C15 Stopping the leaky sump, or at least trying!!

[Jazzman]

Hi guys,
I decided to tackle the dripping sump for the third time, only this time I made a few discoveries.
Firstly, I though it might be a good idea to lap the face of the cover and filter plate.
To my horror and yet no surprise to British so-called engineering, the sump cover was not remotely flat, if ever it was, given it's just a simple pressing.
Having lapped it on a flat surface with emery cloth, and expecting it to be more or less bright all over, the result was very disappointing. The four bolt holes were bright enough, but on offering a straight edge up to them you could could clearly see sunlight beaming through the beautiful arch between them.
Anyway I worked on it for quite a while till I was satisfied I was somewhere near a flat surface.
Oddly the filter plate was not so bad and was quite useable as is.
I've not used paper gaskets when reinstalling, instead I've put it back with high temperature gasket maker, and will see what happens.

The other thing I discovered was the frame pinching the side of the sump cover. A couple of weeks ago I went round tightening anything that would allow the crankcase to leak. In doing this, I found the engine mounting bolt behind the sump was lose so tighten it up, which in this instance stopped a leak...but when I went to take the sump cover off today it wouldn't move because of the frame pinch. Only when I released the mounting bolt could I remove the sump cover.
What I've done to solve this issue is to lever the frame away from the sump and place a spacing washer on the kickstart side of the engine mount, between the engine and the frame. I've now been able to tighten the mounting bolt and still be able to mount the sump cover back on with ease.
I don't know whether there should be a spacer between the engine and the frame on the kickstart side, but wonder now if the pinching was aiding the sump cover leak??

Cheers,
Mike.
             

[rhyatt]

https://draganfly.co.uk/shop/98784/spacer-1596930028/#40-4080

on the later frames - yes

[Tigerfeet]

From memory the spacer is 1/8" thick.

[Jazzman]

Thanks guys.
As it happens the spacer I fitted was quite thick, certainly more than an average washer, so it looks like I have it about right.

As always, much appreciate the info and ideas.

Cheers,
Mike.

[Jazzman]

And the drips continue!!
I've reduced it a bit, down to maybe 4 to 5 drips a day, but for me 4 or 5 too many.
I can tell how much is leaking by placing a tell tale piece of dry cardboard underneath, the diameter of the wet spot tells me how much has leaked.
I don't know if I'm being bloody minded about it, and I can hear people saying a few doesn't matter, but it matters to me.
Meeting faces are not designed to leak, otherwise the makers would leave a hole for it. The truth is the engine should be bone dry on all meeting faces that contain oil.

Anyway, ever onwards in the quest for my bike to have a dry night.

Cheers,
Mike.   

[Greenfield]

The pressed steel sump plates aren't flat. Make sure all surfaces are thoroughly clean and free of oil. Use a good quality gasket on both sides of the filter with a smear of RTV on all surfaces. Don't overtighten the nuts, just enough to see the RTV start to squeeze out of the joints. Leave overnight for it to cure before testing. Its worked for me.

[cdsdorset]

Is the leak coming from the plate or through a thread. Get some ring oil dye and a uv torch and make sure you are looking in the right place.

[Daz]

Are you certain the leak is coming from the sump plate?
A customer recently brought his C15 to me with what appeared to be a leaking sump plate, he'd tried everything to seal it. I got it up in the air, cleaned everything off and waited for the oil to appear. It was coming from the outer timing cover and running down onto the sump plate and studs. It had been wet sumping and oil was passing through the little hole in the inner timing cover that's there to draw the oil back into the engine.

[Jazzman]

Thanks for your thoughts guys, always appreciated.

This evening I took a real close look at it with a very bright light. I think Daz might be nearer the problem, in that I could, or at least think I could,  detect a very small amount of oil above the sump joint.

The thing that's throwing me off a tad is the fact that as I've worked on the sump joint so the oil leakage has got less and less, now only appearing on the rear nut nearest the kickstart.
Anyway, I've thoroughly cleaned the shoulders of the sump above the joint, and will take another look tomorrow.
Incidentally I did check to see if it was wet sumping a week ago when I was replacing the oil pipes. All I ever get when removing the sump cover (four times now) is little more than half a cup full; not enough me thinks to be overflowing into the timing cover and leaking. BUT...I did detect oil above the sump joint??

Let's see what tomorrow reveals. 

Mike.       

[rhyatt]

it took me a few goes on my C15 to get the inner to crankcase dry and then the outer to inner dry , but i succeeded in the end

[Jazzman]

Well there's one sure thing, I don't give in easily.
So by hook or by crook etc etc.