I've owned a Aviaster, the carb is similar to Tower, Chinese random quality control. I sent in the Aviaster, SIG replaced it. Then I had a good engine, but sold it not really seeing the advertised power anyway. OS has the best carbs in the business, and costs a premium.
The Thunder Tiger Pro 46 is a balance between price and quality you won't regret. You might find a used OS or second hand new one, and achieve the OS quality for the TT Pro price.

You brought up A good point about the SK line, I have gotten bit once or twice going for that needel valve. Never drawn blood but I have come home with A red knuckle. When Ed Moorman tested the SK 90 I just had to try one, that sold me on SK. I have had great luck with the PRO series and never had A problem with an OS, even the LA series.
Now then, anyone want to buy some MDS engines cheap????? OK, just fishing!!

n19ht: Can you post a picture of the bottom for your covering job (or post it here:
[link=http://www.rcuniverse.com/forum/m_7799636/tm.htm]http://www.rcuniverse.com/forum/m_7799636/tm.htm[/link]

Graybeard: At risk of getting way off topic, I notice in all your posts you use a cap "A" (vs "a") in middle of the sentence...any reason?

I put the 55/4* in the air this am. 11x5 APC, 12800 ready to fly. Really changed how it flies. Vertical forever!! Fast! Flew it the same way I have been. The manuevors just took a lot more sky. For those that say it is too much, can you ever have enough of a good thing? It certainly doesn't need more. This is just a break in plane for me. The engine will be going on a profile edge. The 4* will be getting the other Saito 45 for fine tuning.

My other planes get my heart pumping, a mellow 4* is fun without needing total concentration.

SO WMB, you suggest a 46 then?

A 46 will work great.