puch za50 shift shudder

been getting some shift shudder in the rear wheel on my za50 (ported treats reed, points, sidebleed, 14 delorto, flipped stock clutch). it shifts solid 90% of the time but on occasion it lags and shudders the rear wheel. anyone ever experienced this? btm end is rebuilt and has new pucks, fresh fluid. engine runs smooth, pulls hard

also what clutch spring combos are you guys running? my takeoff needs more slip. i have red green and yellow springs to play with.

Re: puch za50 shift shudder

Yeah i just dealt with this, started shuddering and i couldn't find anything wrong... long story short I probably did another 300 or so miles after the shudder started and it grenaded my whole fuckin' tranny.


The one-way clutch outer housing cracked, causing the rollers to jam. The shuddering you feel is the rollers being un-stuck when the second gear clutch catches. Basically the first and second gears are working against each other because the one-way clutch is stuck locked up.

Eventually the cracks will get so bad that the rollers will just straight up jam solid, it will tear up or break the clutches or eventually put so much force into the first gear gearset that the teeth will break and get chewed off. Also it makes the reverse thread nut (center of 1-way bearing) tighten itself on insane-o tight.

In order to get the motor apart i had to get that nut completely glowing red hot with an oxy torch 3 times, hitting it with an impact wrench. Destroying/ruining the temper on the countershaft in the process.

Pretty much the whole transmission is gone from me ignoring the shudder!

Re: puch za50 shift shudder

Brad William /

What fluid? Try something else first before taking things apart? A simple option to start with anyway. Ive been very pleased with John Deere "hy-gard" xmission fluid.

Re: puch za50 shift shudder

having a loose nut on the end of the clutches or having too much play on the shimming on the clutch drum will also cause vibration that could be considered 'shudder' but i'm assuming when you say 'found nothing wrong' you mena that you checked all that stuff already.

the crack in the 1-way clutch is tough to find because its behind the sheet metal cover thingy and if you don't specifically pry that off and check you would never bother to open it up that far.

Re: puch za50 shift shudder


i have no experience modding ZA clutch springs but from my experience with tomos, having a higher shift point really accelerates the wear of the internal components.

Re: puch za50 shift shudder

All za clutches act different, I would gamble and find another set. Leave yours how they are as a back up.

Re: puch za50 shift shudder

Probably Fred /

Blip shift your bike, many times the shutter is caused by the free movement between the first and second gear clutches on the spline of the crank and they crook a little bit,

Space between clutches supposed to be a free moving a little or it doesn’t have to if you want to put shims in there (per ED Mopen? Old thread) but I have a bike or two that shutter a bit and run fine for years but most times I blip shift especially on my hi power Gila and polini kitted bikes And it keeps spline wear on clutches and crank to a minimum

but the more the clutches wear on the spline of the crank or the more the crank spline wears is out the more shutter you will have,

Re: puch za50 shift shudder

Blaine- The artist formerly known as Plumber Crack "(OFMC)" /

1st gear clutch is splined and is to be fastened tight to the crankshaft with the big nut. 2nd gear clutch isn’t splined to the crankshaft.

The shudder is most likely from the sprag clutch like graham has pointed out. Grip n slip, repeat rapidly. I’d carefully inspect every part of it closely.

Re: puch za50 shift shudder

just sayin'

i had that above motor apart 3 times and checked all the shims, tolerance, everything, couldn't find any problems so i said 'eh... normal ZA wierdness' then all of a sudden it cracked that clutch the rest of the way and ate itself alive in a 15 mile ride home from work.

i can usually hear/feel the change when things wear and loosen up, engine braking/decel you'll get a little different sound as the gear mesh changes, means its time to open up and check your shims.

using the 10w40 motorcycle oil, my za's dont shudder like the way a lot of A35's tend to. not sure exactly what you guys mean by shudder. but yeah i do blip shifts most of the time.

Re: puch za50 shift shudder

Probably Fred /

> Blaine- The artist formerly known as Plumber Crack "(OFMC)" Wrote:

> -------------------------------------------------------

> 1st gear clutch is splined and is to be fastened tight to the crankshaft

> with the big nut. 2nd gear clutch isn’t splined to the crankshaft.

Correct it’s not but it’s free moving and there’s play between two clutches

On a brand new engine you can wiggle it

You also can have shutter on output shaft if it goes in and out

Re: puch za50 shift shudder

Probably Fred /

What I’m saying is you could have shutter when it changes from 1st to 2nd gear and it could be nothing or it could mean something but if everything checks out fine just blip shift or back off a bit when it does it,

It seems like everybody here wants to have a sprint bike to drag race, if it’s a daily driver don’t drag race your bike from stop sign to stop sign unless you want to fix it all the time! (Though I sprint most times ha ha)

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