1976 Z400 Project

Thanks GPzGuy, but I did one a few months ago for a trials bike and I found it a good process, but patience seems to be the key skill. Ben

I set myself the target of getting the carbs off the bike. It would be some good luck if I was able to clean these and then with some spark get the Z400 fired up before I actually tackled anything to do with the aesthetics of the machine. First issue encountered was getting them to separate from the throttle cable. After finding another pair of hands, it turned out the springs on the throttle cable pulley had ceased, so after cleaning, I was able to get the cables apart. In all, I suppose this is a saving as I thought the throttle cable would need replacing as it wasn't able to twist.

Inside the carbs it is a mess. The fuel has turned to treacle and seized the engine exit of the carb on the right side (secondary operated). It is starting to free, but only with force. It is in such poor condition that the jets that should fall out are stuck within their chambers. I have used carb cleaner, and maybe with some more cleaning they will free. Later in the week I will tackle the left carb which looks more complicated and try and get them in some working order with the idea of trying to get it started next weekend.

Thanks for reading! Ben

Those are pretty messed up. In the U.S., I think we still had the piston-slide cv carbs on the 1976 Kz400's. I like those much better than the rubber diaphragm carbs. Is it possible that bike was a 1977 model manufactured in 1976? I'm not aware of the European variations.

Possibly Loudhvx, or possibly I have got the wrong year!

We have come up with a good cleaning in paraffin, but at the moment it looks like a couple of days in meths might de-gunk them where things start to move.

The weather in the UK is bad so being stuck at home I decided to do some research on the Z400 and discovered a treat. Without the V5 I wasn't sure which year this bike was but after some looking it turns out it was first registered in May 1978, meaning that the carb is in the latter section of the Haynes manual and explains why it didn't look like the diagram I was previously working from. Could this also mean that the oil leak may have been corrected already?

In dismantling the carbs, there is a rubber blanking plub over the pilot jet. As this bike was last taxed in 1984, the rubber has perished and split during removal. Does anyone know how important this bung is and whether it can be replaced as an individual item? Ben

you need the rubber plug for the pilot system to work OK.

You can find the plugs on Ebay, but they are heavily overpriced. I need 8 of these as of right now, if you search my 75kz400 project or the 76 one, you can get some info on that thread.

I've had some luck finding these relatively obscure parts on eBay searching for the OEM part number. Sometimes you can get lucky buying NOS from someone who has not researched each item number and is just looking to unload something.

Lots of cleaning over the last few days and the carburation system has come together nicely. I have managed to save the rubber bung (just) on the left carb, but the right one broke so temporarily i have reinserted the small section, but will be on the hunt for two more. I was surprised about how well it now seems to moving after what`i thought might be a serious throttle issue; I'm starting to realise no job is as simple as it first appears, but stick with things.

The next step for me is to get a battery and fuel into the system and see if I can get some spark and therefore ignition. While this is going on, I did find a trick to brighten up the chrome work by rubbing it down with tin foil. I have tried it on a couple of innocuous spot and it looks better although not perfect.

hi Ben
ill have a look in my junk pile as im sure ive seen some rubber bungs like the ones you need for the carbs
regards

Whether or not the starting of the bike goes well this weekend, the front disc brake needs a serious coat of looking at. Has anyone used a master cylinder rebuild kit from the internet and can recommend a good supplier (preferably in the UK)? I would ideally like to use a modern braided front brake line, but it is an money spent on a part should the best restoration value come from an original part. Do people have an opinion? Ben

Didn’t have a problem on wether to bobber mine or keep it standard as it came as a bag of bits with parts missing and what was there was just about shot anyway , just not worth the time and money to restore , but at least the thing had a v5c which is a plus .
Yours looks to have been built when Kawasaki was altering stuff on the z400 model, you seem to have an earlier engine and frame with the later carbs , the exhausts look later too and a few other bits . I’d keep it standard price on the up in the uk for standard machine.