Don't be too fussed about the F2/3 top end nightmares, if the bike has been well maintained that won't necessarily be an issue. I've owned two F2's, the first was a very well mainatined original 1 owner bike with around 40,000 miles on the odometer, and had no issues at all, apart from a problem with the engine misfiring horribly on a wet day, which turned out to be a faulty seal at the base of the ignition switch, after I first replaced the entire ignition assembly, coils and leads. Oh well, I took them off again and reinstalled the old parts before I sold it.
The second F2 had "God knows how many" previous owners, had been crashed, thrashed, and even had been on fire at one point, which had melted the wiring harness and a part of the air box. The engine had been "rebuilt", but the "mechanic" had left out a piston pin circlip which allowed the pin to rub up and down the cylinder, and carved a groove which was too deep to bore out. The valves rattled around in the guides and the tips of the valves were "mushroomed", a common fault with F2 valves because the tips were too soft, and the steeper F2/3 valve angles (to allow bigger inlet and exhaust valves) further exacerbated the problem. It was well and truly screwed...........
F2/3 engines, if regularly abused, not maintained and run with filthy oil are also prone to valves jamming in the guides, causing terminal engine failure. I've got two F2 heads that have come frome engines with dropped valves, and it's not a good look. I converted that engine to a K6 top end (cylinder block, head, pistons and cam) and never had any major issues after the conversion. Contrary to a previous post, the F2/3 engine was fragile compared to the K and early F series bikes, but a good one is a joy to own. Your bike looks pretty tidy, so of course if it was me I'd buy it, but I've got the wherewithall to rebuild it if necessary, for not much money. Up to you mate, but it looks like a pretty good deal to me. Cheers, Terry.
