I know this is off topic, but I should explain some things.
I have owned Quickdraws (26 and 35cc), an M&D cast cylinder engine, and lots of Zenoahs starting with a Hanson G23 in 1997. The only engine other than Zenoahs that I would recommend to average racers is the M&D cast cylinder engine. I don't have enough racing experience with it yet, but it seems very reliable, and is the second most powerful engine we have tested. It has all the modifications usually done to Zenoah cylinders built in with the addition of an inner wall to the transfers. This gives better flow direction. It has .010 squish but similar head volume to the Zenoah. It could be easily modified for higher port timing, but it would probably become more difficult to run. We have tested several other commercially available 26cc gas engines and none equals the quality, reliability, and power of the Zenoah. We do not have experience with the Sikk (Chung Yang) engines.
I hope that a G1 rigger finally sets an over 100 mph record this year. One time, one way, is not an official record. Jeff Michaud was the first gas boat over 100 mph one way, but Mike Bontoft is the only over 100 mph record holder in the world with gas engines. He holds the GX1 and GX2 records of over 100 mph. His Gas Sport Hydro has gone over 100 mph several times, but bad weather ended running before he got an over 100 record with it. We have a friendly rivalry with Jeff. He has helped us with props for several record attempts. It was a big disappointment that he couldn't quite get two back to back runs over 100. We have always run GX engines so we weren't really competing as equals. We have a friendly bet on who can get the G1 record over 100 mph.
Lohring Miller