Saving a 1980 750 twin.

I originally picked this bike up for a buddy, who vastly underestimated what it would cost to get this thing on the road. The PO did the usual dumb stuff, needless to say it did not run and alot of stuff needed attention. It also has no title. As as started working on it for my friend I fell in love with the looks of this engine, and when he decided it was too much of a financial obligation i bought it off him. Despite the engines external appearance it is squeaky clean inside, and when i checked the valve clearance everything was at optimal spec and it has great compression. I'm starting to think the odometer may be correct and that there is only 4500 miles on the motor. this is what i bought it as...






I know what some of you may be thinking, "Finish your damn kz1000 project first!". I am moving to california in a couple months and apparently registering a no title bike there is a nightmare, its not easy in Washington, however its pretty straight forward. So the plan is to fix what needs fixing, triage some of the stuff i want to do so I don't have to do it twice, get it inspected by the state patrol, and register it before I move so I can start the 3 year probationary period for the title.

Im getting pretty close to being ready for the inspection. I plan to use a lot of the parts that i originally intended to use on my kz1000 before that went a completely different direction. I'm gonna be doing it in a style that has been done to death; aka Go Takamine, Wrenchmonkess.... etc, i think that style suits big twins well, and id like to do some small performance mods. Also i want to do some of the stuff guys are doing on their kz1000's here like bracing the frame and beefed up motor mounts. Down the road I'd like to send my cams out to megacycle for a regrind, port and polish, and get some hot carbs.

Parts i already have slated for use are:
New engine covers - the early twin style, the PO trashed the existing with a flap wheel.
KZ650 spoked wheels - lighter than the stock mags, rear bored out to take 20mm axle.
Avon Roadriders - in the factory sizes, 3.25x18 and 4.00x18
Aluminum Works shocks - these are setup for a kz1000 so likely will need to be revalved/ different springs, they are rebuildable
GS1100E swingarm - shortened to the stock 750 length
tarrozi fork brace
kz1000 forks - rebuilt with progressive springs
KZ1000 LTD fender

I got a chinese TIG welder a couple months ago and have been welding like its a part time job to practice up. Turns out my buddy is not only a great welder he's an excellent teacher, so I have picked it up pretty quick. I'm proud to say I have done all the fabrication on this bike, except the aluminum work on the swing-arm, don't have much practice with aluminum yet.

Ill let the pics do the talking from here

Very nice work, Im loving everything about the bike so far! Sorry to hear your title issue is turning into a nightmare; here in oklahoma we just have to file for a tile and it's sent to us in the mail if the bike turns out clean. Anyways, hope everything works out for you and keep up the great work!

this is going to be a cool lil ride :evil: !

looks as tho you split some tube and plan to cap the top of the swingarm???

can't wait to follow along as you transform this one.

keep us posted,
leon

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531blackbanshee wrote:
looks as tho you split some tube and plan to cap the top of the swingarm???

Yep thats the plan Leon. Its such a weird extrusion for the factory to pick. why wouldn't they just go with a rectangle tube? I thought it would look cool boxed in but it probably wont do much for strength.

Im a little worried that its gonna end up too high in the back. the Works shocks are already 1" over which is fine, but to mod the swing-arm in a way that doesn't look weird it will end up adding another 7/8" to the height. I found an old post on here where Steell says he is running 2.25" over stock Konis on his twin with progressive forks and it rides great so i guess we shall see. Ill measure the geometry when its all together.

that is going to look good.
it is a weird extrusion, but it does add strength over not having it.
adding that split tubing over the top is going to really add a lot of strength :evil: .
romans didn't use all them arches on the aquaducts for nuthin man .

leon

Ill get some better photos of this when its done. still needs shock mounts, torque link mount, chain rub, chain guard mount, and a zerk on the pivot tube. (where were you on that Suzuki?)

oh hell yes !!!

that turned out cooler than the other side of my pillow ...




leon

Thanks Leon. Im very pleased with how its turning out. I have been reading up on how to do artificial aging with aluminum to return strength. For a precipitation heat treatment of 6061 you do 6-20 hours at 320F°. Or 6-10 hours at 350F° I know the stock gusset in between the arms is a different alloy because it reacted very differently to the NaOH. it stayed bright while the arms turned dark like 6061 does. Some alloys aren't heat treatable, so it may not make a difference. My neighbor is a chef and has a commercial oven in her house that she has agreed to let me use to bake this thing. Im going to use a rockwell gauge to see how hard it is before and after, mostly for my own curiosity.

That seat is beautiful. I want to do something like that with my XS650.

Adventures in aluminum... other than some practice beads, this is the first aluminum piece i have ever fabricated/welded myself. I am loving this welder.