A Tale of Two KZ's

After retiring last winter, I made a deal with a man in town who had two KZ's.  I would get his KZ1100 roadworthy and he would give me an '81 KZ1300A3 as payment.  The 13 hadn't been operated since 1989 with 5000 miles on the odo, but the 1100 had been run at least run another five years or so since..

I had stuck my neck out since I wound up spending much more money on the 1100 than anticipated, but I got it roadworthy, had fun doing it, and learned a lot.  Come early spring, I took delivery of the 13.  I took a good chunk of summer off riding, maintaining my other girls, and tuning my son's Ninja, but finally took 'Mad Max' on his first ride three days ago.  The 'before pics', which are obvious, is exactly how she looked on delivery into my shop with rear air box off and electrical components hanging out the right side.  At least he had the courtesy of draining the carbs before he parked it which is more than I can say of the 1100 which was a mess.  The first thing I did was get a bucket of water and sponge and removed some dirt so that I could see what I was doing.

It is stock save the fairing and trunk, though I'm not sure about the seat.  Two brake lines were too clogged to clear and had to be replaced.  Near as I can tell, the rear tire is stock, the front had been replaced, but both hold air so I'm getting money's worth out of them.  All electronics and gauges work except the headlight's low beam barely illuminates.  

The cooling system works immaculately.  A lot of heat pours onto my legs but at least away from the engine.  I suspect the thermostat was stuck the first time I ran it because it got a bit warm, but remained cool since.  I have even motored around town in low gear and it stays just in the lower warm range.  It cools so well, I had to check all the fan components per the service manual just to verify that it works.  

It is an absolute beast, comparable to a Gold Wing in weight and handling, but without the engine sticking annoyingly out the sides.  I find it more comfortable than a Gold Wing and I will use it as an LD tourer.  The trunk has a backrest and the wife says it's more comfortable than our old Wing (which I scrapped after a year; I hated it).

The carb boots are incredibly pliable as if new.  I'll spare my carburation adventures, but have sealed the airboxes behind the carbs with a Permatex non-hardening sealant.  I still have low-end matters to fine tune as the throttle still is not snappy, the RPM's hang a little, and doesn't idle well until completely warm, but I have Seafoam in the tank, it runs better the more I use it, and the spark plugs look almost normal as of yesterday.  This is an American bike, so the idle screws are covered with plugs and I don't know how to get to them or figured out which are the low-end passages.

I live one mile from an 80 mph Interstate highway, already had it up to 85 or 90, and am looking forward to blowing out the cobwebs more this weekend.  Glory to God for helping me with this project.  My wife didn't think I could do it.

Here in the American Midwest, there are lots of bikes in barns, you just have to find them.

Wow, what a transformation.
The aluminum plugs over the mixture screws are pretty easy to remove. Find a small self-tapping screw that will easily within the diameter of the plugs. Put a suitably sized drill bit in your drill, and wrap some tape around it to prevent the bit from going more than about 1/8 inch deep. You do not want to drill into the mixture screw as that could cause damage to the metering end of the screw. Once you have drilled through the cap (it is thin and soft), start the self-tapping screw into it and use pliers on the head of the screw to pull it and the plug out.

If one of those tires is original, and the other was relatively new when the bike was parked, I would not ride across the street on them. The rubber deteriorates with age, and you may have a couple of blowouts in the making. Such a heavy bike on really old tires at 90mph is just begging for an ambulance ride.

wrote:

The rubber deteriorates with age, and you may have a couple of blowouts in the making.

I was going to mention the same thing. Aged tires can also have much less grip. So even if they don't come apart they can be pretty unsafe.

www.liveabout.com/the-science-of-tire-aging-3234377

I had some drama today.  I set out to do some miles for a couple of hours and check the mileage and comfort level.  Definitely not a sport-tourer.  About 35 miles on the Interstate it begins to bog down.  At the same time, the plastic/chrome looking cover on the left side flies off.  The previous owner had broke a tab but I didn't think it would go anywhere.  It eventually stalls and I coast to a stop.  A few minutes later, he starts and pretends like nothing happened.

I exit, top off the fuel, and the good news is that I'm getting about the posted 25 mph despite 80 mph.  I head home and it does it several more times at greater frequency, but I make it.

Now I need to figure out if it's the fuel relay thingy known for it's high failure rate or possibly vaper locking.  I had installed an in-line filter and hope that the fuel's not getting too hot...  Since the first leg was fine, that is not likely.

The front brakes are gripping, but making some kind of tapping sound.

At least the tires didn't blow.

Maybe check the vent in the fuel cap?  A stuck vent could cause it to starve for fuel and then just go back to working.

Might be the filter. If it has a paper filter media, or is designed for a pressurized system, it will cause the symptoms you describe.

Seat is after market, not stock, not trying to be an ass but you have rocks in your head if you think you are "getting your money's worth" out of those dangerous old tires, I've ridden everything over the last 40 odd years and there's no way in hell I'd ride any bike on tires that old let alone a behemoth like the Z1300, do yourself a favor {and save some skin} and het some new tires, Its a bike, not a car.....{would still be dangerous on a car....}

TexasKZ, what filter are you referring to?  The tank vent line has what appears to be plastic filter but looks like it's empty.

I did find a slight kink in the same line last night and rerouted it.  I had it routed according to the service manual but that's not working.  I checked the connection for the fuel solenoid and it was like new, but cleaned it anyway and will test the bike today.

I took apart the gas cap, not sure but I was looking for, but cleaned it up anyway.

wrote:

TexasKZ, what filter are you referring to?  The tank vent line has what appears to be plastic filter but looks like it's empty.

I did find a slight kink in the same line last night and rerouted it.  I had it routed according to the service manual but that's not working.  I checked the connection for the fuel solenoid and it was like new, but cleaned it anyway and will test the bike today.

I took apart the gas cap, not sure but I was looking for, but cleaned it up anyway.

My bad. I could have sworn I saw something about a fuel filter earlier. However, an inline fuel filter is a good idea, especially on a tank that sat for so long. I really like the Golan Super Mini. It filters much finer particles than cheaper filters, and the media is washable, so the filter never needs replacing. There are cheaper filters, just be sure you get one designed for a gravity feed system. You have mentioned the fuel distribution thingy and the fuel solenoid. Are you talking about the fuel tap, often called the petcock, on the bottom of the fuel tank? The rubber parts in it need to be replaced, and the seat and the face of the selection lever that goes against the seal need to be carefully polished. If those surfaces are badly pitted, the valve will need to be replaced. A petcock that is clogged or sticking will cause the symptoms you mention.

EDIT: I decided to take a look at the parts diagrams before sticking my foot in any farther. The fuel tap seems to be mechanical rather than vacuum operated as I assumed. If so, there are no rubber parts, but it does need to be spotlessly clean inside and working as designed.

No mention of the condition of the inside of the tank.  Much rust can be hidden on the inside top of the tank where it can't be seen without a mirror.

Gradual bogging to the point of the motor dying sounds like fuel starvation.

Have you removed the petcock & rinsed the inside of the tank to check for debris?  Fine rust particles can plug the petcock.

If there is (was) rust particles, ridin' will shake them loose.  As the loose rust collects at the bottom of the tank & petcock, fuel flow will progressively be choked off especially if running on reserve, perhaps to the point of fuel starvation.  Also, make sure the standpipe for the non-reserve position is present & sound.

Stopping would allow some fuel to refill the float bowls, allowing restart & some ridin'.  It would be a cumulative process, choking fuel flow more & more as miles pile up, leading to dying more often.  If fine rust particles are in the fuel they will rapidly clog the filter, also limiting flow.

Good Ridin'
slmjim & Z1BEBE

Like slmjim said, a fuel filter will clog pretty quickly if your tank isn't decently clean. Be sure to carry the tools to open and clear out the filter if you go that route.

Placing the petcock on Reserve or On had no effect.

The 'fuel thingy' I referred to earlier which has the high failure rate is the 'solenoid fuel valve' which keeps gas from draining into the carbs when not running.

The fuel tank didn't look bad when I first evaluated the bike, so I didn't remove it because they are bears to seal again.  So, I installed a clear filter so that I can see what's going on.  It is catching particles but is far from clogged.

I ordered a set of Avons today and, after rerouting the vent tube and checking the solenoid fuel valve connection, I took it for a ride though much slower than yesterday.  Beautiful starting out and running even better at low speed.  This time I got less than twenty miles before I noticed it very lightly lagging and surging, then a loss of power correctable with more throttle before killing.  I turned off the key, coasted to a stop, and when I turned on the key, fuel is surging into the filter.  Then it started and allowed me to shift into five before the cycle repeated.  I got farther each time by keeping the speed down and got it in my shop.

I removed the tank and petcock.  There was a minute amount of rust at the bottom, nothing that will come close to clogging the screen.  I will next bypass the solenoid and see what that does.  I know to turn the petcock off when not in use.