valve stem seals, methods to access and replace?

Joined
Dec 4, 2012
Messages
1,263
Age
61
Location
Vienna, AuSTria
Bike
ST1100Y, ST1100R
reaching the 100k miles on the '00 ST, and the (frequent) urban use demands his tribute to the heat of slow moving in dense traffic...

Already last summer/fall I noticed an oh so slight 'oily whiff' upon starting in the sub-level garage, vanished once on the move though...
To me its getting a little more prominent now, like catching up with you when stopping at a red light... 🤔
Nah, still absolutely no smoke upon whacking it, no "sooth" in the end-pipes, but even ze GF started to pick up the scent, mentioning "I think you're a little smelly!" on the bike2bike... ;)

So while I had the carbs out (swapped them with an overhauled set to eliminate this as cause of bad odor) I peeked down the inlets and indeed:
the valve shafts appear shiny, "moist" if you will, no drops, nothing accumulating there on top of the valve heads... yet... but... rubber hardens over the years, heat-cycles, decades, K miles...
(since the '94 with higher miles still doesn't show such, declining material quality/change of vendors on late models might also play along...)

So I did an oil-change and an extended shakedown run on the weekend, which showed significant improvement (read: ze GF cannot detect anything anymore 😏) but I know its there, so how to attack that issue? 🤔

a) the "classic" way; heads off (= requires new head gaskets), clamp-on valve-spring compressor to lower the retainers to get the collets out, etc... ?

b) the crude way; stuff some rope down the plug hole, rotate cylinder to TDC to jam that against the valves, attach a rail to the head, and use a retainer compressing lever there ?

c) try the modern way with a plug-hole air-hose adapter to hold the valves up by air-pressure (AFAIK are motorcycle valve springs heavier then car types to cope with the RPMs... will 10Bar/140psi even be sufficient) ?

yeah, it'll take some efforts, but since such won't "heal" the miraculous way, it needs to be addressed IMO...


Anyone gone that road willing to share tips on tools and insight? 🤔
TIA
 
Last edited:
OK, did some research...

this kit seems rigid, well made and somewhat adaptable for the job:


and not to forget: the protector for the (precise) bucket bore; you don't want to scratch that up... 🧐


I would like to avoid having to pull the heads...
Performing this 'surgery' minor invasive from the top would require only new valve cover gaskets and grommets... and be done in like 1/4th of the time... 🤔
 
Last edited:
I might make this decision based on ...which method means I get to buy the most tools 🔧?
Au contraire...
Darn head gaskets come between € 60~95,- a pop (depending on vendor)...
The we've to add the paper ones where t/belt casing meets the heads...
Plus the work, efforts and risks(!) when actually removing the heads...
Methinks I'll bite the bullet and go for the € 100,- kit plus that plastic protector/cup...
 
c) try the modern way with a plug-hole air-hose adapter to hold the valves up by air-pressure (AFAIK are motorcycle valve springs heavier then car types to cope with the RPMs... will 10Bar/140psi even be sufficient) ?




Anyone gone that road willing to share tips on tools and insight? 🤔
TIA
You don't need a lot of air pressure to hold the valves up. Get whatever cylinder your doing to top dead center. Just incase something should happen the valve can't fall out. Then you need to lock the crankshaft down to prevent the piston from going down from the air pressure. Bucket type valve springs don't give you a clear shot at the keepers.

1783974713361.png
 
c) try the modern way with a plug-hole air-hose adapter to hold the valves up by air-pressure (AFAIK are motorcycle valve springs heavier then car types to cope with the RPMs... will 10Bar/140psi even be sufficient) ?
The strength of the valve spring has no bearing on how much air pressure is required in the cylinder to keep the valve closed. The valve spring isn't pushing the valve open against the air pressure, it is attempting to close the valve.
 
Back
Top Bottom