I have got my bearings ordered today for my saito 180, I ordered the double rubber sealed for the front and a stainless for the rear.
This engine is blowing fuel out the front like nobody's business and its being thrown back by the prop blast. Im thinking but not sure (W8YE , chime in if you want to comment), that this leakage would have an effect of an air leak when the engine is running? I bought it used, and Ive run appx a gallon of 30% thru it- its on a Skyshark christen eagle, and it was turning a apc 16x8 at 9800 rpms. The last couple times Ive taken it out to the field, I havent been able to get a good tune on it, it is surging up and down at high speed, I changed the pushrod seals and covers last weekend hoping that would cure the fuel leak. Nope, still leaks like a sieve. I flew it this past Saturday in the gale force winds, so the bearings are about the only thing left to change

( I would hope so anyway, lol)
Anyway, Paul at rc-bearings has the best price going for our engines needs, in my opinion. A set of quality bearings SHIPPED for less than $20.00, come on now, beat that !
Thanks,
John