KZ 750B mystery project

Greetings all,
I bought my first KZ750b (1976) this summer (2014). The previous owner stripped the bike, did some gross chopping, welding and then sold it off for a reasonable price. Excess parts included. As it's my first KZ and second bike over all I figures I might as well keep all of my questions in one place. I appreciate all comments and guidance as I move forward on this project.

Most of the work will be cosmetic. Planning to add a hoop tail end in place of the horrible cross bar that was poorly welded on, and build a new seat. The previous owner mounted an old sportster seat. It's not big enough for two and really cramps your balls. I also am not a fan of the bulbous tank. If anyone has suggestions on alternatives please share.

The engine, despite needing some tuning is in great shape. There is a slight clutch problem I am working out.

Anyway, thanks for taking a look and we'll see where I go with this thing. I had thoughts, and pressure from friends, to hardtail it....

Welcome to the forum. Looks like you have a good base for a project. That tank paint looks mint! IMHO that tank is one of the defining visual features of the 750 twin, with the hard line at the bottom of the tank.
To hard-tail or not to hard-tail... I have never seen the allure of going rigid because it makes the bike handle like crap and is uncomfortable on long rides. However I know a lot of people like the look, so really it comes down to if you value form or function more. Have you ever ridden a rigid? My two cents is this; get the bike running and road worthy, ride the crap out of it, and then decide if you want to hard-tail it. The only people I know who have hard-tailed bikes also have other bikes that are not. the hard-tails get ridden the least.

Congrats. Like all of them. Just needs a little TLC.

Welcome in! You're in with a great crew now.

As 'chops' go, that's not really all that bad. Lots to work with, and not so far gone that it can't be recovered. Looks like they were going for what's now called 'bratstyle', like a cafe crossed with a dual-sport. Not my cuppa. :whistle:

I have a hardtailed bike, and I can vouch for what Doc said. The look is great, but the ride is not so much, especially now that I've moved to a place that's 4 miles or more down dirt roads no matter which way you go out. Not a comfortable ride at all, and let me tell you about carbs leaking, sticking floats, and parts falling off... :dry:

The thing to remember about hardtails/rigids, you're making the front end do all the work. When the front wheel hits a bump, the front end comes UP. When the rear wheel hits the bump, since it's rigid it imparts all that force into the frame, forcing the front end DOWN. On a bumpy road, the effect can be somewhat akin to a bucking horse. Add silly things like apehangers to the mix, and you're in for a world of hurt. Needless to say, I don't recommend it! :lol:

Add my two cents to Doc's: Get it running, and ride the pants off it as is while you do your homework- research is cheap, fixing foolish mistakes is expensive!

If you plan on actually RIDING the thing making it a hard tail is a stupid idea. :sick: If you just plan to profile with it to try to impress folks and maybe take some selfies to send to friends who don't know squat about motorcycles go ahead and make it a hard tail. They won't know how badly that ruins the bike's handling, braking, comfort, and resale value. :laugh: :laugh: :laugh: Ed

Thanks for all of the comments! Especially regarding the rigid idea. That's definitely something for way down the road. If it even happens. I have ridden a few of my friends rigid builds. They are fun but definitely not something i want to do long rides on. I have a small sized Honda (CB200) I am currently rebuilding the top end of. It was salvaged from a stair well in San Francisco and needs a lot of love. It's great for getting around town but not much for longer rides and getting up a mountain.

My brother picked up an XS650 and is currently going down the scrambler route. We spend a lot of time in the mountains around Oregon and Washington so having something to get me up to and around fire trails would be nice.

it makes the most sense to keep things simple, hassle free and fun. The bike is pretty much already there. Aside from fabbing up a new seat and putting a loop on the tail end, the bike is great. If you look close at the photos the tail was chopped off by the previous owner. It looks gross and the welding was bad. Plus the Brake light mount scrapes the tire if you hit a bump. Anyway, easy fixes.

Please keep those comments coming. I welcome all of your opinions and comments. If you have any pointers, tips, or suggestions for me, I am all ears.

Is that a skate board for a seat? Now that's a hard tail. :woohoo: Sounds like you have the right idea. I rode a 25 mile fire road to the nearest store once a week while at Hole in the hills. 9% turn back grade getting in or out, deer running past then crossing in front of me, mud holes, glad I had suspension, wouldn't have made it back on the first ride.
Steve

Hope everyone is well. I have a wiring question maybe someone can helpe me with. I am looking at redoing my wiring harness. The PO did a pretty bad job with mix matched wire colors, poor grounds, soldering, and all. The bike is slimmed down to the basics. A killswitch at the controls, reg/rec, fuse box, alt. stator, battery and ignition oh and head and tail lights, duh. No signals no dummy lights no speedo or tack. It's pretty naked. :blush:

So my question, who has done a basic wiring job, similar to mine, that would maybe share their diagram with me? I always get flip-flopped with these simple things. ha.

I apprecite the help.

Thanks

Hi everyone, I am having an issue with this KZ. I fried the reg/rec and battery due to new guy mistakes when welding. I got a new reg/rec until from oregonmotorcycleparts and a battery from the getting place here in town. The PO did some shoty wiring with poor grounds and spiced wires so I made a new harness with an ignition switch addition and a new headlight. The previous light only had one wire in.

Since the rewire and parts upgrades I have not been able to turn the bike over. Not even a bip. I ran through the basic adjustments. Set my point gaps, checked valve gaps, used a simple bulb and wire rig to set the ignition timing and did a full carb cleaning. Compression is to FSM spec.

I thought my wiring was wrong so I check for continuity to the coil and condenser, they are live. Tail light and headlight turn on and off with the inline switch. It's a pretty basic harness.

So what did I miss? Any advice or things to consider are greatly appreciated.

I can supply photos if needed.

Thanks y'all.

Are you getting spark at the plugs when you turn the bike over? I'd start there and work your way back.

Oops, sorry I spaced in updating this thread. I got the bike up and running. Yahoo! I had a few issues. I had a bad capacitor, fried reg/Rec, bunk battery and lastly a bad ground at the tail light. That last one took the most time figuring out. Ended up gutting the light and putting in a whole new bulb housing and soldering a new ground wire.

At this time I'm riding the bike. It's a lot of fun. There is an oil leak at the base of the valve case or so it seems. I plan on pulling the engine and replacing the gaskets. At the same time I think I might start chopping into the frame. I'm not that short but I would still like a lower more relaxed sitting position and plan to lower the seat posts. Check out the attached photoshopped image of what I'm aiming for. I want to keep the comfort of the soft tail but win the aesthetic of a handtail. If anyone has done this and have some troubleshooting tips that would be rad. I already anticipate an issue with relocating the brake cylinder.

Also I'm currently swapping tanks for a sportster tank I painted for an art show. Fabbing up a mounting bracket for that too. The triple backbone is cool but awkward to work around. Anyway I'll try to keep up on this thread as I move forward.