Valve trouble

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24 Sep 2006 20:12 #79338 by Prune1
Valve trouble was created by Prune1
I hope I did not screw up my motor I have just built up. I have a 76 900 and I put a 1015 block bored to 1045 on her. Sent the head out to get new guides and milled. $$. Shimed the valves. Put everything back together with a new cam chain. Set the timing as noted by my manual. Began to cycle the motor by hand and heard a loud pop. I think there might have been a kink in the cam chain down by the crank, causing the timing to jump. Im pretty sure the valves are bent, my question is how much other damage has been done to the head/guides? Can I replace the bent valves and try this all over again?

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  • wireman
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24 Sep 2006 20:20 #79342 by wireman
Replied by wireman on topic Valve trouble
well check your timing marks and make sure chain is adjusted right.and try turning it over by hand again and see what happens,if the valves are already bent you have nothing to lose.if it turns over without going thump:S try a compression test before pulling it back apart,if its real low you know what to do.;)

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24 Sep 2006 20:29 #79345 by Prune1
Replied by Prune1 on topic Valve trouble
Yes, forgot to say I checked the compression. Nothing on any of the cylinders. Pulled the head and the intakes are not closing. I was so close to getting it back up and running, now just a little set back I hope.

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25 Sep 2006 05:20 #79393 by wiredgeorge
Replied by wiredgeorge on topic Valve trouble
Bending the valves by turning the engine over by hand won't hurt anything but the valves... guides are fine. Buy new valves and grind to length. Set the initial clearances using the chart laid out in the KZ1000 shop manual... it will work for a KZ900 head as well... clearances just a tad wide. Anyway, I think I typed this chart out awhile back and put it in the filebase. After installing the cylinder head with the fresh valves, pull the cam chain up in front to remove any kinks/slack and install the exhaust cam and then the intake. Once you have the cam caps torqued THEN check clearances and readjust. They will mostly be fine since you have already shimmed using the assembly chart but you will have to change a couple shims probably.

wiredgeorge Motorcycle Carburetors
Mico TX
www.wgcarbs.com
Too many bikes to list!

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25 Sep 2006 20:05 #79619 by Prune1
Replied by Prune1 on topic Valve trouble
thanks guys...got the valves ordered now that I know my whole head isnt fubar. I will follow those directions exactly making sure to not do the same thing again. noob mistake eh!?

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03 Oct 2006 19:14 #81635 by racer54
Replied by racer54 on topic Valve trouble
Don't feel bad about bending a few valves. My ex-brother-in-law was a certified mechanic and years ago, he replaced all the valves in his head...er..bikes head. He timed it, etc. and started it. You could here a very distinct clicking and he waid it was just loose tappets, which myself and everyone else told him different. Well..to make it short-our master mechanic, who should have known, bent every valve in the head. So it happens to the best of us. It's the hard way, but you tend to remember it better. Keep on wrenching-we all have and that's how you learn to do this stuff.

1980 LTD (changed over the years), 1979 LTD (being rebuilt), 1977 KZ turbo and various KZ's in various states of build. KLX110

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