82 KZ550 kind of general questions

Ok so I just have a couple things I want to get squared away so I can check them off the to do list.

The first problem i'd like to resolve is that my bike is hard to start. Even if I charge the battery I still have to try it a good couple times before it will start. If I spray a little burst of starting fluid into each of my four air filters and turn the choke all the way on it will start first start every time and start fine once its ridden some where. But if I leave it parked while im somewhere for too long i have to spray it again. Any suggestions?

Also what maintenance to I need to be doing on a regular basis? Its the first bike ive ever had and I really dont know. Havnt really looked in to it I just thought Id ask, ill probably jump on google right after this and see what I can find.

Also when I am riding its like my throttle hits a rough spot. Id say between 1/4 and 1/2 throttle (give or take) the engine almost seems to bogg down or have a rough time keeping up and sounds rough as well but then once I pass half throttle or so it sounds AWESOME and has great acceleration no problems. It also sounds like its running properly when first getting in to the throttle, any suggestions?

I'm going to post this in the engine AND electrical forum if thats ok because I couldn't decide which one it belonged in

id say start with a good tune up.
then start at front and work your way to the rear checking everything in between to get to know your bike.

The battery on the KZ550's must be in top notch condition. It can be strong enough to spin the engine over, but with the headlight on, the spark can be weak. If there is any doubt, replace with a good quality new battery. If the plugs are not new, replace with NGK or ND plugs. NGK's are what I like. Make sure the gap is correct. As Mr. Plummen was nice enough to point out, that is a good starting point.

Hard to start? VALVE CLEARANCES OUT OF ADJUSTMENT. Valve seats wear and you have to periodically check the valve clearances.


Here's an example. I have a GS1100 Suzuki. The main reason the seller sold it (real cheap too) was -- it had the same symptoms as your bike.

I got her home, did the valve adjustment (took less than 1 hour and I had to have the shop manual for the bike to do it) and -- the bike went from having to keep the throttle wide open and crank and crank on the starter button for WAY too long -- to starting almost instantly with a little choke and just pushing the button for a second or two. HUGE difference. It was the first time I had ever witnessed a hard-starting bike so amazingly cured of that problem, and from that point on, 'valve adjustment needed' is the first thing (besides battery) I suspect when 'hard to start' comes up.

In addition to your valve clearances, get a voltmeter. With the ignition off, read the voltage across the battery. You need to see over 12 volts (12.6 volts would be perfect, since each cell puts out 2.1 volts). Now turn on the ignition but don't start the bike. With the ignition on, if voltage is below 10 volts, try trickle charging the battery and make sure you charge it to 2.1 volts x 6 cells = +/- 12.6 volts.

Then re-do the voltage check again (bike ignition on, not started, should read above 10 volts across the battery) -- this is a very simple 'load test,' you have the ignition to the bike turned on thus putting a 'load' that the battery has to support, and it needs to stay above 10 volts.

If the battery is too low you may need a new battery.

I'm actually trying to figure out (in another thread) if I can buy a generic battery for my '81 kz650, so good luck with yours.

By the way, other minimum tune-up stuff:
- new and correctly-gapped spark plugs
- new oil and filter if not done in most recent 3000 miles or 12 months
- check air filter, are they dirty

Think about getting a new set of ignition coils and sparkplug wires too. Even new from the factory, the stock coils were marginal, add years of vibration and heat, and now it's time for new ignition componets.

Accel and Dyna make good replacements, Z1 enterprises sell coils too.

One of the best investments you can make is in a factory shop manual. That's the one published by Kawasaki. They come up on eBay now and then and may also be available online for free. The fsm clearly lays out the routine maintenance needed for this particular bike and has good troubleshooting sections as well. The next best investment will be in quality tools and in developing a good relationship with the folks on this site. There's about a million years of experience here and most folks are happy to help sort out problems.