Down the rabbit hole I go

N

Nduetime

New Member
My name is Byron, currently reside in Oakland, California . To be completely honest, I never really liked motorcycles, have a hard time appreciating loud exhausts. About a year ago I came across one vintage picture of some cornering cafe racers. I sat there for about 10 minutes staring at the photo thinking how cool it looked and attempted to figure why it was speaking to me the way it was. With a peaked interest, I quickly found this forum and have been extremely impressed and excited by what I've seen.

I recently had a birthday and decided I should learn to drive ride a motorcycle to see if it's something I'd like and figured it would be a great gift for myself. I took a MSF class and felt so free driving (even if it was only in 2nd gear and on such a small course.) My father has had the same two Honda's (cb500 and cb550) ever since I could remember. But they haven't ran for roughly 25-30 years, stored in his shed. However, those are back in Indiana. So, recently I began my search for my first motorcycle.

After continuous CL searching, mostly for CB/CM/CL 200/350/360/400 and coming up with $1000 non-functioning motorcycles without titles, I decided to broaden my search. I finally found a titled bike that (mostly) runs. It's certainly a project.

The great thing about finding something that runs is, it offers me a great reference point from which I can measure my progress. My initial thought was to start with a complete basket case and build it from the ground up. However, mechanically speaking, a lot of work and money would need to be invested before I would see if I've made any errors or progress. Starting with a runner offers me the ability to make one change to one component and have immediate results, positive or negitave. Since this will be my learner bike/project, I see this to be a much better solution.

While it's not like the amazing scores I see most people find on DTT, $800 for a functioning 1976 KZ400 seemed a fair price for both of us. As I said and can be seen below, it needs some work but from what I've seen and read on DTT this can be a pretty fun bike. Thank you all for providing such great knowledge and insight, allowing me to find the outlet for my midlife crisis.

jyru5ugy.jpg
 
Welcome to DTT, Byron. Quite the interesting introduction. We all like solid intros on this forum.

Looks like you have a solid platform there and $800 is reasonable for a running, titled bike. I'll sign up to see your progress :)


Sent from my iPhone using Tapatalk
 
First you don't "drive" a motorcycle you "ride" a motorcycle. Say drive around a bike rider and you'll be frowned at ;)

Two the KZs are good little bikes. They aren't by any means speed demon but more of a cruising around style bike. Parts can be had through various means but ebay and z1 enterprises will greatly help you. You can find a lot of replacement parts matched by something else or by using stuff meant for other bikes.

And the best part of these bikes is the sheer simplicity and easyness to work on. I stripped out the starter on mine so its kick only and the amount of wiring is almost non-existant.
 
Call your father and put your dibs down on his bikes ;) Don't let him ever sell them. Not that old CB500/550's are hard to find, but you should hold onto them.

Welcome to the site - glad you found us. The KZ is a great place to start.
 
Thanks 1sttimer. I'll eventually get around to posting my progress but I'm always a bit reluctant of doing stuff like that because the last thing I need to hear is confirmation that I have no idea what I'm doing.

GroovyAardvark....I live in Upper Telegraph area. I'll certainly be checking out your build.

firebane...believe it or not, one of the things that was taught to us in the MSF class was exactly what you mentioned. Somehow I forgot, not uncommon with me. I read a lot about the lack of speed the KZ offers. As cool as doing the ton probably is, I'm completely comfortable learning to ride ;) at a much slower speed. In all honesty...I'm more into the nimbleness of a motorcycle than the all out drag nature some people are after. Windy roads for me please. I'm planning on keeping the electric start for now and focus on other aspects of the motorcycle. Later, after I've gotten my head wrapped around the motorcycle and have accomplished my first goals, I'll reconsider switching to kick only.

Tim...I called my father (very rare thing for me to do) the day after I completed the MSF course and left a message stating what I had just done and that I was in the market for a motorcycle. In typical fashion, I've yet to hear back from him. As much as I'd like to hold my breath that one day they will be mine, I know that doing so may be quite dangerous. At least I'm fortunate enough to be the proud owner of a KZ!
 
So I posted this first question in the Engine forum but figured I'd post here to since I haven't had an answer.

Bike was running at the time... I covered the overflow with my finger resulting in the engine immediately dying. Now I can't get it started. Being that this was the first time I've ever touched a carb, I'm not entirely sure what happened. My assumption is that I might have clogged the jets in the process but don't know. Is that a typical result for that sort of action? I'll be tearing into the carb later but want to learn what I did to cause this.

Some of the <a href="http://vintagesleds.com/bs/index.php?topic=80256.0">research</a> I've come up with suggest that atmospheric pressure is needed above the float bowl in order for the engine to draw the fuel. Plugging it like I did, indicates a vacuum was created and resulted in a lean condition. I suppose that makes sense but why then would I not be able to get the bike started, even 24 hours later?

Now onto another question... The throttle cable (well, throttle assembly for that mater) is not ideal, way too long. In addition, because of the placement of the carb (side mounted?) the throttle cable enters the carb at a rather challenging placement due to the tank (see <a href="http://s13.photobucket.com/user/nduetime/library/kz400">photos</a>.) Ideally, I'd like to run the cable up under the tank and out of the way. My idea was to get a 90* (or even 45*) cable elbow kit like <a href="http://jet200.com/catalog/product_info.php?products_id=132">this</a> which indicates it can be used on Keihin carbs. Aww crap...it says both are out of stock. Quick google search and I can't find anything else like it. Ideas?
 
welcome
unfortunately you will never get that carb set up to function even close to acceptable it is a poorly conceived modification with a carb off a 2 stroke dirtbike all wrong
you must go back to the original stock carb setup
 
xb33bsa said:
welcome
unfortunately you will never get that carb set up to function even close to acceptable it is a poorly conceived modification with a carb off a 2 stroke dirtbike all wrong
you must go back to the original stock carb setup
Click to expand...

Not true. Lots of people have converted these old KZs from a dual to single carb setup. There is a company that makes the manifolds for people if they want to or you can simply design your own.

I am currently running a 2-1 on my bike and I haven't had a chance to ride it yet but it idles and runs just fine.. I am using a Mikuni VM32.
 
yes if you are an experienced tuner for a noob it is really just an excersize in frustration
and to get decent perf it needs to be short and sweet like the ones that were used on british twins
 
xb33bsa said:
yes if you are an experienced tuner for a noob it is really just an excersize in frustration
and to get decent perf it needs to be short and sweet like the ones that were used on british twins
Click to expand...

Yeah that part I agree with. But there is enough knowledgeable people around and by simply asking it'll be pretty easy to tune the carb to run like they need.
 
Hey welcome to DTT. I am also pretty new here and not flush with experience... and people are being super kind and helpful. Don't be afraid to ask questions... only way you will learn.

I will bookmark this thread so I can follow your learning progress! Good luck!
 
Alright. Finally got the bike running. However, I have a high idle problem (something I knew when I purchased the bike.) When started, the idle is up to 3500-3800 rpms. I'm going to ask my more specific questions over at kz400.com and kzrider.com. However, I think I'll ask this question here.

After changing the oil/filter tonight, I started it up and noticed smoke coming from under the bike. Traced it to and exhaust leak. Would a substantial exhaust leak cause high idle? If nothing else, indirectly? My thought is that a substantial exhaust leak would affect the jetting, causing it to run richer/leaner than it would if there was no exhaust leak, correct? I'm assuming this because I've read that the carb/s would need to be rejetted if changes are made to the exhaust (ie going to a 2-1 exhaust or removing baffles.)

So I have a 2-2 exhaust. Without any experience with bike exhaust, I didn't really question what my pipes looked like under the bike the past 2-3 weeks. However, I knew it didn't look right. According to the photos from this <a href="http://www.ebay.com/itm/Kawasaki-KZ400-B1-1978-Exhaust-System-Mufflers-/231047415996">78 kz400 exhaust on ebay</a>, there should be a center pipe that connects both pipes. At one point I'm almost certain mine had it. However, now, it looks like someone chopped it out about 1-2" from each pipe and maybe attempted to crimp it shut. In any event, I'm sure it's not helping the bike's performance nor my distaste for loud exhausts. I'll add an new/er exhaust to my list of thing to buy in the near future.
 
Nduetime said:
Alright. Finally got the bike running. However, I have a high idle problem (something I knew when I purchased the bike.) When started, the idle is up to 3500-3800 rpms. I'm going to ask my more specific questions over at kz400.com and kzrider.com. However, I think I'll ask this question here.

After changing the oil/filter tonight, I started it up and noticed smoke coming from under the bike. Traced it to and exhaust leak. Would a substantial exhaust leak cause high idle? If nothing else, indirectly? My thought is that a substantial exhaust leak would affect the jetting, causing it to run richer/leaner than it would if there was no exhaust leak, correct? I'm assuming this because I've read that the carb/s would need to be rejetted if changes are made to the exhaust (ie going to a 2-1 exhaust or removing baffles.)

So I have a 2-2 exhaust. Without any experience with bike exhaust, I didn't really question what my pipes looked like under the bike the past 2-3 weeks. However, I knew it didn't look right. According to the photos from this <a href="http://www.ebay.com/itm/Kawasaki-KZ400-B1-1978-Exhaust-System-Mufflers-/231047415996">78 kz400 exhaust on ebay</a>, there should be a center pipe that connects both pipes. At one point I'm almost certain mine had it. However, now, it looks like someone chopped it out about 1-2" from each pipe and maybe attempted to crimp it shut. In any event, I'm sure it's not helping the bike's performance nor my distaste for loud exhausts. I'll add an new/er exhaust to my list of thing to buy in the near future.
Click to expand...

Leaky exhaust will make the bike run rough also check the rubber boots where the carbs connect. Being as old as these bikes are these boots have a tendency to crack causing air leaks which can make the bike idle erratically too.
 
Yeah, it's been converted to a single carb with a copper manifold by the previous owner. I sprayed a little wd-40 on the boots and didn't really notice any change in the engine speed. I think I'll spend a little more time exploring the boots in the next day or two. I'd assume carb cleaner would work as well?

I'm thinking I'll explore the 11th hour industries manifold options quicker than later. One less headache.
 
Nduetime said:
Yeah, it's been converted to a single carb with a copper manifold by the previous owner. I sprayed a little wd-40 on the boots and didn't really notice any change in the engine speed. I think I'll spend a little more time exploring the boots in the next day or two. I'd assume carb cleaner would work as well?

I'm thinking I'll explore the 11th hour industries manifold options quicker than later. One less headache.
Click to expand...

11th hour would definitely be a way to go for these bikes. But take into consideration that by switching to a single carb setup you will have jetting issues out the wazoo which means a lot of trial and error to find what works for you.

Jetting issues can also be a reason why the bike is idling extremely weird.

Do you have a good close up of the new manifold that was created?
 
I'll take a photo of the previous owners work tomorrow afternoon. I'm thinking it probably could use a bit more solder, maybe there's a small pin hole or two. Again, I'll spray some more around the boots and manifold to be certain. On your setup firebane, is your manifold from 11th hour, somewhere else, or did you make it? It looks like its a straight-shot setup and not one side. However, the information on 11th hour's website shows it for 78+ (I'm assuming because of frame clearance issues on our earlier bikes.) Also, what k&n filter are you running?
 
Also, forgot to mention. The previous owner purchased and included ~5 different jets. Said he had been battling the jetting since the conversion and couldn't get it any better. Figure I can get it better than where it is now hopefully.
 
Nduetime said:
I'll take a photo of the previous owners work tomorrow afternoon. I'm thinking it probably could use a bit more solder, maybe there's a small pin hole or two. Again, I'll spray some more around the boots and manifold to be certain. On your setup firebane, is your manifold from 11th hour, somewhere else, or did you make it? It looks like its a straight-shot setup and not one side. However, the information on 11th hour's website shows it for 78+ (I'm assuming because of frame clearance issues on our earlier bikes.) Also, what k&n filter are you running?
Click to expand...

I don't have an updated picture of mine right now but I made my own. I took the old boots and burned the rubber off leaving the metal flanges behind for material to weld the tubes too. My setup is simliar to the 11th hour as like you said the older frames have the neck in the way and they have to be turned out to the left or to the right. I turned my out to the right and it angles up slightly and towards the back of the bike.

I don't recall the K&N filter I am using but it is similar to this one https://www.adaracing.com/scooter/air-filter-k-and-n-pancake/knrc-0340 and I am using a Mikuni VM32 carb on my bike. I haven't had a chance to tune or tweak the carb yet but I have added a new main jet and needle jet and hoping to get the bike going again this spring.

This whole single carb has not been a cheap thing to do either. The carb cost me about $150 the manifold was about $80 and the jets came in around $10 and I'm still not anywhere near done.

But yes the second you throw a unknown condition onto a bike such as a new manifold, exhaust, filter, and carb headaches will ensue to get jetting proper.
 
I appreciate all your help. This may sound terrible but I'm under the impression I'm running rich. Is there any way to confirm this besides checking the plugs?
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light
    • www.jadusmotorcycleparts.com
    www.lostapostle.ca/
    www.sparckmoto.com

    Spread the Love

    Back
    Top Bottom