Oil leak

[Christopher]

Hello Everyone. My gs850 is leaking oil from somewhere on the front of engine. I noticed some smoke which i think might be oil dripping on the headers. Could it be the speedo cable to cam cover? Any advice is appreciated?

[Christopher]

[Rich82GS750TZ]

Not your speedo cable, actually your tachometer cable. Yes, that is a common and likely place to spring a leak. Follow link to rebuild tutorial. There are some model differences but the oil seal and oring are typical for most GS models. As always, check a parts fiche from a reputable online OEM parts dealer (lately, I like partshark.com) before buying from them or your local dealer or other sources. Assuming Tamworth Staffordshire is in the UK?, try https://www.cmsnl.com/
This tutorial found on BikeCliffs website, linked in my signature. https://www.bwringer.com/gs/tachcableseals.html

[Grimly]

Sometimes, the inner shaft of the tacho drive is too knackered to be kind to a replacement seal, so a new tacho drive is the only option.
MandP have stocks of them from time to time.
Looks like they're back in stock for now...

https://www.mandp.co.uk/products/suzuki-gs-gsx-late-70s-early-80s-tacho-drive-unit-467999-678288

The costs of the two tiny seals and postage near enough amount to the same as the new drive unit.

[Rich82GS750TZ]

Also looks like your valve cover gasket it hard and crusty, probable leaking too. If you haven't had the cover off to do a valve adjustment or know when it was done and by whom, you're going to want to do that sooner than later.

But fist things first: Best way I've found to find the source of the leak is to thoroughly clean and dry the engine. Spray foot powder in all areas of possible leaks. Then run the engine. Leaks show up in the powder pretty quickly. Be sure to wash the powder off before it can get baked on.

[Christopher]

I just bought this bike and the guy assured me it didnt have any oil leaks. Hope its not too serious im a bit worried its the head gasket. Ill clean it up and get a better idea. Thanks for the advice

[Rich82GS750TZ]

I’m under the impression that many bikes go for many miles with minor oil leaks from various gaskets. Just sayin’, depending on what you want from this bike, maybe some things can be tolerated, for a while anyway, for the sake of enjoying the ride rather than wrenching.

[gtem]

You've got probably "all of the above" in terms of leaks, like I did with my 1100E when I got it. Tach seal, valve cover gasket, likely a cam chain tensioner (believe it or not that oil can travel towards the front of the engine, in my experience), and yes, a head gasket and/or base gasket. The good news is that none of this is dangerous/critical to engine operation as long as you don't run it too low. You can run an aircooled bike with an externally leaking headgasket, almost indefinitely if you don't mind a minor mess. Tach seal is an easy one to knock out, valve cover gasket, good one to do while adjusting valves, just avoid the cheap "ebay" pattern ones, they tend to not be thick enough and not seal well. You could de-grease and wash the engine and see where the leaks re-emerge as well, to get a better idea of who the worst offenders are on your particular bike in terms of leakage.