Oil leak from points cover.CB550.

[andy120t]

Is it possible to have a leak from the points cover?. I have an engine in the bike that I haven't run, beyond briefly firing it up - bike had the oil topped up and was happy sitting on the side stand but when I propped it up more vertically ( wood under the side-stand) I found a puddle of oil.

Are their seals that could leak, and if so, are they easy to replace without major surgery?!

[taysidedragon]

The only oil seal behind the points is the crankshaft seal, if that's leaking it's an engine split to replace.

[SteveW]

You could try Wynns Stop Leak, it’s supposed to revitalise seals. Worth a try for about a tenner.

It slowed my output shaft leak on my 650.

[Oddjob]

Remove the points plate and you can see the crank seal, as TSD has said it's normally a split the cases job to replace, that's because it's lipped on it's outer edge. First off you need to make sure it's that that is leaking, it could be the crankcase sealing itself. You could possibly get away with removing the seal, if it is that, and removing the lip off a new seal and driving it into place, it may work and for the cost of a new seal it may be worth trying first. However that's not without it's risks, the seal is very close to the crank shells and if you hit those you're in a lot of trouble. It has been done though.

[andy120t]

Thanks all - that's a start and some useful pointers! I've been mulling it over and looking at parts diagrams over the winter  - I'll investigate properly when the temperature rises a little bit more and the garage is a little more hospitable,!

[SteveW]

Is it possible to split the cases without removing the head and barrels?

[Bryanj]

Yes, but you have to remove the camshaft to get enough play in the chain to lift crank

[SteveW]

Yes, but you have to remove the camshaft to get enough play in the chain to lift crank

Thanks for the info, I might attempt my output shaft seal on my 650 then later in the year.

[deltarider]

You could try Wynns Stop Leak, it’s supposed to revitalise seals. Worth a try for about a tenner.

It slowed my output shaft leak on my 650.

I'd do this first ^. I have good results by using an oil that is known to keep rubber parts supple. It's THE major concern as far as our 50 year old engines. You could also put bike on the main stand crank a few turns and... wait. It's more or less the same advise I give when owners 'all of a sudden' have a fuelleak after a prolonged period of inactivty in combination with drained carbs. Open the petcock and after waiting some time, often the seals will swell again.

[K2-K6]

Remove the points plate and you can see the crank seal, as TSD has said it's normally a split the cases job to replace, that's because it's lipped on it's outer edge. First off you need to make sure it's that that is leaking, it could be the crankcase sealing itself. You could possibly get away with removing the seal, if it is that, and removing the lip off a new seal and driving it into place, it may work and for the cost of a new seal it may be worth trying first. However that's not without it's risks, the seal is very close to the crank shells and if you hit those you're in a lot of trouble. It has been done though.

Thought we had a thread on this in the anals of forum. Recall as a successful replacement in situ, but could be wrong 

[SteveW]

Think the previous owner of mine attempted to remove the output shaft seal without splitting the cases and gave up before he did too much damage.
Fortunately mine only leaks very slightly after a run and put on the side stand. When it cools down it stops.

[Laverda Dave]

Remove the points plate and you can see the crank seal, as TSD has said it's normally a split the cases job to replace, that's because it's lipped on it's outer edge. First off you need to make sure it's that that is leaking, it could be the crankcase sealing itself. You could possibly get away with removing the seal, if it is that, and removing the lip off a new seal and driving it into place, it may work and for the cost of a new seal it may be worth trying first. However that's not without it's risks, the seal is very close to the crank shells and if you hit those you're in a lot of trouble. It has been done though.

Thought we had a thread on this in the anals of forum. Recall as a successful replacement in situ, but could be wrong 

There was Nigel, I remember it well but I've just done a search and nothing comes up. I remember whoever tried it used two self tapping screws drilled into the face of the seal to pull it out. They removed the lip of the new seal when replaceing it. I have no idea if it was a success though.

[McCabe-Thiele (Ted)]

I found this old discussion, with links to the US site? http://www.sohc.co.uk/index.php/topic,28589.msg268753.html#msg268753

[Johnny4428]

I remember seeing the replacing of that seal, think it was on you tube. At least the output shaft seal is not a lipped seal like the crankshaft ones.

[SteveW]

My output shaft seal on the 650 is lipped