valve timing

[alinus65]

hi,

I removed both cam shaft because I was not able to take 2 shims even with the special tool.
Today I have assemble everything following this instruction:







my bike is z1b and there are some differences:







Do you have instruction for camshafts installation in simple words?

One more problem.
By mistake I turned by hand the cranshaft with the special purpose tool installed. Do you think I damage the valve?
The shim on that valve was 280 and clearance 0. I put shim 270 and now clearance is 0,20. Is it a sign that valve is damage.

Sorry for my English...

Ciao

[z1bman]

if you look at the end of each camshaft you will see a section cut out from from the cam. with the engine set to top dead centre on 1&4 cylinder half of this cut out section should be below the cylinder head mating surface when the valve timing is correct. inlet cam cut out should be facing towards the rear & the exhaust cam cut out should be facing foward. as for the valve being bent / damaged make sure your valve timing is correct then do a compression test

[chrisNI]

Unfortunately the valves can bend pretty easily, don't want to worry you but if a clearance changed it doesn't sound good... Put the same 280 back in and double check in case the 270 is worn.

Been there... Good luck

[z1bman]

it would be very unlikely for a shim to wear as they are hardened

[zed1015]

Shim wear is common. They end up dished and thinner towards the centre . In extreme cases they can fracture if removed and refitted the other way up.

[alinus65]

Thanks for your valuable suggestions.
Yesterday I managed to install properly (I believe) the cam shafts.

I have checked the clearance and I am afraid that one valve has bent.
I am talking about intake valve cylinder 4.
Before it was clearance zero with 280 shim.
I put 270 and now clearance is 0.45. This is the warning of valve bent .
What do you suggest in such case.
My plan is to put 305 shim fire the bike and check compression.
What do you think?

I am really pissed off. Bike was running fine except for a bit of hesitation at low rpm in acceleration.
Winter is time to make damages. Better ride the bike in summer

Ciao

[z1bman]

just leave your shims as they are do not replace the shim for a 305 as this will remove all the clearance from the valve . for a good compression reading you need clearance in the the valves

[alinus65]

With 305 I should have 0.1 clearance. Am I right?

Ciao

[chrisu]

if you've bent the valve then it'll need to be replaced - head off job i'm afraid.

no real alternative.

[alinus65]

if you've bent the valve then it'll need to be replaced - head off job i'm afraid.

no real alternative.

Do you believe that such clearance increase means valve bent? We are talking about 0.30 clearance increase.
Which are the risk to fire the bike and test compression?
Thanks

[z1bman]

just run the bike as it is for the compression test it will just be a bit noisy but wont do any harm

[chrisu]

if you've bent the valve then it'll need to be replaced - head off job i'm afraid.

no real alternative.

Do you believe that such clearance increase means valve bent? We are talking about 0.30 clearance increase.
Which are the risk to fire the bike and test compression?
Thanks

a sudden increase in valve clearance like that then typically yes.

As Z1Bman says - run it if you like - a compression test will show that cylinder way down if the valve is bent.

[alinus65]

At the end I found a very good mechanic.
6 valves was bent.
Work has been done properly.
Carbs have been cleaned as well.
Now bike is smooth like silk.

[wilsonsjw11]

It's good you got there in the end.
Now enjoy the bike
Regards
Steve