'75 KZ400 Break it Loose!

Hello! First post here, and I'm hitting the ground running with a build thread!
Daily rider is an 81 GS550T that I've had a few years, so I'm familiar enough with what it takes to get these old ladies up and running. However, I had been looking for a project that I could really sink my teeth into, and learn the ins and outs of these old bikes.
I picked up this bike in the condition shown in the photos for $200, with boxes of the original parts.
My plan is to do a slow-burn winter project to keep me busy through the cold winter here in Milwaukee.
I'm an architect/designer by day and a custom airbrush artist by night, with really no metal fabrication skills, so we'll see where that lands me with this bike!
I'm posting in the Specials forum because I really don't have a genre pinned down. My goals for myself are to gain a deeper understanding of the bike, and to gain simple metal fabrication skills.
For the bike, I'm putting an emphasis on minimal controls,design based on reliability, and something that I can jam through logging roads on the weekends. Mostly Desert Sled, a little tracker, a little scrambler, and a little resto.
80% commuter, 20% scrambler, but I want to bring that "backwoods" attitude to the city.
Photos as I bought her:

Table built, bike carried into basement (that was a treat).

And here we go! The bike came with all new gaskets, and mentioned that the bike leaked, so without knowing where exactly, I'm replacing them all. I'm not planning on splitting the cases, though I probably should, and I have the gasket sitting on my bench (advice?).

Engine is out of the bike. Cleaning up with simple green and a wire brush. Debating on whether to paint the engine or leave it lie. It's in such nice shape that I'd almost hate to take away from that.

And that's where we sit! I've got an airbrush project I'm finishing up the next couple of nights, then I'll be back at the bike!

That bike has independent rear suspension (good on cars / bad on bikes). :laugh: :laugh: You need to weld a piece of frame back in at the very rear to keep the 2 frame rails form going their separate ways. Ed

Splitting the cases is not a big deal, especially considering how close you are already. Doing so will give you an opportunity to peek inside, and it will insure that you have new gaskets and seals on the bottom end.

Welcome to the board and congrats on your new purchase! It looks like you got a real good deal for what you paid. I agree with Texas, splitting the cases at this point is a "might as well do it" kind of thing. By the way, If you need carburetors, send me a PM. I have 2 pairs of stock CV carbs for sale.

My project bike is a '74 KZ400 that I picked up a month or so ago. It also has the typical oil leak where the cylinder meets the crankcase on the front side. As I understand it from my research, it's because of an oil passage that makes an abrupt turn and is very hard to seal up. My bike only has 3300 miles on it, but because it obviously sat for a while and was tinkered with previously (top end was pulled off, permatex oozing out, presumably to try to fix the oil leak), I'm doing a complete engine rebuild on it with all new gaskets, seals, bearings, etc. I think of it as a good insurance policy.
Candi

650ed wrote: That bike has independent rear suspension (good on cars / bad on bikes). :laugh: :laugh: You need to weld a piece of frame back in at the very rear to keep the 2 frame rails form going their separate ways. Ed

Thanks Ed!
I know I need to tie the rear together somehow, and account for suspension travel/clearance, but I'm hoping to find an alternative to the traditional cafe "hoop". Though, I'm realizing that is just may be the best/cleanest route. I'm also planning on bringing fork tubes in from a KZ440 up front for an extra 2" in height, and getting taller shocks in the rear. Does anyone know if I can swap just the tubes/springs between the 400/440 shocks, and keep my lowers?

KZCafeChickNJ wrote: Welcome to the board and congrats on your new purchase! It looks like you got a real good deal for what you paid. I agree with Texas, splitting the cases at this point is a "might as well do it" kind of thing. By the way, If you need carburetors, send me a PM. I have 2 pairs of stock CV carbs for sale.

My project bike is a '74 KZ400 that I picked up a month or so ago. It also has the typical oil leak where the cylinder meets the crankcase on the front side. As I understand it from my research, it's because of an oil passage that makes an abrupt turn and is very hard to seal up. My bike only has 3300 miles on it, but because it obviously sat for a while and was tinkered with previously (top end was pulled off, permatex oozing out, presumably to try to fix the oil leak), I'm doing a complete engine rebuild on it with all new gaskets, seals, bearings, etc. I think of it as a good insurance policy.
Candi

Thanks! I had been following your thread. You seem to be doing everything the right way! I'm thinking more and more that I'll just pull the entire engine apart. Mostly it's a matter of overcoming my fear of splitting the cases. (uncharted territory), but hey, that's why I started this bike. To learn! And as you said, I might as well have the assurance that I have fresh seals/gaskets throughout the entire engine.

knitt31 wrote: Thanks! I had been following your thread. You seem to be doing everything the right way! I'm thinking more and more that I'll just pull the entire engine apart. Mostly it's a matter of overcoming my fear of splitting the cases. (uncharted territory), but hey, that's why I started this bike. To learn! And as you said, I might as well have the assurance that I have fresh seals/gaskets throughout the entire engine.

Thank you. I appreciate that. I know it can be scary to open up a bottom end the first time, but believe me when I tell you, when you're all done putting it back together you'll think to yourself "That was amazingly easy". If you have basic mechanical ability, the factory service manual, and document everything with photos for reference during reassembly, you'll be just fine.

SPLIT THE CASES 6, I am rebuilding a 440 for the second time because I didn't feel that splitting the cases was important...

Do yourself a favor and check out the insides.

Two bolts short of getting the cases split. Can't get them to budge! Tried heat, pb blaster over night, and good old force. The heads aren't stripped, but I can feel the shaft of the bolt twisting when I apply force, so I'm afraid to over do it and snap them off.
Any more ideas? Thinking I'll try the impact screwdriver with a 12mm socket tomorrow

Do you have access to an impact? If not your friends are heat, penetrating oil (I prefer Kroil) and time.

Soak them with Kroil for 3 days, then try again. Ed

Which bolts are causing you issues,Got a picture?

The larger bolts on either side of the bottom were giving me issues. I got one free with some heat/impact.

However, the second ended up snapping..

I've got the cases split and purchased a set of left handed bits, (two of which I've already snapped).
Seems like the bits are dulling really quickly, but I've got patience. Trying to work through this the right way.
The general consensus is to stay away from the screw extractors, correct?