Topic: I think this bike would take my K1 in a drag race.

[GNXFan]

Me and a friend just got this bike running after being parked in 1986. It's a 1978 Kawaski KZ650.It runs like a top and doesn't have the stupid clutch rattle like my 750. I really think it would outrun my K1 even though it's a 650. It has 15K miles on it and it's all original except for the tires and the new mufflers.I hate  the goofy seat and the sweptback handlebars but it has similar styling to the Z1900. Got all the parts I needed form Z1 Enterprises by the way.

[754]

I ran against them at the drags, they are pretty quick, them and the 750.. newer design that part of the z-1 rubbed off on..


If you have a stock cb750 you will probably end up looking.. not so good..

[mlinder]

It shouldn't. Makes similar HP and weighs a bit more.
Nice bike, though.

[Tim.]

Could just be geared for quicker launches.  Nice bike!

[crazypj]

It has shim under bucket, direct cam operation so valve float isn't as much of an issue when you over rev it. Very nice motor, probably the only Kawasaki I ever really liked

[Terry in Australia]

They could kick a CB750's arse when they were released, so no reason to think they won't now. Nothing to be ashamed of, it's called "progress". Cheers, Terry.

[KB02]

I know the KZ550 that I had was a strong little bike.

[mlinder]

They could kick a CB750's arse when they were released, so no reason to think they won't now. Nothing to be ashamed of, it's called "progress". Cheers, Terry.

78 kz650
HP 66
weight 505 lbs

70 cb750
HP 67
weight 480 lbs

Progress is great.

Numbers are numbers, though, and there is no way the 650 is going to win the 1/4 mile in this scenario unless the CB is geared completely wrong.

[754]

A K0 might beat it, but try it with a K4 or K5..same era.

 Now if you drag out the old 500 Kaw against the K0...then..
....................................


depends on the rider as well, magazine HP is just a number, take a stocker to the drags and see if you can match what the magazine said it would do...

[mlinder]

Right, as I said,  K0 and probably a K1 would take it.

Hondaman was dynoing K0's and K1's at greater than 60 rear wheel HP when they were new.
That tells me they were making MORE than the 67 hp at the crank that honda claimed.
They also claimed a top speed of 120 mph or so. I've seen faster than 120mph, and so has Hondaman.

The OP said he thinks the kz could take his k1. I'm saying that, with both engines fresh, I don't think so. The numbers back that up.

[ekim98]

depends on the rider as well, magazine HP is just a number, take a stocker to the drags and see if you can match what the magazine said it would do...

I took my 85 650 Nighthawk to the strip and ran a 13.06/ 106mph and the magazines said they got 12.64/107mph. I was quite happy with that.

[GNXFan]

I forgot to mention this bike not one but two rim locks on the rear wheel. I wonder if the factory thought that the torque was so great that it might spin the tire off the rim or if was just typical for Kawi to do that back then. 

[754]

Magazine figures and dyno numbers are apples

Dragracing is oranges..


I saw a Honda 600 in Sept that dyno'ed 210 hp.. and it only ran 191..  first day..!!!

 There was a bike there that had 500 hp, but I bet he did not go faster than the 2 busa's that ran 240+

I got a question, how much difference between dynos? or do they all use something so the results on different machines are very close? How is that done??

[mlinder]

754, while dyno numbers are not alone indicative of how welll an individual bike will do with an individual rider in the 1/4, we can assume this:

Given same track, same day, with the same rider, and the same traction, if one bike makes more HP and weighs less, it will run the 1/4 mile faster. You can't argue basic physics.

[754]

The tires may not be the same,
You forgot about clutches, handlebars, tank height. whelbase.Transmissions and ratios from 2 different manufacturers...Some bikes are eay to ride hard off the line..some not..(Kawi triple)

Yes the higher HP lighter bike SHOULD win.. on paper..
 but that is not rubber meeting pavement.

Question for you how many times have you drag raced??
against a time clock?

[Hope]

Before I put my dad's CB550 on the road, I had a Kawasaki KZ440LTD.  I think the KZ440LTD would take a CB750 just because of the gear ratio.  That little 440 was quick off the line.  My dad really wanted to trade me his 550 for my 440 because he thought I would kill myself on that 440.  He was probably right when he said the 550 would have suited me better than the 440, but I was younger than I am now, and I like the way the 440 looked like a cruiser and was geared like a sports bike.  I wouldn't trade him....  oh, it was sweet, but it was a pain in the a** to find parts (LTD=Limited Edition).  When the carbs were shot, there were no parts in sight for my little bike, plus dad passed away so I didn't have any help in working on the carbs....  One day I searched ebay and found pages and pages of parts for the 550....  The 550 was put back on the road in no time, and I sold the 440.

[mlinder]

The tires may not be the same,
You forgot about clutches, handlebars, tank height. whelbase.Transmissions and ratios from 2 different manufacturers...Some bikes are eay to ride hard off the line..some not..(Kawi triple)

Yes the higher HP lighter bike SHOULD win.. on paper..
 but that is not rubber meeting pavement.

Question for you how many times have you drag raced??
against a time clock?

754, the K0 (and probably the K1) is a faster bike than the kz650.
As I stated, assuming equal traction (tires and surface), the 750 is a faster bike to the 1/4 mile line.
Samr rider, same surface, same tires, the early 750 should beat the kz650.

I haven't done dragracing. I have roadraced. I've been riding for close to 30 years.

Even 'magazine' 1/4 mile tests put the K0 at a faster 1/4 mile time.

[Terry in Australia]

They could kick a CB750's arse when they were released, so no reason to think they won't now. Nothing to be ashamed of, it's called "progress". Cheers, Terry.

78 kz650
HP 66
weight 505 lbs

70 cb750
HP 67
weight 480 lbs

Progress is great.

Numbers are numbers, though, and there is no way the 650 is going to win the 1/4 mile in this scenario unless the CB is geared completely wrong.

Ha ha, where are you pulling those numbers from mate, your memory? Here is a direct comparison of the 1978 models from "Motor Cyclist" Magazine's "Great Bikes of the 70's"

Honda CB750 F2: (recognised as the fastest CB750)
Weight 522 Lbs
68 BHP @ 9000 RPM

Kawasaki KZ650:
Weight 475 Lbs
70 BHP @ 8500 RPM

Where did you find a 480 Lb CB750? Even the K0 with it's lack of "bling" was well over 500? Anyway, all "theoretical" bullshiite aside, I know the Kawa 650 would crap on a CB750, because I've had first hand experience, back in the day when both bikes were fresh.

Back in 1978 I bought a new CB750F1, (it was a discontinued model, the F2 was out by then and the dealers couldn't move the old stock) and an Army buddy bought a shiny green KZ650. Not only would that bike kick my F1 in a straight line any day of the week, it handled superbly and stopped better too.

I had the opportunity to swap bikes and race against my own bike as well, but it made no difference, the Kawa was king! If you really know your CB750's, you'll know that the F1 was no slouch, either. Whether you like it or not, you can't re-write history. Cheers, Terry.

[mlinder]

My K0 doesn't weigh 500lbs.
Even when it had all the stock #$%* on it.

Stock weight for a K0 is 485lbs
Dunno what the F2 weighed.

Depending on the year, the kz was 480 to 505 lbs.
HP claim, form kawasaki, was 64 hp.

Best 1/4 mile for kz650? 13.19.
Best 1/4 mile for K0? 12.6.
1/4 mile for a k2 with a 17 tooth countersprocket? 12.9

So I don't know what the #$%* you are talking about. You're wrong. Sorry, Terry.

[Raul CB750K1]

Z1's and their next generations are so coveted today that I have given up to ever have one. I also thought about the "lesser brothers", like the KZ650 or even the KZ400 -I wrote here about a guy who was going to give me one for free but changed his mine after seeing my interest-

But, even if Kawas are quicker than Hondas, if you are missing an engine part your bike can't run at all, and the price and availability of classic Kawa parts made them bikes not suited for the impatient or the one with a tight budget. Some people complain about price of Honda parts, but it is a low price to pay when you have parts available in a couple of days.

Terry, I have written for a spanish magazine. Part of the articles included the bike specifications. I have a pretty decent motorcycle library, and you would be surprised how many times the specifications change from one book to another. In those cases, I would just choose the figures that appeared the most, in the -innocent- thought that if they are quoted more times, there are more chances they were the correct specifications.

[Terry in Australia]

Thanks Raul, so with your extensive library, can you please post the correct weights and BHP figures for both bikes? (standard bikes thanks, with factory gearing etc)

I suspect strongly that Mlinder is making up his "specs" as he goes along. It's almost as if "Silicon Doc" had come back to pay us a visit............. 

[GNXFan]

Be nice Guys!! I started this post only because I had thought my 750 was just so bad to the bone but my attitude changed after riding the KZ. It does have great brakes as stated in a previous post by the way. As far as the 750 weight issue my K1 owners manual states the weight at 480 lbs. or 218 kg.Horsepower is stated at 67@ 8,000rpm.

[mlinder]

Thanks Raul, so with your extensive library, can you please post the correct weights and BHP figures for both bikes? (standard bikes thanks, with factory gearing etc)

I suspect strongly that Mlinder is making up his "specs" as he goes along. It's almost as if "Silicon Doc" had come back to pay us a visit............. 

Prepare to eat crow.
Course, you always backpedal or dismiss crap you don't agree with anyway, regardless of material.

Why don't you ask hondaman what the 1/4 mile times were for cb750's? You gonna say he's pulling those out of his ass, too?

[mlinder]

Be nice Guys!! I started this post only because I had thought my 750 was just so bad to the bone but my attitude changed after riding the KZ. It does have great brakes as stated in a previous post by the way. As far as the 750 weight issue my K1 owners manual states the weight at 480 lbs. or 218 kg.Horsepower is stated at 67@ 8,000rpm.

I think your bike is kick ass, and sure would not mind having one myself.

[Terry in Australia]

Thanks Raul, so with your extensive library, can you please post the correct weights and BHP figures for both bikes? (standard bikes thanks, with factory gearing etc)

I suspect strongly that Mlinder is making up his "specs" as he goes along. It's almost as if "Silicon Doc" had come back to pay us a visit............. 

Prepare to eat crow.
Course, you always backpedal or dismiss crap you don't agree with anyway, regardless of material.

Why don't you ask hondaman what the 1/4 mile times were for cb750's? You gonna say he's pulling those out of his ass, too?

No, I believe Mark, but I've been reading some of your recent posts, and I doubt your credibility entirely.  How's that crow coming along?