Mailman’s XS2 , pulled the engine for top end repair

Okay, made it home from quite a Christmas trip. (Very wintry)
I just hate to chime in, in what could be taken the wrong way. But.. over the years as an XS650.com member I have repeatedly and continuously emphasized parts sourcing as much as possible locally (within hundreds of miles) and in person ! I currently own two XS650 fuel tanks. Pics..
A guy CAN find good parts still. It takes determination, but if you are just shopping online you do not have a chance to score the good stuff!
Get the f@k out there everybody! This is a dying hobby and it takes leg work, phone calls, and gasoline!
BTW, I am fortunate in that ethanol free gasoline is within bicycling distance.
 

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Ok, I pulled the head off today and here are the inside engine shots. Crosshatching still visible in the bore, pistons look black and oily, but that’s not oil, it’s sticky. Slow going cleaning all the build up from inside the intake tract, worked all afternoon with an Xacto knife. The debri in the photo is just from the left intake tract and left valve. I’m thinking now that I should pull the barrels off and check the pistons and make sure none of the rings are stuck.
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Well I was hoping for the best, but I think you're right. The top land and groove are most likely gummed up.

Im thinking that I could clean the rings up without removing them from the pistons , don’t you think? I’d hate to break one.
 
Im thinking that I could clean the rings up without removing them from the pistons , don’t you think? I’d hate to break one.
Maybe. Hard to say unless you look at 'em. You might actually find there's nothing there 'cept a bit on the top land... and wish you hadn't pulled the jugs. Or...

I'd guess it's stopped at the top ring, so worst case you might have to pull that one, I doubt it went further than that. You have a pair of ring expander pliers iirc?
 
Maybe. Hard to say unless you look at 'em. You might actually find there's nothing there 'cept a bit on the top land... and wish you hadn't pulled the jugs. Or...

I'd guess it's stopped at the top ring, so worst case you might have to pull that one, I doubt it went further than that. You have a pair of ring expander pliers iirc?

Yes I have ring pliers.

Does it melt away in solvent. Otherwise, I think you have to remove the rings.

I thought maybe some acetone would do it? The stuff I scraped out felt kinda soft, almost like dried tar.
 
No point in not pulling the barrels now Bob - that's a whole heap of sh*t you removed from the valves and intakes and you can't be sure that's there's not ring troubles unless you look. As for solvent, start with fuel - that's what melted the stuff in the first place, then acetone and work your way up to whatever MEK is (?), 'cause it sounds dangerous though, undoubtedly, effective. Maybe one of the softer stainless steel wheels on your drill will move the softened crap but not the metal. New gaskets and Threebond and you'll have it back together before dinner time.
 
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Yes, I'd pull the jugs off too. I'd also put some oiled strips of rags through the valve guides to protect them during your clean-up process. Paint stripper may work well for final cleaning on the ports. You can use it to remove the small amount of carbon buildup on the piston tops and in the combustion chambers too. Once you've scraped most of the gunk off the valves, you can finish cleaning them with a wire wheel. I think I'd give all the valves a quick hand lapping with fine compound to clean the seats up too. Shouldn't be a need to go the "full monty" on them (coarse then fine compound).
 
Yes, I'd pull the jugs off too. I'd also put some oiled strips of rags through the valve guides to protect them during your clean-up process. Paint stripper may work well for final cleaning on the ports. You can use it to remove the small amount of carbon buildup on the piston tops and in the combustion chambers too. Once you've scraped most of the gunk off the valves, you can finish cleaning them with a wire wheel. I think I'd give all the valves a quick hand lapping with fine compound to clean the seats up too. Shouldn't be a need to go the "full monty" on them (coarse then fine compound).

Good ideas all around. I think that’ll be my plan!
 
Progress Report,
Ive spent a couple of days scraping and cleaning, the head and valves. Removing the head gasket, scraping crud off the valves, painstakingly removing baked on gunk from my intake tracts. After getting everything off, I shined up the valves and combustion chamber with wire wheels and a Dremel. Once everything was clean, and shiny, I used my Dremel to remove some of the very rough castings inside the intake tract, then I lapped the valves in.
Before,
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After,
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Before,
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After,
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the valves lapped in nicely,
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I still need to give this head a good wash and blow out to get rid of any grit and residue, then I can reassemble it.
I’m pretty happy with the results, it was tedious going for sure.
Later,
Bob
 
Jeebus, Bob! I haven't checked in on this thread in a while. I knew you had failed liner but I didn't realize it'd gotten sucked into the engine. What a friggin' mess! I'd have veins popping out all over the place I'd be so pissed.

Looks like you've overcome the worst of it tho. Have you pulled the jugs and checked the rings yet?
 
Have you pulled the jugs and checked the rings yet

I will be doing that soon, I’m pretty sure at least the top rings will be stuck. I even had to clean out the valve guides, they felt gummy , I had a skinny spiral wound brass brush ( like a rifle bore cleaner ) that I ran through there with solvent. Freed them up nicely.
Also will be disassembling the clutch to clean up all the plates, the clutch was sticking something fierce.
 
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