Topic: Why so complicated?.....

[mutt]

I just reassembeled the throttle shafts etc on my friends CB500......Im curious if anyone really knows why in the WORLD the rack mechanism & the carb slide linkage inside the carbs are SO damn complicated? Never seen the like.
of course, i dont mess around with many 4 bangers, but I ran a Tri Trident for years- 3 slide carbs, linkage dead simple. And ive worked on a lot of twins, brit & oriental: ditto.
Do the Japanese pay homage to Rube Goldberg a  regular thing??? This is truly nuts, for no apparent reason.....

[HavocTurbo]

I believe it has everything to do with synchronization.

Back in the day the Japanese were so cold in their engineering that if something didn't work, they didn't modify, the started completely over.

I'm of the firm belief that the complicated mechanism is a product of that coldness regarding carb synchronization.

[754]

heh heh, it could make you cranky.. especially if you went to all that work ..for nothing..

[HondaMan]

To add to the strangeness: the 500/550 linkage geometry actually causes the famous "flat spot" toward midrange that these bikes have always displayed. It's not in the spark curve or carb's mix: it's always been the linkage. I used to have a trick (it's in Thoughts of Hondaman, probably) where I added some solder in the pull groove, right about midrange, to improve the mechanical leverage a little: some riders swore I'd done something magic to their engines as a result. It would stay for a while, until the solder flattened: about as long as the points lasted, too. So, I got a lot of "performance tuneups" for the 500 out of my shop this way, for an extra $5 (in 1970s dollars!). I guess that made me a cheat... 

Racers used to sub in the (very expensive) Yosh 1/4 turn throttles on the track 500, then go out and kick some butt with them. The fizz is in those engines, just has to be coaxed to come out & play... 

[mutt]

HAR! Thanks for the replies, chaps....and the midrange flat spot heads up....save me goin nuts trying to winkle it out, Ill just tell her its a "feature".
I got the needles all set one groove rich, and the thing is ready to go back on the engine. Plus Aunt Flo, the RollerDerby Queen who own it, just dropped off a 4 pot mercury synchronizer....gotta make some threaded tubes for the manifolds, & see what happens....
Being an old Brit bike hand, its interesting to work on the machines that put the brit cycle industry pretty much out of business. Ill take brit simplicity & handling any day, but I find a lot to like about these early Nipponese  multis.
Clever devils .......they took the Brit motorcycle industry like they took Singapore.....

[HondaMan]

HAR! Thanks for the replies, chaps....and the midrange flat spot heads up....save me goin nuts trying to winkle it out, Ill just tell her its a "feature".
I got the needles all set one groove rich, and the thing is ready to go back on the engine. Plus Aunt Flo, the RollerDerby Queen who own it, just dropped off a 4 pot mercury synchronizer....gotta make some threaded tubes for the manifolds, & see what happens....
Being an old Brit bike hand, its interesting to work on the machines that put the brit cycle industry pretty much out of business. Ill take brit simplicity & handling any day, but I find a lot to like about these early Nipponese  multis.
Clever devils .......they took the Brit motorcycle industry like they took Singapore.....

For those carb sync holes: if you don't have the metric threads available, tyr the 10-32 variety: they are very close, and work OK.

[mutt]

 tyr the 10-32 variety: they are very close, and work OK.
%hx, Hondaman, that simplifies things. ill pick up some brass tube at the hobby store.....
After she piles on some miles & its time to tweak the points, Im gonna have her invest in your transistor switch. I like the concept, & sheel like having the points not need near as often tweaking....do you keep the condensors in place?

[HondaMan]

tyr the 10-32 variety: they are very close, and work OK.
%hx, Hondaman, that simplifies things. ill pick up some brass tube at the hobby store.....
After she piles on some miles & its time to tweak the points, Im gonna have her invest in your transistor switch. I like the concept, & sheel like having the points not need near as often tweaking....do you keep the condensors in place?

Yep, keep the condensors, especially if the points are not new. It helps clean up the opening "break" point.