I couldn't recall the cheap "605" kits showing up on ebay... Henry Abe kits...
They aren't 605cc even for a CB500 or a CB550 as they were 61mm at the bottom skirt and 60.5 at top if I recall correctly. They come with cheap 61mm pistons that have a poor oil ring design (1 piece that's prone to break), rings, sleeves/liners for the CB500 application (as the 500 can't be bored to 61mm safely), and gaskets. They come to a 592cc, so it is a misnomer or the like...
Their piston design has a narrow oil ring groove that is difficult to find rings for if you are reusing them, and a good 3 piece wider Honda oil ring is much preferred. The rings are known to eat themselves trashing/grenading a good motor. The torque and power is nice and coupled with a CB650 ('79-'81) SOHC camshaft makes a nice improvements on a nimble handling CB500 or CB550.
If they are the Henry Abe pistons, the machine work on the pistons to accept a stock CB750 std ring may not be worth it. Some of the Henry Abe kits have holed a piston...another nasty engine failure...not always from the piston design as a poor build.
Even the 750 pistons require some mods to work with the CB550 if I recall correctly and starting with a 750 good set of std pistons is a nice way to start a Gentleman's Express with added quench band and valve pockets for the CB550 design. The skirts are long on the Henry Abe pistons and they are marked with a HAINDST most of the time...
Here's something bwaller posted about widening the oil ring groove:
"Sorry I missed this ct. It's safe to say the rings that come with this kit are just plain junk, there have been several bad news stories.
I had an early standard size 61mm CB750 piston to compare with the Henry Abe and the top two compression ring grooves are the same, but the oil ring groove on the HA piston was narrower than the 750 item. Find a shop to widen the oil ring groove on those Abe pistons (I believe it was 0.011", and was removed from the bottom land) and you can use the excellent quality Honda rings. Just check end gaps before you assemble (although I didn't have to adjust gaps at all)."
One person reported that their pistons had "HAINDST" on the inside skirt and 600cc.
The Henry Abe pistons also feature a "They have a 23.5mm pin height, vs the 23mm for the stock 550/650 pistons"
Mohan wrote in one thread: "I believe if you read through this thread:
http://forums.sohc4.net/index.php?topic=53682.0 and look at Terry's replies 18, 25, 28, and 37 he gives details and specs for Henry Abe 592 kit pistons..."
Jerry Rxman Griffins wrote concerning the Henry Abe kits (they also did a 900 kit for 750s) and gaskets sources... "Yeah, Cometic is the way to go. Tell them you have a 900 kit in your 750 SOHC Honda. Get the base gasket while you're at it. My Henry Abe kit has tapered sleeves at the bottom ends and will fit on a stock case that hasn't been machined and should use a stock base gasket. Yours might not. The base gasket will probably depend on which sleeves you have. Talk to them about this too. "
bistromath wrote: "If this is the Henry Abe kit, I can't advise you strongly enough not to use the rings that came with the kit. Everyone on this board that's used those rings has come up with compression leaks, and there are reports of grenading engines due to the lousy 1-piece oil control ring. The remedy is to use standard CB750 rings with the 3-piece oil ring. To make it fit you have to enlarge the oil ring groove by 0.011" on a lathe."
The 750 "300" ring set is the preferred replacement with work on the H.A. pistons to enlarge the oil control ring groove and use a properly sized set of 750 "300" rings.
So, if you had a 1 piece oil ring on some of your pistons (think you said there were parts in the pan...) then they are probably Henry Abe pistons which may have been sold by ART or Henry Abe sold ART piston sets...not really clear who sold which...
Sounds like you might be lucky and this isn't a Henry Abe kit afterall but it does have ring issues if there were bits in the pan...
