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-   -   1975 KZ400 - Project (http://www.twtex.com/forums/showthread.php?t=107510)

freeriders98 02-01-2016 05:55 PM

1975 KZ400 - Project
 
I have been wanting to build an old cafe/tracker bike for a long time. I just refused to pay top dollar for a bucket of parts.

So long story short, a member on here had a bike in his garage and said to come grab it. So sight unseen I hooked up the trailer and got it. It was MUCH MUCH better than I was anticipating. It will need some love but, but hopefully I'll have it running soon. once I've got it running and dialed in I will start working on turning it into what i want.

Here she is
http://i208.photobucket.com/albums/b...psvs4pleri.jpg


Items that need addressing:

1) One spark plug hole was 90% stripped, could have been why it was parked. Was only able to get 90psi compression on that cylinder. That has been fixed with a Spark plug repair insert.

2) The coil and plug wires were missing. A new coil was sourced, wires purchased and put together. Still need to build a Coil mounting bracket, and hook up the coil. Will need a battery as well I am sure.

3) Need a front brake lever and master cylinder. Thinking about updating the entire system to something more modern. Need to look into it more.

4) The Carbs are my main hang up. Stock boots, fell apart taking them off. Carbs are NASTY and need rebuilt. I was dead set on switching to s ingle carb set up with a Mikuni VM34. Then went back to "I'll just clean the stock carbs to get it running" When I went to clean them, they need to be rebuilt. So do I spend the money to rebuild them or put that money towards a new single carb set-up? Open to ideas and suggestions. Here are some pictures of the carbs.

http://i208.photobucket.com/albums/b...psggsdcebe.jpg
http://i208.photobucket.com/albums/b...pswq7f7r9q.jpg
http://i208.photobucket.com/albums/b...pswq7f7r9q.jpg
http://i208.photobucket.com/albums/b...psnhr1prvt.jpg

freeriders98 02-01-2016 05:55 PM

Re: 1975 KZ400 - Project
 
This is what I would love to see it turn into!

http://i208.photobucket.com/albums/b...pswtcoirgx.jpg

http://i208.photobucket.com/albums/b...ps5ppa2heg.jpg

Keepitgreen 02-01-2016 06:33 PM

Re: 1975 KZ400 - Project
 
Nice!
Good luck!
I am always on the lookout for a kz 400 also.
Cant wait to see it finished.


Sent from my iPhone using my thumbs.

freeriders98 02-01-2016 06:54 PM

Re: 1975 KZ400 - Project
 
It'll be a slow process I'm sure. Between my KX250, Jeep and this there isn't enough money to go around.

Any suggestions on best route to go with the carbs? Rebuild stock or go single? I don't have the air box and I've heard these carbs are a major pain to get running right on pods.

kickstand~prophet 02-01-2016 07:22 PM

Re: 1975 KZ400 - Project
 
I have a 440 LTD that would look good converted over. Hummm now all I need is the money.:deal:

philipbarrett 02-01-2016 07:51 PM

Re: 1975 KZ400 - Project
 
A word of advice from someone who just finished restoring a same year CB400F...

Although that build you've posted is certainly beautiful there's a tremendous amount of fun to be had at low financial cost just taking an old bike back to new again. Elbow grease is free, Simple Green is $5 a gallon & scouring pads about the same. The sense of satisfaction just bringing a bike back from the crusty dead is amazing and you'll not want for people to stop and ask you about it. And if you're not looking to hit Pebble Beach or the Goodwood Revival then little spots that don't come up perfectly can just be put down to character.

Looks like you have an almost complete machine there, parts are cheap & plenty. Those KZs are handsome, well proportioned machines & I'd be proud to park my Honda next to it at any Japanese historic bike meet. Here's the kicker too; they're a blast to ride these throwback machines, small, light and nimble.

If you need some help on tricks & techniques to get started I'd be pleased to share my meager knowledge.

Look how it pulls the birds too!

http://www.kz400.com/KZ400440%20ads%...20page%202.JPG

freeriders98 02-01-2016 08:44 PM

Re: 1975 KZ400 - Project
 
Yeah I'm not a 100% sure what I'll donwith it yet. I want/need to get it running before anything else.

Philip what did you do for the carbs on your Honda? Just clean and rebuild?

philipbarrett 02-01-2016 08:49 PM

Re: 1975 KZ400 - Project
 
Quote:

Originally Posted by freeriders98 (Post 1409012)
Yeah I'm not a 100% sure what I'll donwith it yet. I want/need to get it running before anything else.

Philip what did you do for the carbs on your Honda? Just clean and rebuild?

I think that's an excellent idea. I did the same it was good working on my restoration already knowing the bike ran nicely already. I ate the elephant a little piece at a time, rather than 32 bags of bolts on the floor I'd disassemble a bit, restore & re-assemble. The nice part is than you always have a bit you can feel good about and don't get overwhelmed.

As for the carbs, OEM rebuild kit and a long bath in an ultrasonic cleaner.

freeriders98 02-05-2016 09:16 PM

Re: 1975 KZ400 - Project
 
Found a guy selling a Mikuni VM36 on CL for $50! But womdering if it is to big. Seems most guys swap a VM34 in for the single carb conversion.

VM36 to big?

thrill-billy85 02-06-2016 01:46 AM

Re: 1975 KZ400 - Project
 
I'm in

Tracker 02-06-2016 08:08 AM

Re: 1975 KZ400 - Project
 
I would give the existing carbs a long soak in some good solvent and see what comes out. Gaffer tape boots?

freeriders98 02-06-2016 08:18 AM

Re: 1975 KZ400 - Project
 
My dilemma is that the stock carbs are known to be a pain to get dialed in with pods since they are controlled by a diaphragm and are best used with the stock air box which I don't have. The boots are beyond repair so I'm fabing a nee set either way.

But the cost of the rebuild kits are almost the cost of a new carb. I'm hessitant to dump money into a known problem area for the bike.

The VM36 is a killer deal, but I think its to big and I may not be able to get it leaned out enough.

TX_northstar 02-06-2016 08:44 AM

Re: 1975 KZ400 - Project
 
I have been looking for an old kZ, or another old twin to tinker on. I can't wait to see what you get in this one. For what it is worth, I like the idea of a single crab. I nearly tore my hair out dealing with old carbs (I'm not that good) on Kawi LTD in high school.

freeriders98 02-06-2016 09:17 AM

Re: 1975 KZ400 - Project
 
Yeah from everything I have read the stock dual carbs are a nightmare.

Well I've been reading as much as I can about my application and the difference between the commonly used VM34 and the VM36. Sounds like it is minimal difference and they actually share a lot of the same measurements.

So I am going to scoop up the VM36. Its brand new, didn't fit the space the other guy was planning to using it for. I'm picking it up today for $40!!!!!:trust::trust:

So now I need to finish building the manifold, get a throttle cable, throttle tube and some jets to start with!!!

I can't wait to here it fire up!!!!

philipbarrett 02-06-2016 10:39 AM

Re: 1975 KZ400 - Project
 
Quote:

Originally Posted by freeriders98 (Post 1410263)

I can't wait to here it fire up!!!!

Remember to YouTube the moment.

thrill-billy85 02-06-2016 10:48 AM

Re: 1975 KZ400 - Project
 
Quote:

Originally Posted by freeriders98 (Post 1410253)
The VM36 is a killer deal, but I think its to big and I may not be able to get it leaned out enough.

You don't think so, even with pods?

I really don't think it'll be an issue. Never played with 2n1 setup on a 4t twin, but have several times on 2t twins.

A 350cc 2t with a 2n1 can use a 38mm PWK and still not be over carbed.

freeriders98 02-06-2016 12:29 PM

Re: 1975 KZ400 - Project
 
Quote:

Originally Posted by thrill-billy85 (Post 1410293)
You don't think so, even with pods?

I really don't think it'll be an issue. Never played with 2n1 setup on a 4t twin, but have several times on 2t twins.

A 350cc 2t with a 2n1 can use a 38mm PWK and still not be over carbed.

No idea!! Guess I'll find out. On one forum someone said that since a 2stroke has twice as many power strokes as a four they require a bigger carb.

No idea how factual that is, but it does make sense.

thrill-billy85 02-06-2016 02:17 PM

Re: 1975 KZ400 - Project
 
Not really, I mean... The cylinder still draws in a finite volume if air and fuel for each combustion event.

I'll say that a 2t can handle more carb, simply because some of the charge DOES get lost in the updraft exchange process through the exhaust. This is what they try to defeat with the reverberating pressure wave in the pipe.

I may be wrong, and am missing a piece or three of the puzzle, but I think that while your lower RPM power may suffer, you engine will certainly breathe better up top.

If it is an issue, the Scary Fast, Power Now blade for the carb would help.

freeriders98 02-11-2016 05:41 PM

Re: 1975 KZ400 - Project
 
Ok so I got the Mikuni VM36 carb!!! Now trying to learn more about jetting and what jets I need to get as a baseline.

Being a Carb newbie I've got a LOT of reading to do. And it looks like the VM36 I got is set up for a power jet. It has 2 small jets in the float bowl and a hose running up into the throat of the carb. My limited understanding is that this is more for 2 stroke bikes to get more fuel/lube for prolonged top end use on the street. Is that correct? On a 4 stroke should I just block the system off?

Still have loads of work to do, before I can even think of firing it up. So I have awhile to get things sorted, understood and jets ordered. Should be a good learning experience:brainsnap:brainsnap

philipbarrett 02-11-2016 06:31 PM

Re: 1975 KZ400 - Project
 
Invaluable and far from basic. Written in an easy to understand style with lots of good pictures & diagrams.

http://www.haynes.com/products/productID/53


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