Hey All,
ok, I eventually got one of these, and I have set the timing as retarded as it can go, looks to be around 32 Deg BTDC. Its not idling below 2300rpm or thereabouts. I have it mounted on a trainer that I use for running in engines, as its easy to fly, has big wheels on it so landing 'off piste' is not a problem.
When I got it, the first thing I did was set the timing, oiled up the rockers and the cam cear/lobes and noticed there were NO gaps in the valve clearance. Set it at 0.1mm...Anyway, after 2 flights, I opened up the rocker cover to check the valve clearances, and noticed the inlet has a HUGE gap from when I originally set it....opened up a LOT. I know engines need time to bed in, but this seems excessive... I also noticed that the entire valve/rocker assembly can move left/right! The bolt holding it on is tight, but there is still movement. Is this normal? I pulled out one of the pushrods and noticed there is some 'burring' on the end that goes into the guide....I sanded that down...also, after first flights, the rocker area is quite dry, the engine is mounted inverted, so should be getting lube..
For break in, I ran a tank of gas through it on the ground, using 20:1 Stihl HP mix...on an 18x8 prop. I did one of the flights with that prop, but its not enough pitch, so I have put a 18x10 on it, which is better, had more forward speed.
Not giving up on it yet, but I am a little unimpressed with this engine, but given that it cost less than half of a Saito FG40, am prepared to forgive it until I know its run in a bit...
Will keep flying it in this config, and will check gaps on valves and inspect in general....hopefully it improves...