This is my first ST. Right off the bat I see the threads for the exhaust stud is broken off of the case. Didn't come with an exhaust/muffler. Handpropping it - seems tight but with compression. My first impression is it is too tight and maybe a bearing issue?! Now I am not forcing it to turn, but its not as easy to spin as my OS .40/.46s and Saito 72 / 125s . I am very hesiative to start the engine fearing to damage it further...

Since the case is broken already - how hard is it to breakdown and transfer to new case? Will a new case even work with an older engine? Special tools? Any other tests to perform? A new one cost $170 ish. Better to just get a new or different engine?

Thanks for your input.

RC-CAKES

My Feedback: (4)

Update: I used my after-run oil all inside the exhaust and plug hole. After some careful turning it has really loosened up. Still dragging a little on the shaft some. It seems no matter what I will need a new case from the broken threads.

Are the new ones (towerhobbies,,etc) from China? Will they work on this italian made one? Bearings..etc.

Bax

My Feedback: (11)

Current parts for SuperTigre engines are the Chinese-made parts. However, they are identical to the Italian-made parts. A new crankcase should do the job. Replacement is easy. You just to heat the case to slide out the liner and bearings.

If you turn the engine over and it tends to drag at one point of the rotation, it's possible that the connecting rod is bent. This can be easily determined once you disassemble the engine.

RC-CAKES

My Feedback: (4)

Update: I ordered a new case for the G90, along with new bearings from RC bearings. Tore down the old engine. Used this great youtube video as a guide.. awesome! Had trouble getting the connecting rod off the crank.. as the wrist pin had crud on it and wouldn't let the piston slide enough. Finally got it out. Used the oven and everything was torn down. The engine had ZERO carbon on the head;piston; chamber. It looked like it had minimal time on it. The bearings were noisey and notchy (the small one for sure).

Heated up the new case.. installed the nose bearing. Oiled up and installed the rear bearing and crank; piston; and heated up for sleeve. MANY thanks to w8ye for his assistance -especially in aligning the ring/pin. All back together and well lubed... ready for running. I wish I had the stock muffler to test with - but I have nothing so far. I plan to find a inverted pitts so that it will fit better in the cowl.

Stay tuned for test results..