kz1000s handle wierd since they were new...

This problem.. primarily on the 70's bikes?
I have not noticed it on my 82 CRS KZ1000.

Regarding frame flex, my new V-Max was the worst!!
After installing fork braces and frame reinforcements it became a really nice handling bike.

I had a cb750 that pulled 120 with someone on the back..( i was 16 and stupid impressing a girl, wont even let someone on the back anymore) I have a 550 cruiser now thatll do over 100.. I had a gs1000 that i know pulled 120 and could have kept goin. I would think the kz's could have pulled 120 in 4th gear, no? Im amazed at the prospect of a 1000cc model that wouldnt go faster than 120..

I think the magazine tests had the KZ1000 topped out at around 125mph. Later when the GPZ1100 came out I remember it went around 135. The 1982 Suzuki Katana was the first 140mph motorcycle the magazines tested out of the box.

Kind of a silly discussion...but then again, I'm a pretty silly guy, so, here goes.

Remember that magazines tested stock bikes. Exhausts, carbs, stock air boxes, etc...
A header, some jets, and some pods REALLY wakes up a bike that was manufactured in 1978. 140?...maybe...with enough road.

My Z-1 pulled 140, but it had an open pipe and 29s and velicity stacks...and it took about a week to pull it, but we eventually got there. Don't rely on the speedo. I took mine off radar...let's just say it's good to be the fuzz.

The rest of the discussion: check all the stuff that everybody said, ESPECIALLY the steering head bearings. And as for "they say..." ...who are 'they'. These things won Daytona, you can make 'em work.

-out.

I am inclined to believe that a "NEW" KZ 1000, back in 78 would do the advertised 130 mph out of the box seeing as how my stock 78, 29 years later will do 100mph at just under 6500 RPM. With a tach redline of 8500RPM , there is enough room to squeeze the additional 30 mph. I decided not to try, mostly do to self preservation!

I have a road test reprint from a cycle magazine of a 1979 Z1 classic (1015cc) and they clocked it with radar at 132.3 mph.

My 78 can do just over 140 at the end of the straight at Brainard Raceway, but it's a loooong straight ( mile + ???) with an 80 mph running start coming out of turn 10. Bike is 1105cc, with a Kerker and jetting, and some weight loss. Most of the bad handling stories come from the racers that put slicks on and overloaded the chassis. That said I've gone through turns 1 & 2 at BIR at around 125mph (the fast guys on modern bikes do around 150 or 160) with some wallowing. I now have ZRX rear shocks and they seem to have fixed the wallowing. So maybe the stories are from when we didn't have better parts. I have put frame braces on per the old Clymers' Z1-KZ manual. Oh yea, 25 years ago I also put in tappered steering head bearing, the stock balls and races got dented and it drove like it was on BAD rain grooves all the time.

how many of you guys have ever actually had the balls to stretch one out over a period of miles at 100mph?100 mph is still hauling dont let anyone fool ya!:evil:

Just for info, Jack hit it right on the mark at 120mph measured top speed on a 1977 KZ1000A according to Cycle World. Other numbers are 120mph for a 1975 Z1, 127mph for the fuel injected KZ1000 classic in 1980, 123mph for the Suzuki GS1000 in 1978, 127MPH for the Yamaha XS1100, 126MPH for the GL1100 Honda Goldwing without all the touring crap!!! 110mph for the fastest honda CB750 twin overhead cam. No 130mph in the 70s.

So, we havn't heard from our original poster in a few, now; but, to readdress the statement of "handling" on a 1978 KZ1000 there are some obvious issues: clearly the installation of tapered-roller steering-head bearings is on the top of the "Things to do" list. But realize that your bike is 30 years old, it came with a 19" front tire stock, and rolls on high side-wall bias-ply tires on forks that are ... well ... skinny.

The bike was made during an era of the UJM. A bike that is nearly extinct today (arguements aside) was once almost the ONLY bike you could get. Back in the day most manufacturer's bikes were made for the buyer to modify-to-fit. Your bike has seen a lot of days and a lot of hours and a lot of miles. I peeped at the picture you submitted and it seems that your bike has clearly been ridden...good, but if you want it to handle then you need to put some TLC on it. To wit: bearings...they're in the steering head, the swing arm pivot, and the wheels and they make the bike do what it's supposed to do and handle the way the designers intended. Those short little drag bars aren't going to help you turn a 525lb bike with a 19" front wheel and over 28 degrees of rake at your previously mentioned 140mph, either.

At one time someone took your bike apart enough to paint the frame and the swing arm. It SHOULD HAVE gotten some new bearings when that happened...if it didn't that's just another reason to replace all your suspension bearings.

Tires: they all have a bad habit of cupping as time rolls by, as miles rack up, and as improper tire pressure exerts its impact at your previously mentioned 140mph. Just b/c they have lots of tread doesn't mean they're still "good". Run your hand over the tire along the tread and if it feels "lumpy" as opposed to the "smooth" feel of a new tire, then that is 'cupping' or sometimes called 'pucking' and they'll need replaced. Always run proper tire pressure.

If you're still around...let us know what worked...and post more pics! Good luck on your project!

-KR

OK - so I had a KZ900 25 years ago, and again now. I would agree that riding along for any distance at 100mph takes either a) some youthful bravado, or b) some real stones. 100 IS fast; the end result of any kind of misfortune at that rate of speed versus a more sedate pace is, IMHO, amplified geometrically.

Hey, more power to you if you want to do it; I pushed my KZ900 (then) up to 100 +/-, but surely wouldn't do so now -- way too many middle aged rider fatalities already.

I also grew up in an era (70s) when Detroit's finest cars weighed 2 tons or better with massive V8s. I did 120 or so ONCE in a car...until a slight bump/dip in the freeway sent us wallowing over three lanes before we could bring the 440 powered Plymouth back in line. Thank goodness it was late at night, which BTW was when most real fun happened back then.

Point is, fast is fast and bad things can happen quickly -- but I respect that it's your decision on how you ride.

well... when i took the bike apart to paint it, i inspected all of the bearings. part of the reason i took it apart was to check for cracks, or big rust spots that might make going 100mph everywhere a problem. i bead blasted it and painted it, i repacked all the bearings, that were packable, the neck has tapered bearings, and i did the "fall away" adjustment, to get the neck tight enough, but not too tight. after it still snaked, i changed the tires to new dunlop 491s, about as sticky as a 16 rear and a 19 front can get. maybe its just a little less stable than my 98 harley sportster, that im so used to.
now... this isnt what everybody should do, and im not bragging, but i go 100mph about once or twice a day on my ride to work, usualy a few miles at a time. i regularly go 100mph+ on my kawi and my harley. after this discussion got goin i put a gps in my pocked and went for a ride... top speed was 137 mph!
i guess my bike isnt stock, but that seems realy good for a 30 year old bike, i doubt its been converted to high compression, because i can kick it over with my hand...
it is lightened, no wiring harness, no center stand, no side plates, no starter motor, no signals, small gel battery, no rear chrome fender, 530 chain conversion... guess it all ads up. just so you guys know, im 27

Post edited by: archemitis, at: 2007/07/18 20:24