OK, here is where we are: Fuel seems to be OK since it was the same container I have been using with other engines without problems, however I switched to a new gallon I had - no improvement. The #8 plug is a "short" plug with no idle bar. I do not have any short plugs that have idle bars. The #8 is what the manual recommends, but I did try a new A3. The A3 is the same length as the #8, but with a different heat range. Anyway, that did not help.

I have the engine on my test stand with an APC 12-10 prop. The engine starts very easily and responds well to needle valve adjustments at WOT, but refuses to run below about 6,000 rpms. I am turning about 10,200 with that prop. I did notice that around 6,000 air bubbles appear in the line from the pump to the carb. At higher rpms there are no bubbles. There are no bubbles in the line from the tank to the pump at all.

I had one of these engines several years ago in the Phoenix 6 that I am restoring, I just don't remember having any problems with it. Of course this is a used engine and my memory is not what it used to be! Who knows what "adjustments" have been made to this particular engine over the years. I hope no one has played with the pump adjustments, but I have no way of knowing. Unfortunately, spare parts for these old engines are not easy to find, especially when it comes to carb, pump or piston/liner sets.

I would really like to get this engine running for "old time sake".

I ordered the O-rings and we'll see if that helps.