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1985 cmx250
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Discussion Starter #1
Well just done a compression test and found out that the left cylinder wasn't getting any compression at all. Bike only has 22 original miles but has been sitting since 89. Not sure what next step will be. Any help would be appreciated.
 

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Is there a way to get it unstuck or some way to check it.
I would start with heating the engine with a heat lamp, remove the valve cover and squirt some penetrating oil down the shaft of the offending valve stem and let sit for a couple of days. You may have to repeat a couple of times. If that doesn't release it try a propane torch on the casting around the stuck valve.
 

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You could remove the valve cover, put the bike in gear, and with the rear wheel raised, try to turn the rear wheel by hand. That might allow you to identify which valve is stuck without bending the valve shaft, if it isn't already bent. If that doesn't work, treat all of them as DNMenzies outlines. And if it's still stuck, you're going to have to pull the valves.
 

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You could remove the valve cover, put the bike in gear, and with the rear wheel raised, try to turn the rear wheel by hand. That might allow you to identify which valve is stuck without bending the valve shaft, if it isn't already bent. If that doesn't work, treat all of them as DNMenzies outlines. And if it's still stuck, you're going to have to pull the valves.
I an assuming the valve is stuck open and not bent. When ever I shut my lawn mower down for the winter I always stop it on compression so both valves have to be pushed to move them on a restart, if one valve sits open it will frequently stay there. I have a Model T and I run it not too frequently but on two occasions I had a stuck open valve that required a slight tap with a hardwood stick to release it. You may be able to design a probe through the spark plug hole to force the offending valve closed.
 

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1985 cmx250
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Discussion Starter #7
Thank you everyone for all the help. Gonna grab some on blaster later and soak the valves hopefully with valve cover off I'll be see which one is stuck and also hoping it's not bent. I'll update when I find out further information
 
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