Funny Funny: Post 36, then a jump to post 37 about 7+ years. And it keeps moving. NEAT! I was always a Super Tiger fan until Great "Pains" took them over. Still most are excellent. I hear they are going to be deleted from the menu. While the .60s have always been good, IMO the .75 is superior. I have never had a dependable ST .90 and I have worked with them a very good amount of time. When GP took over ST, they left the small restrictor out of the carb. used for all .40 through .51. Sad business move. The carb needed that restrictor. I made them for guys that wanted such and they all ranted about how a ST .40-45-46 became a fair-headed machine.The .51 could get by without the restrictor. Never could "unner-stan" why GP just refused to stick them back in the package.
As for the GMS and such engines, they did have some problems. They were very much over-compressed. Grab a coke-can, cut a couple head gaskets, put them in their place and they changed a considerable amount for normal flying. Use of low nitro, and a 3-5% of oil mix (castor) also helped the normal sport flying. Racing models could do without the extra oil, however the fun-scale, etc. fliers sorely needed a reduction in compression, and more oil than 18%. I think I have a couple out there in the barn, still in box.
If I now wanted something new, it would be the new line of Evolution gas burners. Have to use a tad bigger engine, but the larger engine provides some extra nose weight (HA!) and much better reliability.

Now passes the next seven years, maybe we will take this subject up again.