Been meaning to start a project thread for awhile now, so here goes the novel...
Two summers ago I got a big pile of late model F parts. frame/swingarm, wheels, 2 engines (both stuck) triple tree and a box of brackets, lights, etc. Had no real use for them, thought I might build some kind of single seater using a factory F tail, but wasn't in a hurry.
I've collected miscellaneous 750 parts for years, but I kept my eye out for late model F stuff, and started squirreling things away to use someday.
This past spring, I smoked a shift fork in my K3, and lost 2nd gear. The K3 needs restored (didn't know it then), all its major service operations had been put off by previous owners. So here I was, looking at two 'dead' bikes, needing to get a ride going.
First thing I found was a "running" engine. K5, "15 thousand miles" but no bike or odometer to confirm. However, the valve train looked good, cam lobes seemed to be on track with "lower mileage" so I bought it for 100 bucks. Seemed like an easy R&R to get my K3 operational while I rebuild the engine. When I got the engine out of it though, it was obvious that it needed to come completely apart for new bearings, bushings, etc.
So I started looking around at the parts stash, and realized I was actually pretty close to having the F2 together, if I used the K5 engine.
Here's what I started with as "pretty close" haha.
I did have the whole front end at this point. That header is an RC, made for DOHC. I'm still in the process of fitting it, but I think it can be done. (More on that later) At this point, I've already installed new taper bearings in the neck, and I've regreased the swingarm. The tank is an F0, I had a new OEM petcock for it already, but I had to de-rust and seal it. I used Red-kote, easy peasy, came out nice. Had a big dent in the top that I don't have a picture of, but a dent buddy of mine got it most of the way out. Certainly better than what I started with.
Turns out, the K5 needed a re-fresh. It's never easy, is it? It needed the valves cleaned mostly, but the cylinders were glazed as well, so I did a top-end refresh with honda parts. After honing, the cylinders were still in spec (at the far side, but that should be ok) so I cleaned the pistons, replaced 2 galled piston pins (rod ends are ok) and put it back together. On the head, I cleaned and decarboned everything, and then lapped all the valves, and did some of the hondaman mods- blending the intake snouts a bit mostly, but I did de-shroud the valves as well. I had a bunch of pics of the engine rebuild, but they appear to have been lost. I also put new o-rings in the oil pump, and checked the primary chains and tensioner. Here's the engine as I got it, after I degreased it.
So while I was fanagling the engine rebuild, I started putting the frame together to mock things up. This started the process of "what am I going to do with this pig?"
I decided that I was going to build a rider. I am an all season rider when I have a bike to ride, so I decided to build this as a gentleman's express so to speak. Not really too much on the express since it's still 736, but no matter. It's really just a ragged street burner, but I'm building this to ride everyday, in the rain or whatever. A bike I can ride all the time and not care about keeping all the sh*t shiny on it. Mechanically sound, just not too pretty. I plan on running a full windjammer on it in the cold/wet until I can find a Vesco I can afford.
So I bought some Avon AM26 road riders for the comstars, and got the frame rolling.
I hated the seat right away. So I found a different one in my stash that needs a cover, and I put a set of empty cases (with an output shaft and sprocket) in the bike, and did the first mockup of the header to see if it was even close.
It's actually going to work with a modified bracket, and some clearancing on the head. Not as low as I imagined it being.
So any astute readers will say "K engine in a F, chain problems." Yup. I did a thread on this already, but here's where I started for alignment.
Kind of hard to tell, but once you see the front sprocket you can very obviously tell that the engine sprocket is inboard of the rear sprocket.
The difference in chain line can be corrected with an early carrier- the two side by side- clean is the 77-8 one.
More to it than just changing the carrier though, once you change the carrier, you have to figure out the spacers for the sprocket side. There was some debate about this in my thread, but if you leave the brake side alone, you do not change the wheel alignment. The late model spacer is 7mm longer than the early one, so you have to cut a spacer. So I cut down the late model spacer to the correct dimension, and got my chain to line up.
I changed phones in the middle of this project, and lost some pics. But after the chain issue was sorted, it was time to get the re-freshed engine in the frame. I didn't bother painting the engine, maybe I will if I ever pretty this bike up. Plus at the time I was in a mad dash to get it together to ride somewhere, but my caliper pistons ended up being fooked so that plan was foiled, and by now enough time had passed and it had gotten cold, so my progress slowed.
I made re-doing the brakes more of a chore than it needed to be. I messed around with the idea of getting some of godffery's phenolic caliper pistons made for these calipers, then I discovered the twin piston calipers bolt right up with proper bracketry, so I spent some time looking for cheap sets of those, then I finally just decided to redo the single pot calipers I had, and if I ever find a set of twins, I'll just sell these. So I finally ordered 3 new steel pistons, which just came a couple days ago.
The oil tank I found was used, but looked good. Turns out it had a bunch of sludge at the bottom, which I'm still in the process of removing. On my last solvent soak right now.
One of the F engine I got donated it's rotor, which was a little lighter than the one in the K5 engine. I also did the hondaman clutch mod, but I'll make that another post.
Thanks for looking!
