Head issues... Yeah, mine...

[KA1J]

Today I removed the head on the XJ11 to look for causes of very low compression Read here: http://www.xs11.com/forum/showthread.php?t=32359 & I had a bugger of a time getting it off. I had to resort to pounding upward on the head with several different pieces of wood & a mallet. Problem was on the left side of the head, it seemed like it was being held by a bolt but all the nuts were freed.

The problem getting the head off was it turns out the stud between exhaust 1&2 was rusted and somehow the shaft was filled with rust. Doesn't make sense on an aluminum head engine but this stud and the one between exhaust Cyl 3&4 were all rusted. The one between 3&4 came out of the block instead of the nut unscrewing. Below you see how the shaft in the cylinder is filled with rust where the head came off, the stud does not move... It was all I could do to pound the head upwards to force it off. You can see the rust embedded into the threads from the pressuers generated when I pounded the head up & the rust in the channel got jammed into the threads.



Here is a shot of #2 cylinder where the low compression was found:



Here's Piston 1 which cylinder had pretty good compression



Bottom of the head showing the valves:



Here are the valves for cylinder 2 which had poor compression as did 3:



And here's Valves for 4 which had good compression:



I'm going to try and remove the cylinders tomorrow & to prepare, I squirted quite a bit of kroil along the rust surrounding & holding the stud in place in hopes it'll not give me too much resistance.

Any idea why those two studs rusted like they did & more, there does not seem to be enough rust on the shaft of the studs to account for the volume of rust that was in the shaft. Literally there were chunks or compressed rust I found 1/2" long & semicircular where they fell off when the head came off. All from that stud.

Amazing...

Thoughts on the above & anything looking off with the cylinder & valves?

Thanks!

[DiverRay]

When the bike has been ridden in the rain, the two front studs WILL RUST. Remember, rust is a cancer, and will spread unless checked.
To pull the barrels, use a 2" putty knife and slowly tap it between the barrel and the case. Use it to cut the gasket, and create a little bit of room. EXPECT THIS TO BE HARD, AND GO SLOW! I broke some fins on the first one I tried, but the second time was easier.
I think you can find "new" studs that will fit. I have not looked yet, because I'm not to that point on the engine. Try looking at some of the speed catalogs for cars, and see what length studs they use. These ARE 10mm, so they should not be that hard to find.

[crazy steve]

If you look carefully, you'll see that all the head/cylinder studs are exposed to the weather. Like Ray said, riding in the rain or my favorite, failing to thoroughly warm the bike after washing can both cause water to get to the studs and start rust. And rust never sleeps...

And your cylinders don't look all that bad. I don't see a ridge, you may have just stuck rings. While you have the head off, it would an excellent time to check the valves and at least give them a light lapping...

[melbxs]

I notice that there's a lot of carbon leaching out from the cylinders that you said had bad compression.

The number 4 has one tiny spot outside of the cylinder, but hardly any.

Is it possible that the head hasn't been torqed down properly and you were losing a bit between the head and the gasket?

Another possiblity is that the head has warped, so check that out.

Pour a measured bit of gas into each cylinder and time how long it takes to drain past the rings on the good cyls and the bad ones. This will tell you of the rings are shot.

Don;t run the bike after diluting your oil with gas though.

[motoman]

Makes perfect sense. On top of what Ray said, look at your location. Can pull a head off of one of these HERE, and wa-la......no rust anywhere. Studs will have just a white kinda powder on them. See stuff like this and appreciate even more of my location!......just saying..

[natemoen]

Dont know about the xj's but on at least the early xs's there was a sleeve or something that was put around the head bolts to stop any possible rattling and rust, well they became quite counter productive because they just disintegrated and became worse than rust.....yeah it sucked pulling my jugs off!

My next question is why did you decide to tear the thing down when everyone suggested to ride it more before making that decision. I will say that I completely regret not putting more miles on my engine before tearing the jugs off. Granted I was burning through about a quart of oil per 50 miles but I still regret doing it and not giving it more time to possibly correct itself on its own. Even at this point in your tear down I would absolutely say STOP. Get a new head gasket (it does kind of look like there is some bleed through between cylinders) and put the head back on and drive the thing when the weather is nice out.

Like I said, I totally regret jumping in and pulling my jugs off and wish I had waited and I dont want to see that happen for you too.

[Rickrider]

Not an expert on these particular engines but rusted cyl bolt, brown on the exhaust side of the head gasket looks to me like leaking head gastket, exhaust side. Some one else suggested a test for the rings, I would seriously consider this before tearing down further, 'cause it looks to me like a gasket problem (or warped head?)

My $.02.

[natemoen]

Not an expert on these particular engines but rusted cyl bolt, brown on the exhaust side of the head gasket looks to me like leaking head gastket, exhaust side. Some one else suggested a test for the rings, I would seriously consider this before tearing down further, 'cause it looks to me like a gasket problem (or warped head?)

My $.02.

Never thought of warped head, but I do agree that It is most likely NOT rings or something else lower down.