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1982 gl500
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Discussion Starter · #1 ·
Curious how many stories like this everyone else has...
I got my GL500i cheap because someone smeared a ton of RTV on the head gasket and the bike wouldn't run right. They didn't just glue it on, they smeared the crap out of it. You can see it in the pictures, there was a bunch in the combustion chamber. Seems like they covered the whole head in a thick layer of RTV before putting the gasket on, including the flat area around the valves. They glued both sides too. I am honestly amazed it ran without overheating due to the restrictions in the oil and coolant galleys.
The story I heard from the previous owner was that the original owner had it for 10k miles, then it overheated in the mountains, blew the OE gasket. The original owner fixed it then sold it to the guy I bought it from, who parked it in his garage and started stripping it down to cafe it, but that project stalled out a decade ago because it wouldn't run right, and it had sat since.
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Reminds me of this video:

 

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1982 gl500
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Discussion Starter · #5 ·
I would drop the engine, remove front and rear cases, and both heads, and get it all out, and check everything involved in a potential quadruple bypass while you are at it.
I am a couple steps ahead of ya there. I will be replacing everything in the engine that is made out of rubber too. Got it almost torn down to the block, pulling the crank out this weekend. It was making a crunchy noise, like a bad chain, so I wanted to get the back case off anyways. But it turned out to be the cam, chain looks fine. Figured while I am in here I will do the full A+B gasket kit, upgrade the stator to a G6, and will be porting the heads, and getting the valves and seats ground. Even though the chain looks good I already bought everything for a new one + guides, so I will just swap it all in. I will hold onto the 10kmile used parts as spares for my other bikes.
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Porting pays good dividends on these. I've done two of mine now.

While both were ported with Murrays mikunis in mind only one currently runs them. The other is currently fitted to a bike with full stock intake, though with a K+N filter.

Both go better than stock. The one running keihins also has 180 PSI cranking compression, lightened, polished and balanced crank and reciprocal assemblies, 600 grams off the rotor and a raesan ignition.

The other has ported heads, mikunis, raesan ignition and a modified cam sprocket that gives slightly retarded cam timing in a bike 29 kg. lighter than stock.

You can get these to perform better.
 

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'84 CX650E that is evolving into a GL500
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It looks like another case of someone with a poor grasp of how things work hearing that a small bead (or thin layer) of silicone can help gaskets seal better and make them easier to remove the next time and deciding that if some is good a lot must be better (not to mention that they didn't grasp that the silicone must be allowed to cure before assembly and that the heads will reach temperatures in excess of what the silicone can handle).
 

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Don't forget to also flush out all the water passages, including the radiator, heads, and water pump, who knows how much of that crap got into there.
 

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1982 gl500
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Discussion Starter · #9 ·
Porting pays good dividends on these. I've done two of mine now.

While both were ported with Murrays mikunis in mind only one currently runs them. The other is currently fitted to a bike with full stock intake, though with a K+N filter.

Both go better than stock. The one running keihins also has 180 PSI cranking compression, lightened, polished and balanced crank and reciprocal assemblies, 600 grams off the rotor and a raesan ignition.

The other has ported heads, mikunis, raesan ignition and a modified cam sprocket that gives slightly retarded cam timing in a bike 29 kg. lighter than stock.

You can get these to perform better.
I've got Murray's carbs, an ignitech, some nice coils, and a free flowing true dual exhaust that I just repacked with fresh glass. I am going to remove the fan and go with an electric as well. And while I have the crank out I will be polishing everything, maybe shim the valve springs a bit. The bike is also a bit lighter since I removed the cowl.

What did you do to lighten the cam sprocket and the crankshaft? I would consider drilling some holes in the sprocket but I don't have access to any sort of balancer.
 
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