Z1 Cam Chain Idler Gear Bearings

  • JT-NZ
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Z1 Cam Chain Idler Gear Bearings

Today 21:01
#922368
Is it possible to change out the roller bearings in the two cam chain idler gears ? Mine feel a bit rough when I spin them.
Are the roller bearings an odd size (I'm used to Honda's which often have odd ball bearings sizes) ?

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Re: Z1 Cam Chain Idler Gear Bearings

Today 02:18 - Today 02:59
#922370
The bearings are imperial.
They are 7/16" id x 5/8" od and 1/2" inch wide.
Common codes for them amongst others are BA78ZOH , SCE78 and J78 but beware of cheap options which have fewer needle rollers than the genuine ones.
I have found that INA brand have the correct amount of rollers. 
 
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Last edit: Today 02:59 by zed1015.
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Re: Z1 Cam Chain Idler Gear Bearings

Today 02:19
#922371
I know it's possible and the "Drawn Cup" bearings are available somewhere but I've never done it. Thinking bearings are 11mm ID, 16mm OD and 13mm length. One of the fella's here does it, perhaps he'll chime in. Take note of condition of your rubber damper vulcanized between bearing holder collar and sprocket first. This is the usual failure point allowing the sprocket to roam free of bearing holder steel collar. Have fun!
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Re: Z1 Cam Chain Idler Gear Bearings

Today 02:34
#922372
As z1015 says, he, myself and others have done these and modified them to solid centres also.
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Re: Z1 Cam Chain Idler Gear Bearings

Today 04:25
#922377
As Clay stated, the failure point is usually the rubber damper.  Best solution is to convert to solid as zed and others have done or just buy Liska solid billet type sprockets.  KZZone, Z1enterprises, and others sell them.
Doesn't make much sense to depend on 50 year old rubber that's been subjected to all those heat cycles...

Scotty

1974 Z1A
Yoshimura 987, 10.25:1
welded Z1 crank
Andrews 1X Cams
Delkevic 4 into 1
Superbike bars
530 conversion
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Re: Z1 Cam Chain Idler Gear Bearings

Today 05:18
#922380
Perfect representation of failure sf4t7!! I have bags of the same, just can't seem to throw stuff away. I have noted over the years the early "peanut" camchained KZ650's used the same idler gears but had a different Kawasaki part number? All dimensions identical to the Z1/KZ ones but had a different "pin count" of needles in drawn bearing. Z1 had 14 and KZ650 had 16. What do YOU get for a set of 3 solid rebuilt idlers Kevski? Or are you selling them? Seems you're in the states so shipping would be soo much easier. Also, not mentioned NT-NZ, check for run-out of sprocket. Mount it, spin it and watch toothed behavior. Run true or does sprocket wander back and forth?  
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Re: Z1 Cam Chain Idler Gear Bearings

Today 07:04 - Today 07:05
#922392
Yeah, took those out of my hotrod Z1 motor a year and a half ago.  Could explain why the timing was a little different each time I checked it, and every once in a while the motor seemed sluggish. Replaced all the sprockets and idlers with APE (liska) billet parts and it goes like a rocket again.   
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Scotty

1974 Z1A
Yoshimura 987, 10.25:1
welded Z1 crank
Andrews 1X Cams
Delkevic 4 into 1
Superbike bars
530 conversion
Last edit: Today 07:05 by sf4t7.
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Re: Z1 Cam Chain Idler Gear Bearings

Today 08:02
#922398
asphalt900 wrote:
Perfect representation of failure sf4t7!! I have bags of the same, just can't seem to throw stuff away. I have noted over the years the early "peanut" camchained KZ650's used the same idler gears but had a different Kawasaki part number? All dimensions identical to the Z1/KZ ones but had a different "pin count" of needles in drawn bearing. Z1 had 14 and KZ650 had 16. What do YOU get for a set of 3 solid rebuilt idlers Kevski? Or are you selling them? Seems you're in the states so shipping would be soo much easier. Also, not mentioned NT-NZ, check for run-out of sprocket. Mount it, spin it and watch toothed behavior. Run true or does sprocket wander back and forth?  


I have never sold them, just given the occasional set away, I don’t have much time for  it now,  not sure it would be a viable business.

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