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James' 77 550f.
luceja:
just writing some jetting info.
I'm back down to 38 pilots, screws leaned way out to 2.5, 110 mains. I was surprised it was still acting rich down low with leaned out stock pilots, but talking to mark linder (if I understood correctly) the stacks may be pulling more fuel through via friction, as opposed to just vacuum, so I'm going to try dropping the pilots and a step, but as-is, it's totally rideable and enjoyable right now - no weak spots. The only oddities are a few signs of richness down low: needs zero choke to start, a bit of stumbling/ 8 stroking at idle, sooty plugs, won't return to idle when hot without blipping the throttle. I have to note that I've changed jets since last sync, some of the idle symptoms may just be that.
I am, however, hearing a little popping out the exhaust off throttle, which would be a lean pilot symptom. Hmm.
luceja:
Also, made a new mold to lay up another seat - wasn't happy with the first one. A little short, narrow, and sloppy.
luceja:
for the folks who were interested in the seat-making, here's where I ended up:
Re-did the on frame mold for the seatpan - a little wider and longer this time, flat on top:
laying the glass - I went thicker. First layer was the weave, then lots (5?) of build layers. I also was laying strips of the weave along the rim every layer or so - I wanted it to be strong at the edges.
here's the profile of the pan:
where it meets the tank:
prepping the mounts:
Which look like this on the bottom:
this on top:
in the back they slip under my fender mount:
and in the front there is a plunger I made on the lathe (not pictured) that locks into a cable release thingy from some other bike:
did 3 layers of rebond, glued down, rough shaped with an electric knife:
And then finally, Ginger at new church upholstered it.. she's amazing:
The color is... unique. Originally I was going for brown, but two years later, I've seen plenty of bikes with the exactly seat style in brown, and thought I'd try something new. My lady was encouraging that maroon color, so that works for me. Something unique without being overly gaudy, I think. Could work into a nice paint scheme.. though with a bare tank, it looks suspiciously like this bike.. http://www.bikeexif.com/honda-cb750-4
One my my main goals was to have the seat exactly follow the tank's bottom line to emphasize what I think is the signature design cue from this generation of motorcycles.. it's hard to capture in a photograph, but there is an unbroken, curved line created by the tank and seat from front to back that is exact to the mm, and the seat conforms to and exposes the frame's line , just coming half way down the frame's top bar, exactly. The cross section of the seat conforms to the opening in the back of the tank, and the back profile angle of the seat curves down to follow a line to the fender. The length of the seat was chosen to balance the length of the tank, when viewed in profile.
The consequence to designing the seat to follow these lines that are already part of the bike is that the seat is very thin compared to the tank, which makes the bike more tracker-brat flying fist looking than I intended, but I guess that's cool right now?
Anyhow, extremely happy with the bike. I'm amazed how strong the engine is - it's a total joy, and there's still lots of crispness to get back by leaning out the pilot circuit.
There's still a list of small things to do - just polished and rebuilt the front wheel with new spokes/bearing, currently polishing and rebuilding a rear wheel with cb750 rim. Paint work, replacing the (occasionally slipping) clutch plates, etc, etc, on and on.
Also - random note - do not use jasco on plastic side covers. I may have ruined my otherwise fine side covers for this bike.
fastbroshi:
Cool, seat looks great, especially in regards to its relationship to the tank. Some brat style bikes are done with what seems to be a focus on the seat and end up looking cartoony. What colorare you thinking for the tank?
luceja:
--- Quote from: fastbroshi on June 27, 2012, 02:27:26 PM ---Cool, seat looks great, especially in regards to its relationship to the tank. Some brat style bikes are done with what seems to be a focus on the seat and end up looking cartoony. What colorare you thinking for the tank?
--- End quote ---
Thanks and agreed, and I wasn't really shooting for brat style, just a slightly slimmer dimension of the main seat, but I think I overdid it slightly and ended up at the edge of brat territory... but again I'm really happy with it, especially the quality of Ginger's upholstery.
For the tank, I'm thinking a plain solid color with a old HM decal, in white or off-white, with gloss black side covers, though I've fantasized about doing some more inspired designs on the tank.. but nothing concrete in my mind there.
I'm also brainstorming about using a spare 400f tank I have lying around. I already took a little bit off the tank mount posts on this 550 frame, so the only fitment issue is that I'd have to widen just the very front of the tank's tunnel to fit over the "A" shape of the 550 frame. It seems to be the right length tank but a better width to match the seat... just a weird idea I suppose.
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