Valve oil seals & the rope trick - any detailed guide on disassembly order?

[seinwave]

Long story short, my '81 GS650G has started spitting quite a bit of white-blue oil on cold starts out of one exhaust pipe. The amount of smoke is roughly proportional to how long it's been sitting (and the sidestand makes it worse), I haven't noticed any loss in power or roughness, and there's never been any oil smoke after it's warmed up and I'm underway - so I'm leaning towards the valve oil seals being the issue vs rings - but it's starting to burn enough to cause noticeable oil use, so I'd like to replace it soon-ish.

I want to avoid popping the head off if possible, as the price and availability of head gaskets is a little disheartening. It's quite possible I'll need to do a full top-end in the middle future, but I'd rather replace these seals and see if that fixes it first, only popping the head if it doesn't (cost: one head gasket, a "small" number of hours), rather than either diving in now on a top-end (cost: one head gasket, a "large" number of hours") or taking off the head, disassembling the valves the 'right way', finding it doesn't fix anything, then popping the head *again* to do the top-end (cost: two head gaskets, a "large" number of hours).

I've seen the "rope trick" mentioned here - stuffing the combustion chamber with rope or other soft material through the spark plug hole to keep the valve from falling inwards, then disassembling the valves from the "back" (tappet side). This makes sense to me, and following along with the service manual I *think* I can see how to turn its right-way-round operation into wrong-side-out ones. But I'd prefer to have a second frame of reference from someone who's done this before.

Anybody have a written or pictoral guide to this operation?

[Burque73]

Found this for you

https://www.thegsresources.com/_forum/forum/technical-forums/-4-cylinder-engine-drivetrain-clutch/54589-valve-stem-seals-without-removing-the-cylinder-head/page2?t=188696

[seinwave]

Thanks, I searched but didn't find anything nearly as comprehensive as that.

[Burque73]

You're welcome. It took three or four searches with different phrasing.

Good luck!

[sacruickshank]

I've used the stuffed rope technique on an old Goldwing. Worked fine. The key is coming up with a way to depress the springs. On the Goldwing I did this Valve_Compress.jpg

[Steve]

..., only popping the head if it doesn't (cost: one head gasket, a "small" number of hours), rather than either diving in now on a top-end (cost: one head gasket, a "large" number of hours") or taking off the head, disassembling the valves the 'right way', finding it doesn't fix anything, then popping the head *again* to do the top-end (cost: two head gaskets, a "large" number of hours).

Can't help much with the rope idea, but thought I would give you a "heads-up" in case it doesn't work.

You can't just remove the head and replace a head gasket. The process of removing the head will disturb the base gasket, as well, so you will need to remove the cylinders and replace the base gasket, too. OEM gasket has proven to be the best, and is relatively inexpensive.

.

[Burque73]

Whoa, I think I just saw a ghost! Maybe a bot just hijacked the GS whispere's account.

Steve?? Hey, man. Good to see you posting. Hope all is well with you.

[Steve]

No, ghost or bot, it's me.

General health continues to improve after a few "issues" and home renovation is DONE, so there is now time for bikes again.

.

[seinwave]

Can't help much with the rope idea, but thought I would give you a "heads-up" in case it doesn't work.

You can't just remove the head and replace a head gasket. The process of removing the head will disturb the base gasket, as well, so you will need to remove the cylinders and replace the base gasket, too. OEM gasket has proven to be the best, and is relatively inexpensive.

Thanks for the heads up, I hadn't caught that reading through the manual (but it makes sense now that I think it through). The base gaskets and o-rings are much cheaper than the head gasket, but the extra minimum workload for a correct-sided valve disassembly makes the effort and prep for a wrong-sided one look more attractive.

I've used the stuffed rope technique on an old Goldwing. Worked fine. The key is coming up with a way to depress the springs. On the Goldwing I did this

Yeah that's the part I'm having to think through now. On the GS the cam-holder bolt holes are not in the same plane as the valve assembly is. I'd be loathe to put strange off-axis forces on them in perfect circumstances, and I'm already a little suspicious of the general state of the cylinder head - a few bolt holes for the valve cover have had their threads turn to chalk. I have workarounds for the cover bolt holes but the camholder bolt holes going bad would be catastrophic. Also don't have a crash or highway bar like the above example for an easy external place to leverage from. Hmmmmm.

[Big Block]

Yup: I did them on my 16V 1100 and building fixtures to press down the spring and retainer was a real bear. I was welding and cutting bits to make it work and still needed a third hand to press them down and magnet out the keepers, I'm just glad the engine was out of the bike. Feeding in the rope is definetly the easy part of that chore.

[Buffalo Bill]

For my 1100G, I decided it was better to take the head off and do much more: de carbon chambers & piston tops, replace a few worn valves & lap them all in, some mild porting, and shim replacements.