So bit of money and parts later, I'm trying to reassemble my blown up 1985 NQ50. In the teardown I looked at the reed block and noted a couple of tiny chips out of it (one on the lower face which is probably fine, but one is under the reed mating surface), and one reed not sitting 100% perfect, so I figured I'd get a new one. Problem: Honda dealer says the reed block is a no-longer-available part. I blew a whole five bucks and bought one from eBay, and it has the same bolt pattern, but turns out it has bigger valve holes in it:
(see bigger) My original one is on the left, the eBay special on the right.I'm thinking, "no, not the same size holes, so not appropriate". Given that I'm new and a complete amateur at this I figured I'd check with you folks first to be sure.
This 1985 NQ50 has an AF05E stamped engine, and it's a Canada model, I think.
My little tale:
This is the fellow that went "BANG" as I was driving and then would turn but wouldn't start. Compression only 75psi, had gas, had spark. Gave up and started taking things apart. Circlip was off the piston and rammed into the piston/ring. Cylinder was scored, etc. You can see these wonderful pictures of destruction in the flickr set. There's probably a whole host of things actually wrong given it's questionable service history, but that was the obvious bit.
The opinion of the guy at the Honda dealer (and others) was that it looks like someone tried to mod the engine a bit - sideports on the cylinder looked like someone had tried to widen them out, as compared to a new cylinder. It was also too big to bore/hone at this point, according to the spec. Couldn't get the oversize piston anyway.
So I said to heck with it and ended up buying (new from Honda) a cylinder, piston, rings, bearing, pin, circlips, and gaskets (both head and reed block). I took off the carburetor and cleaned the crap out of that. Cleaned up the head. Haven't verified the bystarter yet. I'm now in the stages of getting the engine put back together, just need to pick up the reed block gaskets from Honda and I can start compression testing again.
I can try it with the old reed block just to see if things start up again, at least. Either I'll get this working again, or it'll go horribly wrong like lots of things I do and I'll push it out to the end of the driveway with a sign that says "FREE" on it.
