An early goodbye?

As I was riding home today, my 1980 kz440-B1 started making a weird clacking noise (like a deep-pitched baseball card in bike spokes) and subsequently died on the freeway. At first it wouldn't start back up, but after waiting a few minutes, it would start, make the same noise, and die again if I had to downshift. I walked it to a local shop and was told a bushing from a crankshaft connecting rod probably gave out and that actually opening it up and finding the broken part would be more trouble than the bike is worth. I don't know what to do. The shop-man told me that replacing the entire motor is the only practicable way to salvage my beloved bike that I've only had for a few months. Do I have to say goodbye so soon?

Get a second opinion. I would never not look into a motor that quit running. Parts for theses bike are generally still available

saucedogg wrote: As I was riding home today, my 1980 kz440-B1 started making a weird clacking noise (like a deep-pitched baseball card in bike spokes) and subsequently died on the freeway. At first it wouldn't start back up, but after waiting a few minutes, it would start, make the same noise, and die again if I had to downshift. I walked it to a local shop and was told a bushing from a crankshaft connecting rod probably gave out and that actually opening it up and finding the broken part would be more trouble than the bike is worth. I don't know what to do. The shop-man told me that replacing the entire motor is the only practicable way to salvage my beloved bike that I've only had for a few months. Do I have to say goodbye so soon?

That phrase just means the repair cost exceeds the resale value. But if you like the bike, you may want to spend the $ to fix it. I rebuilt the motor on my '79 KZ-750 and spent more than the resale value, but I wanted to keep the bike running.

That clacking noise may be a con rod bearing failed that is binding up the bearing. Could maybe be the internal drive chain. No way to know until it gets looked into. Getting a running used engine is always an option.

If your plan is to use a shop for all your repairs, your "shop-man" may be right. If you have to pay someone to go into the engine, it will likely cost more than the bike is worth. These old bikes will either teach you to become a mechanic, or drive you into the poorhouse paying someone else to keep them running. Just search here for carb problems. They pop up all the time, even on routinely ridden bikes. If you have to pay a shop every time your carbs get dirty, the carbs themselves will cause your KZ to become a very expensive form of transportation.

If you want to keep this bike, I would dig into the engine as much as you can. If you can't find and/or fix the problem, I'd find another engine. I haven't priced 440 engines, but I wouldn't think that they were too expensive.

It sounds like it might make a good Winter project. If you pull it apart and fin that it really is a connecting rod bushing you may want to try replacing them and see if the noise goes away. The Kawasaki Service Manual should serve as a good guide for the repair. Here's one place that has the bushings in stock; just plug the part number (see diagram) into the page the link brings up. Ed
www.themotorcyclepartsoutlet.com/cgi-bin/store/index.cgi

The symptoms do sound like a spun bearing. A spun bearing very often kills the crank as well. That said, you would likely spend a lot of money to fix that, and as projects go, it's fairly advanced.

On the other hand, you might find a whole motor (or parts bike) at a wrecker or perhaps Craigs list for cheap. Swapping the motor out is a couple hours work and isn't a difficult task. Depending on your experience level, this might be a good path to developing a bit more knowledge and confidence before tackling more complicated tasks.

Once your old motor is out, you can tear it down and decide if you want tackle a rebuild at your leisure.

Just a thought.....

Crank would most likely need to be turned, rods resized along with new rod bolts if it is the rod bearings.

As for what is the cause, who the hell truly knows until you open her up....

As for if she's worth going in, all depends on you.
Some of us enjoy the challenge of taking a 30 year old beat to death girl and fixing her up. Splitting her open, going into her depths, examining WTF etc.... and of course spending ridiculous amount of $$$ regardless... We're a sick bunch that way. :laugh:

Case in point, will I truly ever get my $$$ back from my build, nope not going to happen but I didn't build her for the return investment. It's my hobby/passion, ok screw it, my OBSESSION..... :whistle:

So if you're one of us sick &twisted, that enjoy then by all means get after it (winter project).
If you don't have the tools, space, time what ever then obtain a another project build cheap for the engine./parts

Or, take the hit and get yourself a KZ900/1000 and sell this one for a parts bike/project....

sbc1320 wrote: Crank would most likely need to be turned, rods resized along with new rod bolts if it is the rod bearings.

No. Cranks are "ground" on a crank grinder, not turned, and undersized bearings are not available for any KZ, as far as I'm aware.
The three sizes listed in the manual only vary by around 0.0015" or so, just to correct production tolerances.

If you can find a real, experienced mechanic, then he/she can tell you what's wrong by listening to it.

I'll give you a hint, if it knocks under acceleration , it's not a rod bushing.

There is an add for a low mileage 440 motor in Craigslist Portland. No carbs or exhaust.

$150
503-309-4180

I'll definitely look into this. Thanks everybody for the helpful advice.

It is very easy to pull the engine, flip it over, and pull the bottom half of the case off. This will allow you to pull the crank bushing cap off and you can examine the bushings and the crank journals.