Scubaozy, as I mentioned in my post, I am going on personal experience. I never suggested that my experience should be construed as advice. I was merely putting the issue in a context of MY experience. If its advice on whether to buy them for his project or not, I would probably say no. This is not a result of the cracking cylinder issue, it simply because I don't think this engine (or its bigger and smaller siblings) have been through enough R&D. There are MANY concepts about this engine, that I believe are potential failure points. This includes the problems experienced by the larger FG84 that was brought out without things like an efficient induction system, lack of bush/bearing on the main crank and insufficient lubrication allowances on the upper valve train on Cyl 1.These are basically 3 glow engine designs, converted to gasoline, bolted to a common crank and case. Its not ideal. Also, lubrication of the crankcase is reliant on ONLY what blow by the piston...using 2-stroke oils that are designed to burn off as much as possible in the combustion process, is not going to leave enough to get to the extremities, running a richer mix is going to help, but will also result in more fouling of the plugs. There are many things wrong with these engines in my opinion and there even discussions on the validity of the timing. Only Saito would know better, and they have just released the FG90 as a replacement for the dud FG84.....with lots of new mods etc.
My engine was as dry as a bone when I got it, so I put raw oil into the crankcase to get things lubed up before running it. Only a little bit went in, probably 25ml but I shudder to think how much damage could have been done with nothing in there. The bolts holding MY cylinder down, were tightened after the first run in tank, and much like the 2nd hand one I bought, required (IMHO) excessive tightening.
People, if you think my findings are pure BS, by all means make your own decisions.
My engine is currently in a cheap Yak-55 airframe that I care very little about, it was bought for running in and is continuing to do service while I 'tinker' with this engine if I don't get some positive results, it will stay in this frame for good, and I will not be spending large sums of money to repair it when it breaks. The other engine I have, has done break in, and will sit in a box until I am confident it will gain the right fuel/oil mix, run cool enough in my summer temps, and hopefully not expel a cylinder.
Again, not ADVICE on what you or anyone else should do.....just my experience.
They sound fantastic, and there are plenty of reports by people who are running the nuts off them with no failures.....I wish I was one of them. If I got 200 flights out of this engine, in a great warbird frame, I would have called it a good 'investment'.

I really don't know of any similarly priced engine that would do what this does, so it is a shame. More alarming is that a reputable company like Saito would err like this, but that's where my blame goes to Horizon, a bunch of money grubbing suits, who have used corporate pressure to get this to market, at the expense of Saito's longstanding name in the market.

There, I said it...