Custom GPZ550 (ZX550A and KZ550H)

japstar

Been Around the Block
Hi there,

Some key things about me:
-Belgian fella
-Student engineering, but heart for hand work.
-Started out with restoring old Honda Camino
-Than Honda cb50
-Honda cb two fifty as daily ride, but hoping to change that with this project

This project has been going on for a while now, but only recently decided to start a project page on a decent forum.
I started off with buying two bikes. The ZX550A on the right for the engine (more power and no mechanical advance and better front fork), the KZ550 on the left for the cooler looking rear end and fuel tank.
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Next up was stripping the frame of the KZ550 from redundant mounting points and backstructure.
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Upon disassembling the front fork of the ZX550, it seemed teh stanchions were shot, so I needed to look for a new front fork. The fork of the KZ550 had an offset for the wheel axle, and i didn't want that.
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As for the adjustments on the frame, I bended a hoop to weld on the rear end. I've cut out the sidewalls of the tank and brazed newly fitted knee dents in there. Originally, the tank had a bad shape, causing a discontinuïty with the seat. That was the first reasing to start grinding away on the fuel tank :)
I also straightened the frame (where the saddle will be mounted), because the stock frame had a kind of valley in the frame, not ideal for the straight seat I was aiming for.
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I wanted a slightly bigger swingarm angele, so i modified the linkage dogbone to make ik longer. I made a I-profile like the stock dogbone, grinded the stock dogbone in two and welded the piece between it.
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Accoring to kawasaki, the rear shock wasn't serviveable. But I didn't find that word in my dictionary so i added a valve to service the shocks.
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I also found another front fork of a suzuki GS550, for dual disc brake. I also like the older look.
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Modified the forks to lower them without the need to raise them in the clamps.
Also brazed on of the two rebound holes shut to get some more rebound control.
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Concerning the electrical stuff:
I made my own hadlebar switch:
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Also the self made dashboard with switches and speedometer.
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I fitted all the components before making the tray:
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And with tray frabricated:
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With the start push button at the bottom:
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Mounted the rear light (led light with brakelight included)
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Also modified the stock ignition key to my likings:
stock on the right and custom on the left:
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With mounting bracket:
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Mounted in the dashboard:
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And there we go:
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canyoncarver said:
Interesting project. Looks like the rear wheel has a clearance problem?
At certain angles it may seem that way yes :)
But it has 11- 13 cm left. And I added a higher bump stop to the rearr shock, so wheel travel shouldn't be a problem :)
I haven't had a problem during test riding so far :p
 
Cleaning the carbs:
Made my own soda blaster to take off the stock paint. (Carbs are made to be raw aluminium in my head :) )
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And they turned out well:
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For the brakes: I had to remodel the brake pedal to avoid damaging the exhaust (Marshall deeptone, was on the bike when i bought it)
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The brake pistons were all pitted with rust, so i made new ones out of Stainless Steel on the lathe.
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Because of the new front frork, the mounting plates for the front brakes had to be adjusted:
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And the front was fitted with tailored steel braided lines.
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And i bought an old malossi throttle to fit the bike :D
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Some other stuff that happened and current state of the bike:

Previous owner did a lot of fixing with putty, so some removing and rewelding was needed. At the front (by now chopped) fender, in needed to punch out a lot and make tailored steel blanks to weld into place:
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I want my rear end to be adjustable. I want to be able to ride a full seat (bit brat style), or add a cowl, or mount a luggage rack.
So I fitted 4 mounting points in the frame, to fasten the cowl or the luggage rack. (still needed to be welded in the picture)
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The current state of the bike, I called her Patsy by now 8)
On the self fabricated paddock stand
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On a test ride:
The bike's suspension is how i like it, and it's power is very much fun :) ( I come from a honda cb two fifty with 14 kW) She pulls very smoothly, with a raw sound. And she hits 180 km/h with ease, as i had to stop than because i ran out of road.
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The colourscheme I'm aiming for: (based on interstellar's suzuki gs 550)
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This sunday, i lowered the back of the fuel tank to follow the line of teh frame more closely. But I haven't got pictures of that.
A lot of pictures will be missing from the process so far, but I've been working on it for over a year by now. (Was very busy till last year). But now that I've put it on this forum, it seems like I did nothing during that time ;D
Anyway, next updates will probably be about dismantling the whole bike, and starting to prepare it for painting.
 
Just did a small thing today before going to school. Made some small mounting pieces for the wire harness to the rear light.
Made to weld on the frame and fit a ziptie trough it. Should be clean and out of sight i think :)
Also decided to get the frame and swingarm powder coated to be a bit more resistant to rust. I will spray the rest with spray cans.
Going to remove cylinder had and cylinder for good cleaning/blasting, that gives me a chance for a quick inspection of the engine top end.
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I'll be following this. I think it's cool that you don't hesitate to modify or make things to be the way you want them. I like your handlebar switches, those came out really good. It looks like you have some cool machinery to work with too.
 
fatleon said:
I'll be following this. I think it's cool that you don't hesitate to modify or make things to be the way you want them. I like your handlebar switches, those came out really good. It looks like you have some cool machinery to work with too.
Thanks, I can't complain. Most of it are old machines of my grandfather, and my father expanded it a few years back with a lathe. Only thing I still want is a mill. Gues I'll have to sponsor some money to the expansion 8)

The handlebar switches are based on an ebay product. They were only about 20 dollars to buy, but where's the fun in buying if you can make it?

I pulled off most of the modifications to my liking, except for the gas tank. I think I tried welding it three times (each time failed, had to cut it open again and prepare new knee plates each time too). Than i tried brazing, but I grinded already too much on the tank, that the walls became too thin and that made it impossible to even braze them, kept on having small leaks.
Decided to use tank cure, and it holds up for now :)
As soon as I encounter a new gas tank for a decent price, I'll cut it open again to try again, to have a fuel tank without filler and tank cure :) Or maybe I should learn how to use the english wheel in time? ;D
 
Started disassembling her:
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And made a temporary spray booth, oven included. Anyone have an idea as at wich temperature I should bake painted parts and for how long?
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VonYinzer said:
You shouldn't bake painted parts. Only powder coat or special high temp coatings.
Well, I wouldn't really bake them, just put them at 60°c for faster curing. I don't want to wait 1 month to ride the girl :)
And I've heard that letting them cure at 60°c should lower the chance for orange-like surface? (The fruit, not the color :p )

Anyway:
Today I made a new dashboard (had a bad day, had to start over 4 times or so). The first version had an inclination with respect to the top triple. The new one has the same angle as the top triple. Resulting in a more compact front view of the motorcycle, because amongst other things, now I can move the front light closer to the dashboard, leaving less open space.
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And some chill company whilest working:
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Inferred heat and low humidity will help paint, depending on type, cure faster and harder.

http://www.bodyshopbusiness.com/cured-let-s-talk-about-why-the-paint-shop-runs-slower-than-the-metal-shop/
 
Removed all covers from the engine for painting, removed cylinder, cylinder head en valve cover for bead blasting and painting.
The engine case itself is still snug in the factory paint, so I'll leave it like that. At least until the complete rebuild of the engine after some years.
Cleaned up the casings and pistons and whatnot.
BTW: there was a strange head gasket, it were just three aluminium gaskets on top of each other, while when you buy a gasket kit, you get the normal type of head gasket. Anyone that can explain this?

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Got no pictures of the prepared frame and swingarm, but they are delivered to the powder coater.
Also some tools arrived today, wheel balancing stand and valve spring compressor. :)

I'm going to try to spray most of my parts with the spray gun with 2 component paint for durability.
I couldn't trust the spray can paint for the wheels etc.
Still got some satin black from a few years back, never opened, and gonna order the color for the wheels.
I'l spray the tank with spray cans, but with 2 component lacquer.
For the engine, I've found some good paint (buddy of mine his father restores old motorcycles ('30s -50's) and uses it for all his projects). Just gotta spray it, bake it in the oven as specified.
The site is french, but no problem for me, cause the geographical bottom half of my country speaks french and france is my neighbour. Maybe you can find the paint in the US to? http://restom.net/moteur-pont-boite-de-vitesse/239-restom-blackcylinder-pht-2020-1224779386.html

And does anyone know where i can find oversize pistons for my engine? And which prices do they go?
 

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japstar said:
Removed all covers from the engine for painting, removed cylinder, cylinder head en valve cover for bead blasting and painting.
The engine case itself is still snug in the factory paint, so I'll leave it like that. At least until the complete rebuild of the engine after some years.
Cleaned up the casings and pistons and whatnot.
BTW: there was a strange head gasket, it were just three aluminium gaskets on top of each other, while when you buy a gasket kit, you get the normal type of head gasket. Anyone that can explain this?

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The head gasket question. When you put it back together with the new gasket, make damn sure your pistons don't hit the valves. It's possible somebody has had this engine open before and changed something. If the head was shaved/decked, they might have had to increase the gasket thickness to compensate.
 
canyoncarver said:
The head gasket question. When you put it back together with the new gasket, make damn sure your pistons don't hit the valves. It's possible somebody has had this engine open before and changed something. If the head was shaved/decked, they might have had to increase the gasket thickness to compensate.
Good tip, the head gasket was strange anyway. It were 3 aluminium gaskets on top of eacht other, while original parts lists only show 1 gasket (the paper one with aluminium rings around cylinders). Didn't throw them away, because they seemed handy if I should add some squish.
Just test it by turning the flywheel i gues?
 
So I started painting and preparing all the parts.
I'm gonna paint with 2K with the spray gun, only tank with spray can white and 2K lacquer from spray can.
Cleaned up the old spray gun from my grandpa, quite the chore, it was covered in some thick 15 year old paint. But with the help of a acetone bath and the soda blaster it turned out very nice.
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Masked and painted the wheels with primer. (Primer is spray can)
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