turns over but intake valves stuck open

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22 Jul 2022 16:39 #870865 by 82KZ305Belt
turns over but intake valves stuck open was created by 82KZ305Belt
I need new cylinders and found a very low miles engine in this condition.  No compresion obviously, so obviously I don't know what condition the bores are in, so is this a complete waste of time to consider? I'm not sure what the stuck valves might mean for the condition of the cylinders, or if anything can be reliably assumed from it. I'm not even sure how it can turn over with stuck valves

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22 Jul 2022 17:00 - 22 Jul 2022 17:03 #870867 by TexasKZ
Replied by TexasKZ on topic turns over but intake valves stuck open
If a valve is actually stuck, the crankshaft could not make a full revolution unless the head of the valve is broken off and bouncing around in the cylinder. I would pass unless I could get a bore scope in the cylinders to confirm their health.

I suppose it could be a sticky valve that is being pushed almost closed by the piston. I would still wqnt to look inside first.

1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
Last edit: 22 Jul 2022 17:03 by TexasKZ.

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22 Jul 2022 17:50 #870869 by Nessism

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22 Jul 2022 18:07 #870871 by 82KZ305Belt
Replied by 82KZ305Belt on topic turns over but intake valves stuck open

Bent valves most likely.  Time to pull the head.


 
How do valves get bent on a low miles (<5000) bike? Neglect? Abuse? Don't really care about the valves but if it could indicate piston/bore problems, I care a lot

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23 Jul 2022 00:06 #870884 by howardhb
Replied by howardhb on topic turns over but intake valves stuck open
Abuse most likely, whether intentional or mistaken... down-shifting, instead of up-shifting gears at max RPM, 
 causing over-revving, whereby the resulting velocity / inertia of the valves is greater than the valve spring's ability to maintain the valves following the profile of the cam lobes, and out of eachothers way, and, out of the way of the pistons!

H.

'81 GPz 550 D1
'81 GPz 1100 B1 ELR "Tribute" www.kzrider.com/our-forum/11-projects/61...-elr-tribute?start=0
'82 Yamaha YB100 Fizzie
'79 Suzuki GT200 X5 TWO STROKE TWIN - SMOKER!

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23 Jul 2022 07:35 #870896 by 82KZ305Belt
Replied by 82KZ305Belt on topic turns over but intake valves stuck open
Owner now says the intake valves do not move, so if it is truly turning over that must mean they are broken off.  Sounds like cylinder damage is likely too. Scratch another one from the dwindling list...

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