1978 KZ400 B1 - Scramber to be

Looking good Dan. That is going to be a fun bike.

Did not get a lot done this weekend but I did acquire some foam for seat padding and a black leather jacket that should make a nice seat cover if it fits, it will be close. I glued the layers of foam to the seat pan last night. Hope to start shaping it this evening.

Tip: these reflectors are a good replacement for the originals on the front of the frame under the tank, they screw right in. The pattern is a little different from the stock ones but at $5 each they are (for me) a better option than the $20-30+ each I saw people asking on ebay for NOS or even used take-offs.



Chris Safety Products 2-1/2" stud mounted round amber reflector: amzn.to/2nloIvI

Seat shaping underway. I have no idea what I am doing - I'll just keep faking it until it looks right.

When I first put the layers together I put way too many layers of the base layer and the seat was much too tall. I ended up having to cut out everything but the first 2 layers - which explains why the top layer of soft white foam is cut into sections. But I think it is a mistake I can overcome. They should all glue back together well enough. This is much closer to the profile I am looking for. After nearly two hours of shaping it is getting close but still probably a couple more hours to go - it will be perfectly smooth (or pretty close) when I am done.



Test fit of seat cover. It is not pulled tight, just on loosely to make sure it would fit. It should look less like a big black brick once the cover is stretched tight and fastened down... hopefully. If not then I'll take the cover back off and continue shaping until it looks good.

After test fitting the cover I found a couple of soft spots in the padding that need additional foam added. And I'll need to add a more foam at the front where the seat meets the tank so it does not drop off so drastically.

A couple of weeks ago I started thinking that the euro-style handle bars that I am using are too low and do not have enough sweep at the ends for the style of bike I am going for. I tried to set those doubts aside but it has been eating at me every time I see a pic or look at the bike. I think it really needs a set of vintage looking MX/desert style bars. And I'm thinking of going chrome with them instead of black. I've fought that doubt as much as I can and I've given in - I just ordered a set of vintage looking bars that should be perfect. They have a 5" rise and 5" sweep versus the 2-3" rise and sweep the current bars have and they also have a crossbar. Unfortunately that means that I will probably need to order a new stainless brake line - I don't think the current one will be long enough, I'll have to wait and see. But on a more positive note the stock throttle and clutch cable lengths should work well with the new bars so I will not have to order them in custom lengths.



I'll be able to switch the black euro-style bar that is currently on it to my 76 KZ400 to replace the chrome superbike bar that is on it now. Additionally if I do need to buy a new brake line then I'll also use the current one on the 76 to replace the original rubber hoses. I'll just switch from the stock brake splitter/switch to a banjo bolt with a brake switch.

New handle bars on. The brake line was just long enough to move over the additional inch or so. This looks much better, more balanced, a little more vintage looking and provides a much more comfortable riding position with no leaning forward at all. I'm not a huge fan of chrome, prefer black when I have the option, but this bike does not have a lot of chrome on it so I think these bars look good and fit in.







After seeing the middle pic above I'm a little bothered by the way the brake line hangs down. I may change from the 35 degree banjo bolt that is currently on there to a 90 so the the line runs more along the handlebars and then down the forks. I'll wait until after I have the throttle cable in place before I make a decision.

I also worked on shaping the seat padding some more. I think it is right now. I started stretching the leather cover on and I think it will work well.

Next up: finish fitting the seat cover, get the seat hardware mounted again and get the seat mounted. Finish up the mounting brackets for the speedo and tach. I also have a vintage Kawasaki crossbar pad in the mail that should look great.

NOS crossbar pad that is rather old came in and is now in place. Seat cover is installed - it is not great but it does not look bad so it will do for now. I need to stick to the budget and I still have carbs to buy and an exhaust to fabricate - once those are done I may revist the seat and have it done professionally..

Pulled it out into the sun this weekend while I was cleaning up the shop a bit.







While it was out I took the tank off, washed it up, polished it out a bit and added some wax. It still has 40 year old patina but it's nice and shiny in spots now! Pushing it back into the shop I got a pic of it sitting beside it's 2 year older brother.



While digging through the parts boxes I found that the old clutch cable was still in good shape. So I went ahead and got that mounted too. I also took a look at the tach and speedo cables. The tach cable is broken but the speedo cable is in decent shape even though the ends have a little surface rust. I'll clean up the ends and paint them and get the speedo cable mounted up soon too.

Next up: adjust clutch cable per FSM. Clean up and mount old speedo cable. Buy carbs and new throttle cable. Buy new tach cable. Buy side panel graphics.

diggerdanh wrote: NOS crossbar pad that is rather old came in and is now in place. Seat cover is installed - it is not great but it does not look bad so it will do for now. I need to stick to the budget and I still have carbs to buy and an exhaust to fabricate - once those are done I may revist the seat and have it done professionally..

I've been watching this build and it reminds me of the dual-purpose/enduro bike I rode in high school.

I got a seat cover from a place called The Vintage Spoke. It might be a little more streetbike-looking than you would want but it fit well.

What are you planning to do, carb-wise? I was going to make all kinds of changes to my 400 but now I just want to ride. This means there's a pair of NIB VM30s and a new throttle cable sitting here unused...

Nerdy wrote: I've been watching this build and it reminds me of the dual-purpose/enduro bike I rode in high school.

Nerdy wrote:
Perfect! That is exactly what I'm going for. If Kawasaki had made an enduro/scrambler type bike on the KZ400 and I still had the one that I had ridden in high school and it was mostly unchanged since that time this is what it would look like.

I'm planning on buying a pair of VM28s to use for the carbs. I have a pair of VM30s on my 76 KZ400 and they work well. But like you I just want to ride it and I'm so close. Over the last couple of days I've been looking at the VM30s on the 76 and thinking I should just pop those off and onto the new one - then I could take my time ordering the other carbs. But if I do that in the short term I'll have 2 non-running bikes and if a nice day pops up I may kick myself that I do not have anything to ride.

diggerdanh wrote: Perfect! That is exactly what I'm going for. If Kawasaki had made an enduro/scrambler type bike on the KZ400 and I still had the one that I had ridden in high school and it was mostly unchanged since that time this is what it would look like.

I'm planning on buying a pair of VM28s to use for the carbs. I have a pair of VM30s on my 76 KZ400 and they work well. But like you I just want to ride it and I'm so close. Over the last couple of days I've been looking at the VM30s on the 76 and thinking I should just pop those off and onto the new one - then I could take my time ordering the other carbs. But if I do that in the short term I'll have 2 non-running bikes and if a nice day pops up I may kick myself that I do not have anything to ride.

I hear ya. Maybe you can swap the VM30s over very quickly and minimize the downtime.

Are those IRC Trials GP-1 tires? Or maybe GP-110s? I had those on the high school bike as well. :laugh:

Nerdy wrote: Are those IRC Trials GP-1 tires? Or maybe GP-110s? I had those on the high school bike as well. :laugh:

They are Shinko 244 Dual Sport tires.

IRC Triais GP-1:


Shinko 244


Look pretty close to me!

How did those tires work for you on your High school enduro? The Shinkos are said to be a pretty good 50/50 on-road/off-road tire. I suspect my usage will be more like 60/40 but I have plenty of room and trails to ride around my house so I'd like them to work well when I do go off-road.

diggerdanh wrote: Look pretty close to me!

Wow, they are really close - practically identical in the tread department. I wonder how the rubber compounds compare.

I recall the IRC tires being pretty decent. I did about 50-50 on/off-road at the time and they worked well just about everywhere. They would tend to pack up in mud and they weren't good in the snow but that's probably not their fault.

The high school bike was only a 250 so it didn't tax the tires too much.