a KZ design flaw (broken shifter spring) - sample size = 2

Hi Guys,

some of you may have read my posts re: broken shifter pedal spring on my KZ305 (1987)....

I first started the process of the repair (to learn the ropes) on my "dead" KZ400 (1978)....

anyway, while reassembling the KZ400 today, i more closing examined the shifter spring on this bike (as i had not taken the shifter arm out - did not see the need to)...

would you believe it!

the spring on this 1978 KZ400 is broken as well (same EXACT PLACE).... I'd never riden this bike (got it in Dec and it is in pretty bad shape)... I have to wodner if this KZ400 was "shelved" because of a clucth problem (i.e., broken spring)....

Are you talking about the big spring that loops over the external shift mechanism that returns it to its initial position? I have seen bunches of these broken on all models. They are essentially a bow-tie looking deal where there is one spring end providing the back to the middle position from both up and down and these single pieces of spring (not the loop) take all the pressure from a big boot so it isn't surprising that they would fatigue and break at that point. I have a couple broken ones up in the shop I think.

well, not so much a "big spring" (there is a really BIG ONE in the KZ400 - but not the KZ305; if i remember correctly), but it is a spring (not much wider in diameter than a quater) that goes around the shifter pedal "arm" prior to it being instered through the main portion of the engine...

curious....

your mentioned "big boot"...

i wonder... could "I" have caused it to break by shifting wrong or too "strongly"???

Is the spring you're refering to (ref# 92081C) the one I circled in the pic below?



If so, and even though it's fairly small in size, that's a fairly stout spring.
Is it possible that it's being broken in how you are removing it?

Post edited by: RetroRiceRocketRider, at: 2006/05/21 21:45

YUP!

that is the spring and...

NOPE, not being broken while trying to remove it, as...

never tried to remove it!

in the KZ305, the piece just feel out onto the floor when i opened the cover and...

on the the KZ400, the piece was loose inside the engine cover...

That is the spring I am talking about. The arms that fit the keeper tend to break off with age. I have seen this spring broken many times.

My 400 had the same problem.
I guess it is a design problem. I bet it is especially a problem on 400, because the 400 is used mostly as a beginer bike (its perfect for that) and beginners don't shift nicely (you have to keep the RPM's in the right place for the gear/speed)

Peter