'79 XS project by a mechanical newbie. (But hey, it was free)

[stoneairsoft]

Got my compression tool in the mail today!

Popped the #4 exhaust and intake valves off. This is the grime I found. Going to try and lightly sand it away.






My gasket set included these small rubber o-rings, but I didn't see any as I took the old stem seals off. Are they for something else? The old stem seals actually looked pretty good until I broke them a bit extracting.

[stoneairsoft]

Please see above post as well:



I know I'm desperate to save $50 here, but is this head gasket viable?
The gasket had those clips that sit inside the chain well, but those came off the gasket when I removed. According the Yamaha manual, "Install cylinder head gasket. Locate the cam chain cavity cylinder seal with the tabs down..." or is the seal SUPPOSED to be separate?
I also lost a couple of bits on the corners here. I'm wondering if I can use Yamabond or the like to reseal.

[skids]

The newer head gaskets have the cavity seal incorporated into it. Does this answer your question about that? I don't know if Yamabond will be adequate for that (sorry). The valve "looks" oil fouled. Is it rock-hard? If so, it might be tank liner or something else (don't know).

[stoneairsoft]

Thanks Skids, Guess I'll have to bite the bullet on a head gasket. Of all gaskets! Grr. With regards to the chain gap/sealer, on page 158 of the PDF (or 3-45 looking at the scanned number) http://ringler.us/xs1100/XS1100H-SH-...ice_Manual.pdf it looks like a separate piece they lay in.

Basically every valve looked similarly crappy. I took a drill-mounted non-metal brush grinder to get them at least presentable smoothness rather than that black crap.


Any idea what the o-rings in my pic might be for? I'm holding off putting the new valve seals in until I can double check they don't go in somewhere.

The newer head gaskets have the cavity seal incorporated into it. Does this answer your question about that? I don't know if Yamabond will be adequate for that (sorry). The valve "looks" oil fouled. Is it rock-hard? If so, it might be tank liner or something else (don't know).

[DiverRay]

How many O rings are there? They do NOT go on the valves, that I do know. They may be for the later engine with the YICS system, but I'm not sure as I've not worked on one.

[Ranger_xs1100]

head gasket

If you are using an aftermarket head gasket, don't use the original little gasket insert that is around the cam chain well area. Just leave it out, as skids stated, it is integrated into the new head gasket. hope this picture helps clarify that:

[3Phase]

Get a new head gasket.

The o-rings are for the valve guides. You won't need the o-rings unless there are leaks in the head around the valve guides (not a good sign) or you're taking the head to a machine shop to have worn out and hammered valve guides replaced.

Easy-Off oven cleaner works to get rid of the carbon on the intake valves, combustion chambers, and the some of the crud in the exhaust passages.

I haven't found anything that'll touch the baked-on stuff on the exhaust valves, those have to be scraped/wire-brushed and cleaned by hand.

[stoneairsoft]

UPDATE:
All valve stem seals are replaced, cleaned up valves put back in(I have break parts cleaner spray I considered using, but wasn't sure how sensitive the valves were to such chemicals...I didn't know about the oven cleaner), head gasket scraped off (thanks for the info about that funky chain bucket piece) and exhaust cam put on while the head is still out...using my in/lb torque wrench.

I have a question about valve clearances. And before you mention it, yes, I read all kinds of posts on the site about it, including the "pictorial" in the maintenance section. I want to know if there are particular positions the lobes should be in when measuring. I have a 1979 Special. Are the exhaust clearances indeed 0.16~0.20mm and the intake 0.11~0.15mm? I could read all but one of the thicknesses stamped on the back of the shims. Most were 290 or 285, which seems to be on the bigger end, and the bike (I believe) only has like 16k on it, so that would make sense?


I twisted the feeler gauge a bit so you could see the number. Both read the same with a little resistance but with the lobes in different positions. Exhaust #2 lobe is at about a 90deg angle and #4 is at about 180deg. All the exhaust clearances "appear" dead on.



al2 co3

[Ranger_xs1100]

The pointy end of the cam lobe should be pointing up...180 degrees from the valve shim...I don't think you'll get an accurate measurement at 90 degrees.

[stoneairsoft]

Ah, thanks...so at a right angle relative to the shim.

Also, shouldn't I expect the clearances to have gotten TOO big from use? If anything, they're too narrow. One of the intakes even being .8, smaller than spec.

[DiverRay]

Also, shouldn't I expect the clearances to have gotten TOO big from use? If anything, they're too narrow. One of the intakes even being .8, smaller than spec.

That is correct. The valves TIGHTEN UP as they wear! Set all the valves to the LARGEST value, .15mm Intake and .20mm Exhaust. And, just to be SURE I would check them one more time before putting the valve cover on once the head has been installed and cam chain back in place.

[motoman]

Ah, thanks...so at a right angle relative to the shim.

Also, shouldn't I expect the clearances to have gotten TOO big from use? If anything, they're too narrow. One of the intakes even being .8, smaller than spec.

Answer to first statement...…….relative to shim, highest point of cam lobe NEEDS to be at top of travel, in other words, 180degrees relative to shim/ bucket assembly. Right angle as you stated is only 90degrees.

[skids]

UPDATE:

I have a question about valve clearances. And before you mention it, yes, I read all kinds of posts on the site about it, including the "pictorial" in the maintenance section. I want to know if there are particular positions the lobes should be in when measuring. I have a 1979 Special. Are the exhaust clearances indeed 0.16~0.20mm and the intake 0.11~0.15mm? I could read all but one of the thicknesses stamped on the back of the shims. Most were 290 or 285, which seems to be on the bigger end, and the bike (I believe) only has like 16k on it, so that would make sense?

Intake (0.16 to .020) & Exhaust (0.21 to 0.24) for 78 and 79's.

[skids]

Intake (0.16 to .020) & Exhaust (0.21 to 0.24) for 78 and 79's.

PS, cam lobes straight 90 degree out from the surface of the shim for the measurement.

[stoneairsoft]

Thanks for all the clarifications. There's so much info & so many variations...I was looking at the XJ manual for the clearances.
I should have clarified the lobe placement, but we're all on the same page...pointing away from the shim.
I'll recheck clearances tomorrow. Bummer. They must all actually be off if I was using the XJ specs