KZ900 valve shims Machining

Nessism post=908255 userid=14026 I look for a used OEM shim, and only use K&L if the size isn't available otherwise.

   Weren't there other vendors selling shims too? How does one discern K&L from other vendors & OEM?  Seems too, that Mama Kaw changed their shim marking protocol some time during Z1 production.

Good Ridin'
slmjim & Z1BEBE

Kaw-boy 900 post=908260 userid=81101

There is 3 other pages of engine parts...piston rings, rollers, gaskets added.
This bike was also totaly restoted  like a show room bike ! and now...Pristine

I am guessing this is the bill for all the previous work done on the bike as there are things like "coat tank" on there plus I see 53.5 hrs service at $80/hr.
It does not take 53 hours to rebuild a Z1 engine, if it does there must have been two guys working on it! I am always suspect of hand written bills on unprofessional letterhead.

The price I mentioned was for a 6 mm overbore and porting pounds of aluminum out of the head.

As you stated, that wasn't a bill you had to pay.  Unfortunately now you'll be spending time and money to fix the questionable work done, hopefully it won't be anywhere near the same amount, I'm guessing you can do most of the work yourself.  But when you're done you'll have a cool, sweet running KZ900.

@ Injected: Concerning the labour time, I could possibely include the engine and forks polishing, installation of supplied parts from owner, new spokes on rims, paint ??

I don't know much about the bike history as the previous owner had it for one year only and he mentioned that he hadn't ride it much. The restoration was done two years ago, before he got it.

@  sf4t7 : I'm thinking of bringing the head to a machine shop specializing in high-performance motorcycle head. They are specialised in HD drag racing, Ducati and metric bikes, near montreal.




 

Taking the head to a reputable shop that has experience with these old beasts might be the best choice at this point. Somebody with good skills and much experience will be able to spot potential problem spots much more quickly and certainly than a whole bushel of amateurs. When you get it back and install it, you can move forward with confidence that you will have no problems from that quarter.

This whole scenario is an indication that you should perform all the routine maintenance items with extra care and vigilance.

Thanks Texas KZ,
You read my mind   I want do do it right and no worries !. I've read too many story (lot worst than mine) One guy even ground the sterm in place with a grinder....that a nightmare LOL

Here is the machine shop: I dont know that place yet but they have prouven results and solid reputation aurond here.
jprecision.com/metric/

Good God Injected, of course it takes that minimal amount of time to restore an engine if not more!! What/how do You do Your engines that takes less time?? I see lumps of disrepair everyday, an easy complete 8hr day just cleaning-up a crappy carcass from removal. And that is just blasting the initial crap off. You apparently don't do restorations of the upper crust/drawer. Takes me 5 hours to properly do just a cylinder block and head. Gotta change media along the way, sand to glass, then the real work begins.    

asphalt900 wrote:

Good God Injected, of course it takes that minimal amount of time to restore an engine if not more!! What/how do You do Your engines that takes less time?? I see lumps of disrepair everyday, an easy complete 8hr day just cleaning-up a crappy carcass from removal. And that is just blasting the initial crap off. You apparently don't do restorations of the upper crust/drawer. Takes me 5 hours to properly do just a cylinder block and head. Gotta change media along the way, sand to glass, then the real work begins.    
 

I guess I should have specified building the engine with all the finished parts at hand. Your right, I don't do "restorations", all of the bikes I have redone are just lowly riders.

The machine shop contacted does not do the final valve ajutments.  They asked to bring the head and valves without springs. They need the actual valves gaps and shims installed.
Valves stems will be reduded so normal shims can be install. 

My concern is with the actual shims machined at 1.5 to 1.7 mm and 2 x thight valves at .038 mm / .0015'', So how much stem can be reduce ? (Kawa spec is:  be sure to leave .16'' / 4.1 mm)

 Do yourself a favor, if the machine shop does not know about these engines and getting the valves correct buy one of these from APE and let them use it . It's a gage to get the valve in the correct range of shims about the middle. It has a step and by placing it it the cavity without spring seats you can tell right away. if its anywhere between the lower step and top you should be within range. 

Where are you located. If you'r on the West Coast Schuman Motorworks will do a good job and he will set the height to where you want them. Otherwise he will get you in the 300 range.




 

Thanks Cra-z1, 

I'm on east cost Canada, Montreal. 

This is the way to go Hopefully there is anought meat around the bone ! Will see tomorrow when the head removed.

If not, APE has insert seats but it's not cheap to get installed. app. $50 UDS plus refacing.

Tipping the valves is the tried and true method to increase shim size.  In extreme cases, where the tipping causes the spring retainer keepers to stick up above the tip of the valve, the retainers themselves can be shaved.  Or, as Steve said, get oversize valves and start over.

EDIT: Jay from APE mentioned the "shave the retainer" trick here before.  He said that they sometimes do that for police bike heads, which have accumulated a lot of abuse.  


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