Lash continues to increase...?

As said, the valve lash on a clients machine continues to increase and every couple months in to a season he comes in and sure enough we've had to use larger shims on more than one of the valves.

Whats the deal? We've checked compression/leak and quench/heights, bolt torques. Pulled head inspected seats and valves and guides. cams are true and bearings good, no increases in spec. Everything nice an clean and runs great, just gets louder till we replace shims...???

Myself and a couple other mechanics are lost on this one. Maybe we're just tired here, but I seriuosly cant find the reason for it.

Any suggestion???

Thanks.

This is one for Larry no doubt...

What was done to the head?
Valve job, new/old valves, new guides, new springs, retainers etc... or using 30 year old originals....

Make and model of bike involved, and any engine mods?

Good Fortune!

Obviously something is wearing somewhere. You will have to do some sleuthing and find out, where.
Not knowing the model we cant be specific.
As u know, usually the face and seats ware and the clearance shrinks.
Could the stems be getting shorter through ware?
or the shim or rocker?

Very strange.Either the springs are collapsing,or the retainer holes are getting bigger.That happened to a friends Ford Cleaveland engine.Then the retainer popped and we had to change the motor.

do you have the right retainers to go with the keepers? theres 2 differant styles on big kzs anywayyeah i meant to say valves to go with keepers folks! :S

What are the two different keeper retainer combos?

This keeper fits all the 7mm Kawasaki KZ valves 1973-1984 KZ900, KZ1000, J, GPz models. Order 16 for a complete set. This original Z1 900 Valves were square Keeper grooves, but all the aftermarket valves are radius keeper grooves.

Keepers

youre right jay,i meant valve and keeper combination theres 2 of them! :laugh:

When the head was taken apart, was the valve springs and buckets put back in the same cylinder....Or were they switched to another cylinder?

Kraz1 wrote:

...but all the aftermarket valves are radius keeper grooves.

Not true at all. There are several companies making the earlier Z1 style valves. We stock 2 different brands.
www.z1enterprises.com/SearchResult.aspx?...&KeyWords=z1%20valve
www.z1enterprises.com/detail.aspx?ID=321

As to the valve clearances INCREASING.

I've only seen this with engines burning oil - the valves/seats get a layer of carbon on them.

The only other thought is whether the clearances were checked with the engine cold both times. There is a fair variance in clearance depending on engine temperature. On one of my engines, I checked the clearances hot, then again multiple times as the engine gradually cooled down. The clearances changed several thou during the cooldown.

TeK9iNe wrote:

As said, the valve lash on a clients machine continues to increase and every couple months in to a season he comes in and sure enough we've had to use larger shims on more than one of the valves.

Whats the deal? We've checked compression/leak and quench/heights, bolt torques. Pulled head inspected seats and valves and guides. cams are true and bearings good, no increases in spec. Everything nice an clean and runs great, just gets louder till we replace shims...???

Myself and a couple other mechanics are lost on this one. Maybe we're just tired here, but I seriuosly cant find the reason for it.

Any suggestion???

Thanks.

What engine is this ?

What is the mileage between visits?

How is the bike ridden?

As someone pointed out, it sounds like a retainer issue.