Valve Guide Leaking.

Hi All,
I have had my long term project 750 commando running today and it starts & idles OK but when it warms up it smokes excessively on the left hand pot.
I did a compression test & both side are over 150 PSI so I removed the left exhaust pipe and you could see a pool of oil which appeared to have drained down from the top ( between valve or exhaust guide).
I have had this happen historically on another two 750 engines of mine & both times left side exhaust guide.
I cured these with oversive guides but my question is has anyone else suffered this & would it be an idea to use some form of Loctite on the guide?

Thanks in advance.

In my experience, exhaust guides don't contribute much to oil consumption. When an exhaust valve opens, the pressure is in the wrong direction to be sucking oil into the combustion chamber. Intake guides however will let oil get pulled into the motor during high vacuum conditions like idle and blipping the throttle. That's why they have rubber seals and the exhaust guides don't.

Oil can pool to the left side of the rocker box when the bike is parked on its side stand, and you may see some in the left exhaust port if the guide is leaking. But the smoke it causes will be after startup, and it'll clear up as the engine runs.

You need to figure out if it's a valve stem clearance issue or if the guide-to-head interface is leaking. The former requires new guides. The latter may be helped with Loctite green sealer, designed for bearing retention. It's only good to about 400 degrees though, and I've used it successfully with intake guides but never tried it on the exhaust side.

Again, smoking after warmup (IMO) is not likely due to exhaust guides.

Had this problem years ago with a 650ss, a drop of STAG B smeared on the guide did the trick..and its heat ,oil resistant and none setting,

If its blue smoke its burning oil form the inlet side. If its white, its vapourised oil from the exhaust side. The usual problem is a loose guide or scoring in the guide bore allowing oil into the exhaust port.

Mick

Hi All,
Thanks for the replies.
The bike is now fixed with no leak or smoking from the head or exhaust.
All the original guides were new so I fitted an oversize guide to the left exhaust with loctite and all is good.