Topic: cb 750 versus z1 900 any thoughts

[8 Track]

Do i drive a car.. hell no.. .. I know people that got killed in them....

Thank you.  Somebody else says this, too.  Every time somebody tries talking me out of owning a motorcycle because they know somebody who was injured or killed, I ask them if they've ever been in an auto accident or know of anybody who has.  Then I ask them... "And you still drive a car?!?"  Shuts them up every time.  No duh they're more dangerous; be more careful.  Anyway...

This is a very fun thread to read.  I was three when I got my first motorcycle ride.  It was on a '73 h2.  My dad owned a denco shop and did the modifications to the h1 and h2 triples.  I still have some of his notes in the service books.  He bought a '76 kz900, installed a 1000 cc kit and that bike would run a 10.80.  When I was old enough to get a bike, he suggested a cb750.  Although the Kawi was faster, the Honda just plain held up better.  They both have a beautiful sound, too.  Now, he wasn't worried about me getting a fast bike, because he let me start riding on his 1980 gs1100.  Although no time was recorded, the gs would outrun the kz on the street, every time.  Switch riders, gs would still win.

These bikes are apples and oranges.  It's obvious Honda just continued tweaking their design through the 70's, while Kawasaki kept going faster.  But personally, I'd take the z1 or kz's.  It's a better looking bike, in my humble opinion.

[754]

I was looking at an April76 Cycle World.
 Had a several part article on DuHamels Kawi Superbike,
 Some of the mods;
 carbs bored to 30mm from 26mm
 Headwork, including movint seats or valve contasct higher in head, done by Dale-Star.
 Partly gutted, shortened stock pipes.
 MAGnesium Morris Mag
 Sprayed aluminum rotors..

 bunch of other tricks.. interesting article..

[seanbarney41]

Want some more vintage Kawi articles to read?  Go here
http://kzrider.com/index.php?option=com_kunena&Itemid=116&func=view&catid=13&id=352699
I think the article you mentioned might already be in there.  If not, I know the original poster would love to see it.

[Stev-o]

You want to see the ugliest Z1 ever made?!?

http://cgi.ebay.com/ebaymotors/Kawasaki-1975-kawasaki-z1-900-z1900-chopper-bobber-/220719007036?pt=US_motorcycles&hash=item3363e0c53c

[Dave K]

I had just bought my 750 K3 new, when the Z1 came out. I was crushed! I thought I had the ultimate bike at the moment and Kawasaki just took all the wind out of my sails. Now, to be fair to the other bikes and those that rode them. I had just before the K3 a '70 Kawasaki 500. That bike as a SOB. It ate pistons for breakfast and then the CDI for lunch. I swore, when I sold that bike, Kawasaki would never make another dime off of me. The bike to me was just terribly unreliable, but the good news is, it taught me to be mechanic. To get on with the rest of the story, a friend of mine was a rabid Kawasaki guy and still is. Even he though, went out and bought a new K2 and took me for a ride on it. No, it didn't have that rush of power delivery that the Kaw 500 had, but it was subtly quick. It was smooth and quiet with the rich tones of the then new to the modern world, 4 cyl. engine. Soon after, the 500 Kaw. made me walk for the last time and I bought the K3. I am still in love with that bike and it still resides in my garage, ready to ride when ever I am. Troubles I had with it, were a new tach required in the first few weeks. The exhaust system rusted out in the first year, but was replaced by warranty. I did buy new exhaust system again about 2 yrs. later and in 2000 I bought another new set after I got tired of looking at the Jardine slip-ons. Also, when the bike was 3 mos. old, the head gasket started to weep oil and was fixed under warranty, it is now weeping again after a long run on the interstate. But, the bike has almost 49,000 miles on it now, all put on by me. When that 900 Kaw. came out, in my area the 750 that ruled the road, had to step down. Still regarded as a good bike, it just wasn't a 903 Kaw. I don't personally know of anyone here that kept their Z1's for a really long time, but I can think of 2 other K3's in my area that are still owned by their original owners. One though has not moved in years, the other is ridden every summer. My Kawasaki friend, went and bought the first Z1 around my area and he is still heavy into Kawasaki's. True to my word, Kawasaki never made another dime off me. But Honda has and the K3 has shared garage space with other bikes over the years, most of them long gone now, except for the Goldwing that I got new as well.

[MRieck]

Want some more vintage Kawi articles to read?  Go here
http://kzrider.com/index.php?option=com_kunena&Itemid=116&func=view&catid=13&id=352699
I think the article you mentioned might already be in there.  If not, I know the original poster would love to see it.

Wow. Lots to read there.

[mrbreeze]

I had a 74 Z1 and a 77 LTD 1000 back in the 80's......both fun bikes with plenty of steam.They will run all over a stock Honda but overall.....I would say the Honda was more dependable and easy to work on. I say everyone should have one of each(like Gordon!!).

[lostmykeys]

 All I can say is that I miss my Z1.I sold it this April recouped my original investment and got two bikes on top of the deal.
 One of the bikes is badass F3 but it will never be a Z1.

[mrbreeze]

I totally miss both of my Kawis but would never give up my K5 to get one back.................

[scottly]

They will run all over a stock Honda

The key word here is "stock".

[seanbarney41]

They will run all over a stock Honda

The key word here is "stock".

and unfortunately, everything that can be done to an sohc, can be done to dohc...

[mrbreeze]

Having 1 or 3 of each would be cool 

[Jerry Rxman Griffin aka MuthaF'er]

Yeah but............. How would/does a 750 kitted to 900 run against a Z? That should be the real question.

[seanbarney41]

a stock Z?...or one kitted to 1340?...see what I'm sayin'

[HondaMan]

Yeah but............. How would/does a 750 kitted to 900 run against a Z? That should be the real question.

In the day when the Z was new (1973-74), and perhaps because the riders were also new to them (?), the 750K1/2 with .5mm oversize pistons, port cleanup and valve setup (polishing, with 3-angle valve seat and deshrouding of too-hasty castings), slightly opened 4-pipe exhaust, 17/52 gearing with Diamond  XL chain, 120 mainjets with clips at 3rd slot, X24ES-U plugs and +3 degrees spark advance with more spring tension on the advancers, and K1/2 cam advanced 3 degrees: the 750 beat them at the stoplights and dragstrips all around our shop. These 750s also beat the then-touted R90S BMW, 4 times the price of either the Kawi or the SOHC4.

The thing that has long puzzled me, and I don't know enough Kawi owners to ask of, is why so many of them abandoned their Z1 in favor of [something else] by about 1980. It seemed like the 900 just vanished overnight, then sort of reappeared again in the 1990s as reawakened critters. I know the KZ1000 displaced some of them, but was it worth the trade-up for 100cc? Don't know, myself.
 
Here in the Denver area, there are now more of them (Z1) than I ever remember seeing in the past 30+ years here.

[dave500]

the 750 wasnt too fat,the z1 was,and a little more complicated as well,they both look nice,they both were decent quality for the money,anyone remember how expensive was the new 900z1 compared to the honda?

[Retro Rocket]

The Z1 handled like sh1t, i had a couple of mates that had both 900's and the old Z1000 and i was always able to get the better of them in the twisties, that really annoyed them, my 750/4 had an old Venolia kit, the guy i got it off said it was an 850, went a lot better than stock....

[bwaller]

As Dave mentioned because of the wider Mikuni carb spacing they were a tad fatter through the middle, but the CB tank is wider at the back though...apples & oranges I suppose. Most riders would never really tax the handling of either bike, but the big Z had it's issues in that department.

I had a buddy with a 73 Z1, we were both eighteen & fearless!  In 73 my 750 was a production racer, had a few tricks, bored to 810, with a stock cam but hollowed 341's. It ran strong but couldn't hang with the stock Z1 under acceleration. However we did "have a go"one evening racing from one town to the next on mostly straight roads. It was a 15 mile WFO affair and he got away on acceleration, but my 810 had a tad more on top end and eventually reeled him back and beat him there. 

Just one blokes tale, and I realize how young & dumb we were, but what can I say, it was fun.

[Eydugstr]

Yeah but............. How would/does a 750 kitted to 900 run against a Z? That should be the real question.

That's my thoughts exactly.  Not doubting Hondaman a bit, if anyone can make a Zed killer out of CB750 it'd be you, HM - but after hearing about the 900-1000cc big bore upgrades for the CB's I've often wondered if the Zed would still be a better builder's bike, because of the DOHC's (better breathing).

Another question I've wondered about when it comes to the Z1's....Did they improve the quality compared to the Triples?  I have an H2, and can say from personal knowledge that quailty wise the Honda blows it out of the water.  Is the same true for the Zed?

[lucky]

I have owned both.  I have no good memories of the Kaw except that it was fast and had terrible handling; it was the only motorcycle I have ever sold that I was very glad to get rid of.  Of course my memory of it includes a street accident within 10 minutes of buying the damnedable thing that cost me 6 broken bones and considerable loss of blood.

Sounds horrible!!

[HondaMan]

Yeah but............. How would/does a 750 kitted to 900 run against a Z? That should be the real question.

That's my thoughts exactly.  Not doubting Hondaman a bit, if anyone can make a Zed killer out of CB750 it'd be you, HM - but after hearing about the 900-1000cc big bore upgrades for the CB's I've often wondered if the Zed would still be a better builder's bike, because of the DOHC's (better breathing).

Another question I've wondered about when it comes to the Z1's....Did they improve the quality compared to the Triples?  I have an H2, and can say from personal knowledge that quailty wise the Honda blows it out of the water.  Is the same true for the Zed?

The "Z" was a much better- built bike than the "H", by far. Those poor Blue Streaks...fast, but short-lived. They were redesigned into much better versions by the time they had points added instead of the ill-fated CDI, handling better, stopping better...did you know, the original Blue Streak frames offset the rear wheel 3/4" (19mm) to one side? I think it was the right side, don't remember which side, now. Nasty handling.

The "Z" was (is?) a sensation of its own, and provided many of us a lot of fun, either chasing it, beating it, racing it, or just playing with it. IMO, it's #2 in the "Bike History Book", right behind the CB750.

[Jeff.Saunders]

The Z1 engine is the 350 chevy V8 of the motorcycle world.  It's a tremendous step up from the Honda SOHC engine design.

Very, very different.
The Z1 cams run in replaceable bearings - pick up some debris in the oil on a SOHC engine, and you can trash your head - on the Z1 you replace the bearings without issue...
The Z1 does not have a primary chain - straight cut gears run directly from the crank to the clutch basket - while they whine a little, the power deliver is the best it could be.
The Z1 crank, and the rods in particular, are over-engineered massively.  You can run stock rods in Z1 engines that make over 300 hp - try that with stock SOHC rods - you need to replace the rods when doing even the smallest performance upgrades on the SOHC engine.

Back in the 70's I used to drag race my street Z1 - it was punched out to 1015cc, 10.5:1 pistons, 4-1 pipe, 29mm smoothbores - on a street tire, it would run 11.3 - 11.5 at 120mph all day - during the 2 years I ran that bike, I never needed to do any major work on the engine - I put over 30,000 miles on that engine AFTER it was bored out - when I sold the bike in early 1980, it had 50,000 very hard miles on it - well over 250 1/4 miles passes...  not once was I beaten by a SOHC Honda.  Back then, Brian Johnson (of top fuel motorcycle fame) ran a 810cc SOHC street bike - it never ran in the 11's.  There were several other people running SOHC's back then - but they were never a threat.

The Z1 handling is something you can easily improve.  Much of the handling issue is setting up the bike properly.  The Z1 is very nervous if you put the wrong tires on it.  THe rear shocks were not good - I changed to Koni shocks on my first Z1 and the handling improved massively.  I've owned a fair few Z1's over the years - and while a few have been pigs handling initially, going therough the bike carefully solves much of the issue.  You still have to respect the bike at speed.  I still have my turbocharged Z1 - 1200cc's and very fast.  That is the first bike I can honestly say I feel the frame flexing under serious load in 3rd gear - and that's with some frame bracing added - but then it's making somewhere between 130 and 150 hp for a frame designed for 80 hp.

[Bailgang]

A brother of mine had an H2 when I was a teen in the late 70's early 80's, my nephew owns it now as is almost done restoring it. I remember the bike having a power band that would scare the daylights out of you if you weren't ready for it. One time my brother hit the seat of it with some Armorall and took the bike out for a blast shortly afterwards, the seat was so slick that the bike literally shot out from underneath him when he gave it full throttle. 

[LesterPiglet]

The Z1 engine is the 350 chevy V8 of the motorcycle world.  It's a tremendous step up from the Honda SOHC engine design.

Very, very different.
The Z1 cams run in replaceable bearings - pick up some debris in the oil on a SOHC engine, and you can trash your head - on the Z1 you replace the bearings without issue...
The Z1 does not have a primary chain - straight cut gea....................

This is why I love this forum. Joined 2005, posts 166, and then what a great post. Thanks Jeff.

[seanbarney41]

....plenty more to thank Jeff for