Design Disadvantages of the CB1100

[calamarichris_imp]

Everything designed by the hand of man has its advantages and disadvantages. As PeeWee Herman says, "Everyone I know in life has a big but(t)...":
~Harleys sound great and you never have to adjust the valves, BUT they're slow, inefficient, and the rear cylinder does not get as much cooling air as the front. (That, and you have to ride everywhere with a serious scowl of determination on your face, as if you are on your way to commit your third-strike felony.)
~Crotch-rockets are light & fast, but the cylinders are bored into the top half of the crankcase (disposabike) and being stuck behind an RV on a twisty road sucks even worse when you're on one of them.
~Vertical Twins (one piston goes up while the other goes down) can rev higher and are generally more efficient overall, but they get lumpy and weak at low rpm.
~Parallel twins (both pistons rise & fall together) are terrific at lower rpm and have a sweet, balanced sound, but they create a pressure maelstrom in the crankcase which inhibits higher rpm power.

So what are some of the advantages and disadvantages of the CB11's engine? Not interested in the smile-on-your-face while riding on a sunny day advantages. Every design has its disadvantages, what are the CB11's?
Heavy weight?
Plastic bits?
Throttle governor?
Less cooling air for #2 & 3 cylinders? (Are they jetted identically with #1 & 4, or richer/cooler?)

[the Ferret]

Well a disadvantage would have to be the width and weight of the engine. It a big mill. It doesn't produce a lot of horsepower or torque relatively speaking, although it has plenty of both for it's intended purpose.

It's frame is basic and heavy.

It doesn't have perfect primary or secondary balance so it does produce some vibration, particularly at higher rpms, but compared to singles, most twins, or triples it's very smooth.

It is so under stressed that it should run virtually forever.

But from a purely personal observation, it is a beautiful power plant, and motorcycle, and it's whole is greater than the sum of it's parts. It is a very satisfying motorcycle to ride and to look at.

[Rolls_imp]

Con: Valves require regular checking and possible adjustment. Would've preferred the proven and dead reliable hydraulic system that served so well in many Honda Nighthawks. Redline is under 10,000 rpm, so it certainly technically feasible.

Pro: Pretty damn decent fuel economy on regular gas for an 1140cc 4-cyl pulling 540 lbs.

[calamarichris_imp]

I'm actually a fan of the robustness and quiet running of the shim-under bucket design, and don't mind going in every 7500 miles or so, to make sure everything's happy in there, but to each his own. What is the valve adjustment interval on the CB11?

What kind of MPG are you pulling down?

Full disclosure: I do not yet own one, but am giving serious thought to trading in my EX50o dog-taxi for one. (It's not my only bike, just the one I'm thinking of trading in.)

[the Ferret]

8000 on the valve adjustments

50 plus mpg as high as 56 mpg, lowest has been 48 on first tank

[calamarichris_imp]

8000's not too bad. I presume an adjustment means lifting the cams?

If any of you guys are thinking of adjusting your own valves for the first time, it's a neat process. [url=http://www.calamarichris.com/zx9r/valveadj1.htm]Here's my little online primer for adjusting valves on Kawasaki's mighty ZX9R. (clicky) You'll still want to get the Honda Factory manual before tackling the job on your CB's, but it gives you an idea.
One advantage to this bike is you don't have to drain any coolant, disconnect any radiators, or worry about getting any little O-rings on the coolant plumbing misaligned. Ought to save at least an hour on the job.

Just made me think of another example of advantage/disadvantage:

Kawasakis are known for having comparatively steep cams, which mean excellent top-end power. But those tall cams require stiff valve springs to avoid valve float at higher rpm, which means more valve seat & seal wear. If you stay on top of the maintenance, they still do pretty well.
There used to be a joke going around about Kawasakis when I bought that 9R 12 years ago:
"What do you call a Kawasaki with a quiet top end?"
"A two-stroke."

My old 9R does sound a little clattery when cold, but I've been more than meticulous with the maintenance over the years and she still purrs like a kitten when warm, (and still has a terrifyingly brutal hit at 9000rpm that still scares me on public roads.)

[the Ferret]

Good night..just read all 9 pages of your valve adj procedure. Jeezalou that's complicated. Would have taken another 9 pages to put it back together I assume.

That is why hydraulic valves make a lot of sense.

[calamarichris_imp]

I'm a little more thorough than your average dealership tech. If you do a good job, it ain't gonna be finished in 3 hours, like they charge you for.
I've drunken with a few techs who don't even bother with a torque wrench. Even if you pay the dealership $90 an hour and tip him well, that guy with the facial piercings still ain't gonna put the love & Q-tips into your baby that you would.

Hydraulic valves have more working parts, and are therefore more prone to breakage & wear over the long haul. Yeah it's a lot of work, but there's something hugely satisfying about shaking hands with the magic genie inside your engine that magically thrusts you hundreds of feet per second through our thick, gooey atmosphere. (I'm also a cyclist, so I have an appreciation for this magic.) Do you trust a system over the long haul, or do you trust yourself?

Well a disadvantage would have to be the width and weight of the engine. It a big mill. It doesn't produce a lot of horsepower or torque relatively speaking, although it has plenty of both for it's intended purpose.

It's frame is basic and heavy.

It doesn't have perfect primary or secondary balance so it does produce some vibration, particularly at higher rpms, but compared to singles, most twins, or triples it's very smooth.

It is so under stressed that it should run virtually forever.

But from a purely personal observation, it is a beautiful power plant, and motorcycle, and it's whole is greater than the sum of it's parts. It is a very satisfying motorcycle to ride and to look at.

I said NO SMILE ON YOUR FACE/sunny day sentimentality, yo!

Pretty hard to do understressed without going big & heavy. That's an acceptable trade compared to lightweight and no power, IMO.

I'm surprised it has any vibration. I-4's are supposed to be basically balanced. My 9R doesn't have any balance shafts or counterbalancers, and that thing (to borrow a Ducatisti-ism) has all the character of an electric motor. (A 130hp electric motor.) I chuckle at all these Yamaha I4's that have unbalanced engines, so they sound better, like Rossi's GP bike. But there's no motorcycle engine in the world as efficient as a pre-Rossi/V5, balanced inline-4.
If I'm wrong, tell me which layout is more efficient and why.

Vibration? Really? What did you ride before you got your CB?

[Randy B]

The actually engineered in the vibration to harken back to the old days when balancing an engine (properly) was totally labor intensive and would triple the cost of the bike if done correctly.
Something about changing the cam spec somehow, but I can't remember the specifics and I'm too lazy at this very moment in time to look it up.

[calamarichris_imp]

So Honda took some QC shortcuts to make the bike more authentically retro? That's pretty discouraging, but I appreciate your candor. Let me know when the laziness abates and you've got some links.