So recently my GS500 started leaking pretty badly, a drop every 10 seconds or so but only while running. It was coming somewhere from the right side of the engine, covering the frame rail and dripping from there. I figured it was the clutch cover gasket which I had replaced about a decade ago for a similar reason. I replaced that but the issue persists. It's not coming from behind the signal generator. It looks like it might be coming from the front right corner of the engine, where the two case halves meet. But my maintenance manual says there's no gasket between the cases - so is that possible? And if so, what to do about this - do I have to split the cases? >:(
Clean the bike really well with degreaser, brake cleaner, etc.
Then dust some talcum powder over the engine where you think the bike might be , go for a very short ride and the oil will leave a clear line in the powder.
Nothing visible? ride a little further.
Once you are sure where its coming from it should be easy to identify the fix.
Good luck!
Agreed, do the powder trick to find the actual leak source. The bikes and parts lean/have slope so oil can drip from somewhere it didn't leak from. My money is on cam chain tensioner gasket. That's a common one that runs from the back along the cooling fins and drips up front. It's relatively easy to replace, especially if you take the carbs off.
Or could be valve cover gasket (common and Easy to replace) or cylinder head gasket (hard to replace) or base gasket (hard to replace).
Thanks all! Next time it's warm enough here I'll do the talc trick.
I took a closer look. The cam chain tensioner is fine. The base and head gaskets seems OK, I wiped all around the base and it didn't get oily. The valve cover gasket has a spot where I clearly didn't reinstall it right, it looks like it got pinched into the valve area (my fault). There's some oil around there but it doesn't seem to be running down too much - but I'll need to fix this anyway.
In this diagram it looks like part 27 is a spacer that lets the crankcase mount to the frame - is that right? Does the bolt (23) go through the crankcase, such that if the seal around 27 was broken, oil could leak out?
Some maybe good news. I cleaned off the engine and started the bike again and ran it for a few minutes to look for the source of the leak. And...nothing happened. So it looks like it might have been the clutch cover gasket after all, and the drips last time was oil already on the engine heating up and dripping off. At least I'm going to hope this is the case.
I will need to replace the valve cover gasket but that doesn't seem to be leaking much.