Topic: Cam chain myth, true or false?

[HondaMan]

Mostly, the (jealous) rumor-mongers started this to slander the enormous success of the 750. Kawi KZ riders used to sneer at the Honda's "reliability problem", but the Kawis spend a LOT more time in the shop being repaired or freshened up in comparison. Suzy was a little better, but no one (except possibly the pre-1973 BMW R60) holds a candle to the 750 SOHC4 reliability, not even Honda's Gold Wing.

Ha ha, while I'm obviously a CB750 fan Mark, I'm struggling to believe that the Kawasaki KZ or Suzuki GS riders would be in any way jealous of CB750's.

I've owned both and done many thousands of miles on them, and I can't think of any "weak points" with their engines, and of course they were so successful on the road and at the track, that Kawasaki and Suzuki dominated the Sportsbike market for many years afterwards.

The truth is, by 1973, the mighty Z1 had eclipsed the CB750, and it took Honda many years to recover, in the showroom, and at the track. Cheers, Terry.

That's certainly true in the sales! That's why the "cheapening" (as I called it) of the 750 began in 1973, too. Honda wanted to keep the price the same so it was a bargain against the Kawis, so they pulled costs out of the bike to hold that 'line'.

But, many years later and looking back, even here in the States a Suzy GT750 or GS750 is a mighty rare sight. The Kawis were all but gone until Z1 Enterprises helped spark them back to life, but I see maybe 1 or 2 in a year's riding in these parts, while I see a CB750 in some form at least twice a week in commuter traffic or in the mountains, touring. I haven't seen anything but pictures of the water buffalo in years. That's why I think the way I do about the CB today.

[Terry in Australia]

Yep, that's a reasonable point Mark, of course Honda built over 500,000 CB750's over it's 9 year model run, compared with far fewer numbers for the Z1's over the four years they were manufactured, and Suzuki was certainly the underdog with it's quirky GT750 two stroke triple.

Interestingly, over here at least, a Z1 commands ridiculous resale value, and even the GT750 Suzy goes for a couple of thousand more than a CB750, probably due to it's rarity. I'm thinking about adding a GT750 to my motley collection next, I've owned a J and an "M", but the model I'd love to have is the "K", the first Japanese production bike with a twin disc front end. Eric's got a couple, but so far hasn't offered to send me one........... Cheers, Terry.    

[bryanj]

Main reason there are fewer Zed's about was the evil handling on the early ones putting a lot off, at least here in the UK. We had an insurance job where the bike and rider slide about 1 1/2 miles down a motorway (Freeway to you) in the early hours, main block was ok but the friction wore away the points cover, points plate, advancer unit and the bolt on casing behind that plus, of course, the bars and indicators etc

GT 750 was always popular but expensive, we built a racer in a special frame and after the engine mods, some of which I remember, would only do 6-7 miles to the UK gallon of fuel!!

[Bailgang]

I don't think it's jealousy but more so bragging rights when you get motorcycle enthusiasts in the same room reminiscing. I wish  I had a dollar for every time I heard a former or present cb750 owner say they never got beat by say an H2 Kaw or my other two older bros who both owned H2's and claim they never got beat period. It's amusing when all 3 of my older bros are together with each competing with each other over bragging rights, collectively they've owned big and small block supersport Nova's to V8 powered mid engined Yenko Corvairs and Norton Commandos to H2 Kaws and I swear that listening to them you'd think they had the fastest cars or bikes on the planet.

[Bailgang]

Main reason there are fewer Zed's about was the evil handling on the early ones putting a lot off, at least here in the UK.

You may have a point there because finding a Z1 for sale around here isn't all that hard but finding one that's in stock or reasonably stock config is hard to find and if you do spot one you better be prepared to spend some money to get it. Every single Z1 with the exception of maybe one that I've seen for sale around here has been converted to a full tilt drag bike.

[andrewk]

Main reason there are fewer Zed's about was the evil handling on the early ones putting a lot off, at least here in the UK.

You may have a point there because finding a Z1 for sale around here isn't all that hard but finding one that's in stock or reasonably stock config is hard to find and if you do spot one you better be prepared to spend some money to get it. Every single Z1 with the exception of maybe one that I've seen for sale around here has been converted to a full tilt drag bike.

That's the truth.  I spent a couple years courting a guy over a Z1, it was repainted, but in stockish configuration.  Someone else got the jump on it, and instantly doubled the price. :/  Having a Z would be cool, but for the money I can have a few nice Hondas.

[Gordon]

I don't think I've ever upshifted below 6k

I do, but only when I'm leaving for work at 6am, and because I actually like most of the people in our new neighborhood.  As soon as I'm out on the main road, though, it's time to clear out those combustion chambers!

Gordo, did you reinstall yer old baffles again!?

What do you mean by "reinstall"?   I was running with no baffles for the longest time, and then I finally got some stock baffles, but on the HM300 pipes they don't do much more than take the edge off.

[eigenvector]

I'll simply go ahead and believe what HondaMan is selling, because it sounds informed on actual case history rather than the anecdotes I rely on.

But I would believe the 550's throwing their camchains, I've had it happen twice.  I would like to think I'm being honest by saying that it's a consequence of poor maintenance and a lack of attention to detail  - but speaking as an engineer I really don't know what they were thinking by designing it that way.  It's easy for me to armchair quarterback them though.

[bryanj]

In all the years I have been working on them I have only seen two "Broken" camchains

(1) a CB500 Twin that had been rebuilt so i suspect the chain wwas not riveted right

(2) a CB250N (I think you only had the 400) where the camchain tensioner had been severly abused by a hamfisted owner

[Terry in Australia]

Main reason there are fewer Zed's about was the evil handling on the early ones putting a lot off, at least here in the UK. We had an insurance job where the bike and rider slide about 1 1/2 miles down a motorway (Freeway to you) in the early hours, main block was ok but the friction wore away the points cover, points plate, advancer unit and the bolt on casing behind that plus, of course, the bars and indicators etc

GT 750 was always popular but expensive, we built a racer in a special frame and after the engine mods, some of which I remember, would only do 6-7 miles to the UK gallon of fuel!!

The Z1's really weren't all that bad handlers, they weren't great, but the engines had too much power for the chassis. My guess as to why there are so few on the road (apart from the fact that they had such a short model run compared to the CB750) was that the engines were so popular for drag racing, speedway outfits, off road racing etc. Back then a 10 year old Z1 was worth next to nothing (much like any 10 year old sportsbike is now) so there was no interest in restoring them, so folks were tearing the engines out for racing and throwing the chassis away.

You're right about the "Water Bottle's" love for gas, I (riding a GT750M) raced a guy on a H2 for 140 miles in 1979 averaging well over 100 MPH, and we made 3 stops along the way, one so he could do a plug change (he had a pocket full of spark plugs in his old Army Greatcoat) and 2 gas stops each, at full song those old 2 strokes had the same fuel economy as a big block V8! Cheers, Terry.  

[ekpent]

Yep a lot of the big Sazook 4's like the mighty Z1 were used and abused a 1/4 mile at a time back in the day.

[HondaMan]

How about the KZ1000?
Around the US Midwest States, they were enormously popular with the police. They had a good-sized alternator, could idle all day long, and achieve 100+ MPH quickly as a pursuit bike. Today I STILL see them in Police service as speed trap rundown bikes. Here in the Denver metro area, all summer long you can see the BMW bikes with the guy who has the radar gun, and 3-4 pursuit bikes all lined up as you enter their 'traps' on the freeway. And it seems there is always at least 1 KZ1000 in the set.

How long did they make the mighty 1000?

[seanbarney41]

I really don't differentiate much between a Z1 and a KZ1000.  A KZ1000 is more the same as a Z1 than a K1 is to an F2.  KZ1000 has more power, better brakes, better frame and handling, even more bullet proof bottom end, just not all the vintage good looks, much like a cb750f.  KZ1000 was the same engine as z1 from 76-79, then the J model engine was same basic design but little interchanges with early engines well into the '80's.  KZ1000P (police model) was in production well into the 90's with the J engine.

[HondaMan]

I really don't differentiate much between a Z1 and a KZ1000.  A KZ1000 is more the same as a Z1 than a K1 is to an F2.  KZ1000 has more power, better brakes, better frame and handling, even more bullet proof bottom end, just not all the vintage good looks, much like a cb750f.  KZ1000 was the same engine as z1 from 76-79, then the J model engine was same basic design but little interchanges with early engines well into the '80's.  KZ1000P (police model) was in production well into the 90's with the J engine.

Ah, that explains all the chase bikes, then! They sure seem to be a good bike?

[seanbarney41]

I really don't differentiate much between a Z1 and a KZ1000.  A KZ1000 is more the same as a Z1 than a K1 is to an F2.  KZ1000 has more power, better brakes, better frame and handling, even more bullet proof bottom end, just not all the vintage good looks, much like a cb750f.  KZ1000 was the same engine as z1 from 76-79, then the J model engine was same basic design but little interchanges with early engines well into the '80's.  KZ1000P (police model) was in production well into the 90's with the J engine.

Ah, that explains all the chase bikes, then! They sure seem to be a good bike?

lots of guys touring on retired kz1000p's, I have even seen several streetfightered p's done over at KZRider.com with USD forks and monoshock rears, as the J motor makes close to 100hp with a big bore and cam swap

[scottly]

Regarding the KZ1000P, does anyone remember the TV show CHiPs?
Seriously, the cop versions were known for high-speed handling issues. I recall a cop getting killed when the bike went into a high-speed wobble during a pursuit in Bakersfield, CA. Kawasaki's research found the weight of the radio, mounted high and at the back of the bike was the main culprit, kind of the "tail wagging the dog".

[seanbarney41]

You know, just once, it would be nice to be able to talk about Kawasaki's on this forum, without someone bringing up the "legend of the dangerous handling Kawasaki's...those things will kill you if you even so much as have an unbalanced booger load between one nostril and the other!"  The only significant difference between Honda and Kawasaki's frame's is that one houses an engine that has enough power to get you in trouble.

[scottly]

Sorry, Sean, but it was a real event that happened in the early-mid '80's.

[seanbarney41]

Sorry, Sean, but it was a real event that happened in the early-mid '80's.

I believe you... but anytime you give someone 130plus mph capabilities on a motorcycle, some butterfly in Brazil is bound to flap it's wings causing a bad thing to happen.  I think I read somewhere the KZ1000P was the most widely used police bike ever used and I doubt that would have been the case had this been a long term, unsolveable issue.  The cops around my neck of the woods got Road Kings, so you know they are snug as a bug in a rug.

[scottly]

IIRC, the cop was going about 90 mph when he lost control. Again, it was the rearward weight distribution of the added police hardware that caused the instability, not the design of the original bike, at least according to Kawasaki. I'd feel safer on a Kawi than a Road King: I knew one guy with a 3" shorter leg, and another that lost 3 fingers from them.  

[seanbarney41]

No way dude...Road King is wayyy safer because any dangerous parts like heavy radios will fall off before any real harm can be done.    I have actually ridden a police model Road King, and to be honest, it was the smoothest, fastest, most stable farm implement I have ever ridden.

[scottly]

Farm implements tend to be most stable at speeds below 15 MPH. We're getting a bit OT.

[HondaMan]

IIRC, the cop was going about 90 mph when he lost control. Again, it was the rearward weight distribution of the added police hardware that caused the instability, not the design of the original bike, at least according to Kawasaki. 

I heard about that one, too. The CB750P model was blamed for a similar situation: here's what had quite a bit to do with it all, in the end:

The high and rearward weight accessory frames were sometimes anchored only on the tail of the frame (read: shock mounts) with possibly a 'stabilizing strap' to the rear fender, in the case of the high-mount radio (or CB750 rear police lights pack). Since the fender on both bikes is merely bolted sheet metal through a plastic inner rear fender piece, the plastic inner would crack and a chunk or two would fall out, leaving quite a bit of slack in the mount. On the 750, this would almost immediately cause weaving (think: Triple A luggage rack systems, famous for this) by input to the steering that you can simulate by centerstanding the bike, then grabbing the tail light and wiggle back & forth. If the tires had a slight flat worn on them, they fanned the stops.

Inner rear fenders with steel grommets bored and pressed through instead of plastic, and heavy wire stiffeners mounted or welded inside the rear fenders solved it handily on both bikes (I only did one Z1, though). With the 750, I solved it (like with my Krauser luggage) by hard-mounting the rear fender and taillight, then cross-strapping the luggage racks to the license plate bracket, using a thick aluminum angle bar to which the license plate gets attached (much stronger than taillight metals). As soon as I did this in 1972, the bike (mine) was 1-hand straight at 100% throttle in top gear in any crosswind with any luggage load, so we did it to the police Beemers, the wobbly Suzy waterbikes with luggage, and any other customer who asked.

After that, I often carried payloads in excess of 600 lbs. (my first wife was unbelievable about packing stuff...) as fast as my Honda would go, across the West. It never wiggled!

[Terry in Australia]

Yeah, you really couldn't blame Honda or Kawasaki for "add ons" that various police forces had fitted to bikes that weren't designed with them in mind.

It's not hard to make a bike that previously handled well, handle poorly. Suzuki added a very pretty "Bikini" fairing to the GS1000 (that was considered the best handling Jap bike of the 1970's) when they released the GS1000S "Wes Cooley Replica" which caused "Tank Slappers" at high speed, and most owners took them off to improve handling.

I took the full fairing off my 1979 BMW R100RS and replaced it with the R90S bikini fairing one summer and discovered that with the factory panniers fitted it wobbled and wallowed all over the road at speeds in excess of 90 MPH. If I took the panniers off there were no problems, but with them on, it was deadly. I took them off.

On top of that, the tyres and suspension of the era were marginal, at best. The original Bridgestone tyres on my shiny new CB750F0 were just rubbish, and I replaced them with Avons in the first 3 months of ownership after almost dropping the bike on wet roads every time it rained. Kawasaki, like Honda, used the same rear shockers on just about every model bike they made, the springs were too hard, and the damping almost non existent, so coupled with crappy tyres and soggy forks, the big Kawasaki's were not for the faint of heart.

I haven't ridden a Police model Road King, the only one I've ridden was a 2003 model in full tourer mode with a fork mounted fairing and bags, and it actually felt very planted at 100 MPH. I'd own one. Cheers, Terry.

[01Thomas]

Soooo... getting back to camchains: is the current stock Honda CB750 camchain from an authorised Honda dealer significantly worse than a good quality aftermarket camchain, say from DID?
The bike will be used for spirited street riding (if I want to go really fast I have a Yam YZF750SP).

regards
Thomas