nd advice b4 1st start-up '80 kz1000 fuel injected

This is a 1980 kz1000 'Classic' with fuel injection. Just got her.

My battery's all charged now.
This morning I started draining the old gas from the gas tank.

IT SMELLED LIKE NEW GAS!
Maybe the prior owner put fuel stabilizer in it...?

I drained it all out anyway.

I'm about to install the battery and put fresh gas in and see if she'll start. I have never had her running, it sat idle (inside a garage) for over a year...

This is a fuel injected bike -- any advice before I fire her up? I'm clueless about fuel injection. For all I know she will run fine.

Change the oil and oil filter if the bike has been sitting. Change the gas filter. New spark plugs couldn't hurt...while you have the plugs out, turn over the motor by hand wrench using the 17mm nut under the 'points' cover. Button her up if the motor turns freely and cross your fingers.

Check the air box as well. Mice like to make homes in them if the opportunity presents itself. A year sitting is a golden opportunity

larrycavan wrote:

Check the air box as well. Mice like to make homes in them if the opportunity presents itself. A year sitting is a golden opportunity

Droid and Larry, thanks -- the mouse is reasonable. But I wouldn't have thought of it! I needed that one and will remember that in the future, as I find at my age I like buying an old bike and reviving her. I can just imagine the hassle of rodent bits being sucked in the intake tract. The bike sat in a garage at the prior owner's place next to a HUGE field, and since my house is also next to a big field I know from experience the mice population is noticeable.

And had not thought to remove the plugs and maybe spray some blaster in there and check for rotation -- thanks for that one.

There is what appears to be a stock fuel filter -- I noticed that it is about the size of a golf ball on the left side and is about 8 times the size of the normal $1 inline gas filter. So I'm gonna replace that too and also do the oil and new plugs.

Thanks guys I'll let you know if she fires.

BIKE STARTED RIGHT UP. Real healthy too.

The only problem this bike had was a low battery.
I got lucky because, with all the newfangled fuel
injection and computer stuff on this '80 Z1 Classic,
I was pretty intimidated if she wouldn't have started
right up.

There have been so many times in my experience when
the problem with the bike was the battery, these
road bikes are mighty sensitive to a battery just being
a little bit low. The prior owner was thinking it was
a problem with the coils, or the computer, or some other
electrical gremlin, nope it was just the battery.

Got lucky this time, so far so good, now I have to ride her for a while and will post if I find anything, thanks folks for your help on this.

newOld_kz1000 wrote:

BIKE STARTED RIGHT UP. Real healthy too.

The only problem this bike had was a low battery.
I got lucky because, with all the newfangled fuel
injection and computer stuff on this '80 Z1 Classic,
I was pretty intimidated if she wouldn't have started
right up.

There have been so many times in my experience when
the problem with the bike was the battery, these
road bikes are mighty sensitive to a battery just being
a little bit low. The prior owner was thinking it was
a problem with the coils, or the computer, or some other
electrical gremlin, nope it was just the battery.

Got lucky this time, so far so good, now I have to ride her for a while and will post if I find anything, thanks folks for your help on this.

Excellent.

On these early FI bikes, having a good battery was the most important thing as the computers did not tolerate voltage/current fluctuations well.

Today, to eliminate the battery as a source of issues, I pulled my known-good, almost-new battery from my 78 kz1000A2 bike after checking -- this 1980 kz1000 "Z1 Classic" with fuel injection uses the same battery.

So the Z1 Classic fired right up, and I rode the bike for about 10 minutes. LOTS OF BACK FIRING AND POPPING. And the transition from idling to 1/4 turn of the throttle was *not* smooth, I had to rev it and slip the clutch to get her going off a stop light. If I just drove it normally off a stop light, you know -- gentle roll open throttle/release clutch the normal way, the motor woulda died. Had to get the revs up and slip the clutch to get her going from a dead stop.

So she will not run well with 0-to-1/4 throttle but has power up above.

I pulled the plugs after the run, they look okay, not golden brown, but pretty darn good.

Why all the popping and backfiring when I ride her? The backfiring happens when I let off the throttle when slowing down. It also pops from 0 to 1/4 throttle as I'm cruising down the street.

It has 23k miles on her. Could bad valve clearance do this popping/backfiring? I have not checked the valve clearances yet. Could that be the problem? Everything else is fine.

By the way: the bike is all stock except for a semi-loud Kerker pipe. Since this bike has fuel injection, I don't even know if the fuel injection on these bike has to be 'rejetted for the pipe' or not.
The prior owner said that the fuel injection and everything else was completely stock, except for the pipe. I don't have the stock exhaust either.

Also, I know the difference between a minor backfire when downshifting a bike equipped with an aftermarket, less-restrictive 4-into-1 pipe. That's not what this bike is doing -- it's popping between 0-to-1/4 throttle roll-on and sometimes from 1/4-to-1/2.

So I guess I have 3 questions:
1) could out-of-adjustment valves be causing the popping?

2) could the Kerker be causing the popping?

3) or is the fuel injection dirty/clogged inside some how?

I'd check the mechanical ignition advancer, it's behind a CD sized cover on the right side of the engine.

With the engine off, see if it will twist and return to it's original position by hand.

If it's sticking, remove the bolt holding it to the crankshaft and then clean and lubricate it with light oil.
I use either 3-in-one or sewing machine oil on my advancer.

To clean the fuel injection system, use either Berryman's B-12 or Seafoam gasoline additives. Chevron fuel system cleaner is another good one.

2nd the suggestion on checking the spark advance mechanism!!!
was having all kinds of troubles with my kz900 after i bought it.. extremely hard to start,usually had to kick it and kicked back like a harley!! and very difficult taking off from dead stop.. was beginning to think i had lost my touch for riding??? mine has the dyna3 ignition.. local 900 mechanic/engine builder suggested i check spark advance..
it was stuck fully advanced. loosened and lubricated advancer..
all problems solved. one touch starting and smooth take off's nowww. amazing hopw many problems can be solved simply and at no cost!!
good luck
can you post some pic's

and apparently the advance problem might have factored into why i got a really good deal from previous owner.. because it had been stuck for a very long time..

I forgot to add that the advancer can be re-installed 180 out, so mark on it or make notes of how it's installed.