Valve Stem Seal Replacement

[IanDMacDonald]

I'm going to nab a cylinder head off one of my spares. I'll ensure it's clean, but I'm debating on pulling the valves and replacing the valve stem seals. Any thoughts on whether this is necessary?

I'm also contemplating going one step further and pulling the cylinders and checking tbe rings, and possibly rehoning the cylinders.

Thoughts?

[IanDMacDonald]

Rah. Quite the rabbit hole! I'm comtemplating pulling the jugs, but the labor involved in honing & reinstalling the pistons may not be worth it, especially if everything looks okay . . .

[Radioguylogs]

I feel valve seals are definitely worth doing while the head is off. You know I just had to replace the valve seals on my SF, so maybe I'm not the guy to ask.

Regarding the piston rings,.... If this is the big bore engine, I'd be inclined to keep it "as is" due to the unique rings.

If it's not the big bore engine, I'd make a decision based on the amount of miles on the engine. If it was less than 30k or so, I'd be inclined to keep the original rings. If it was over 40k miles, I'd consider a re-ring. Just my feeling, not based on any unique knowledge. I can say I did a re-ring on and XS750 @ 20k miles because the base gasket was leaking, so the jugs had to come off. Those cylinders were 0.001 out of round at the top and bottom, perpendicular to the wrist pin.

[bikerphil]

100% do the valve seals, not the guides, they last forever.

[IanDMacDonald]

Thanks, gents! It is the big bore engine. I think I'll leave the cylinders alone.