How can you tell what year your KX500 cylinder is?

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How can you tell what year your KX500 cylinder is?
89-04 is easy.
If you have a 3 valve set up it's 89-04 and they are all the same.

89-04 KX500 CYLINDER.jpg (162.47 KiB) Viewed 7967 times

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Here's where it gets a bit more tricky.
86-88 kx500's all have two valves,

86-88 cylinder.jpg (167.69 KiB) Viewed 7967 times

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So, how can we ID the 86-88 cylinders?
The 88 is the only year of the 3 that uses 8mm standard head studs like this:

88 kx500 cylinder head studs.jpg (88.4 KiB) Viewed 7967 times

Both 86 and 87 use counter bored studs like this:

86-87 kx500 head studs.jpg (98.94 KiB) Viewed 7967 times

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So how can you tell the 86 from the 87 cylinder?
Apart from the exhaust degree timing there is a easy visual way.
Take a look at this 87, note the compression reliefs on the kips valve ports:

87 kx500 cylinder kips compression reliefs.jpg (67.93 KiB) Viewed 7967 times

Now take a look at the 86 kx500 kips ports, note that there is no KIPS compression reliefs:

86 KX500 KIPS PORTS WITH NO RELIEFS.jpg (146.78 KiB) Viewed 7967 times

So that should help you out.
There may be other visual ID difference as well, but these are the ones I know about.