1979 KZ400 B Restoration/Recommission

Thanks for rescuing another KZ400 from the crusher. You are doing great work. 
Surprising how few KZ400s you see. I was at Barber this weekend and saw just about every make and model of motorcycle, but not a single KZ400. 

Thanks all, nice to know I'm on the right track!

Nerdy, yes forgot to mention I got new rim strips as well! I was trying to be fairly concise with my catch up posts and missed that off haha. That is a great suggestion for the seat, unfortunately I threw the old one away quite some time ago as it was leaving rust flakes and bits of old foam wherever I put it Now that I'm likely not going to ride the bike until Spring, I'll probably have a look for a decent replacement cover and just re-cover the thing.

Skidmark, ah I know of the Galfer name from my past life working in Brakes engineering for an OEM, I didn't appreciate they do more than just pads, I'll look into that.

ThatGPzGuy, yes they really don't seem to be very common, I'm not sure how many Z400's got sold here in the UK but certainly you see plenty more Hondas still about than the Z's. I went to a pretty big show a couple months ago and did see one Z400 project for sale which was a surprise to see!

Little update of my progress over the past month or so. I got finished fixing the wiring to the ignition switch that someone had cut previously, so that's now back mounted loosely on the bike. I've also disassembled the kickstart lever as it was coated in old dirt and oil grime so that'll get a nice clean up, the rubber is a little loose on it as well so might change that but will see.

The big progress is that I got hold of a second hand head without the cam journal bearing damage that my original head has. So I got both heads dropped off to my local engine shop for them to make me one good head out of two.

The good news is that I have a cleaned up, assembled head with valves fitted and new seals



The bad news is that the camshaft that came with the 2nd head is in poor condition, it's got some pretty bad cam lobe wear like my original



There are some more camshafts on ebay, but as with all used parts, it's a bit of a gamble. So either I go for 3rd time lucky, or I find a cam place and see if they can have a go at regrinding what I've got. Haven't got much to lose on the second option!

Aside from that, I've now got a big pile of engine casings that need blasting, so I'll be getting that sorted ASAP and I can get to reassembling the bottom end at least

Been a while since I've been on to update this thread but I've mostly been slowly collecting the various bits I need to put the bike back together. A couple of big breakthroughs for the engine build were finding some bearing shells which should work and a NOS camshaft which was proving to be a big sticking point!

I did send off the engine casings for vapour blasting which cleaned them up nicely, I've been spending a lot of time washing and re-washing everything to make sure there's no left over media from the blasting



More recently I've sanded and polished up the side casings, went through a few grades of wet and dry paper followed by hand polishing, not going for a mirror finish, just a nice maintainable look. I re-painted the infill for the letters on the covers as well and thought they came out pretty well







Managed to get a replacement tank as the original is quite rusted out. It's a B1 tank rather than a B2 but they're nigh on the same and I prefer the more retro badging anyway. Will get repainted along with the side and tail covers at some point



There are a few bits to sort on the rolling frame still but I'm mostly focused on the engine build at the moment

Looking good.

Great work Adam, come a long way in a relatively short time. 

Nice work and thanks for the thorough documentation.   

Scotty

Great following project!

Thanks all! Been a bit slow going as other projects have taken some of my time (and money) as well but trying to keep the KZ going. More recently I've been focusing on getting the engine back together, so I've been continuing to clean up bits that I'd taken off a while ago.

The good news is that the starter clutch assembly seems to be in good condition so was just a clean and reassemble job, similar story with the balancer weight assembly so that's good to go as well.

Unfortunately one of the pistons is looking well past it's best



There are grooves that I can definitely feel, the other piston looks fine and would go again. Being a '79 it seems the specific type of piston used was only used for a short period of time before the 440 replaced it. Which is annoying as the one replacement piston I can see in Europe is in Italy and costs a fair bit, but there are plenty of earlier type pistons available in the UK for less, typical

Next job is to get the crankcases and crank out to my local machine shop as I want to get the oilway plugs out to be sure there's no sludge hiding in there and I trust them more than myself to not mess it up!

Well done, I am following a similar process to your self.

Cheers

Thank you, got quite behind on updates on this, been making slow progress with the engine build but have been forging ahead with it more in the last few weeks. Just seems to be a lot of waiting around for parts to arrive!

Since my last update, I did end up buying a NOS replacement for my damaged piston, wasn't cheap but needs must



I made a decision to paint the engine parts that wouldn't be polished, so made a start on hitting the bits with some vht silver. These had all been vapour blasted previously so after a good clean, the surface was ready to go



Otherwise I was cleaning up the various bits to go back in the crankcases like the kickstarter shaft assembly etc. While I had the upper crankcase out, I trial fit the starter motor I bought previously and found that the original one I bought wasn't right



No mountings for the cover that goes on top. Somewhat luckily, when I bought this starter it arrived with one of the lugs broken off, the seller apologised and sent me a replacement which was slightly different in design. This turned out to be the starter I need

I'd taken the crankcases and the crankshaft to a local engine shop to have the oilway plugs removed and I gave the oilways a thorough clean out. My main concern was the cases really where there was still a fair bit of grittty residue from the vapour blasting, but I got them nice and spotless.

With everything clean, I checked bearing clearances with some plastigauge and it all came out fine





Made a start on reassembly of the crankcases, very satisfying putting clean parts back together considering the state it was in when I stripped it down



Selected the best cam followers out of the spares I had and reassembled the rocker cover along with new seals for the tacho drive



Oil filter got fitted along with a cleaned out gauze filter, and I have fitted a new magnetic drain plug as well as new oilway plugs