Oil leak, 2007 Griso 1100

[Mark_Z]

My bike has developed an oil leak. It is coming from the left side valve cover. The guy that worked on it last tried to fix a similar leak using rtv cement, which worked for a while, then began leaking again. I took off the valve cover, got the seating surface really clean, put on a new gasket with no cement, then got about 3-4  months with no leak. However, the leak is back. What do I do ?
,

[Chuck in Indiana]

The first thing I'd do is make sure the valve cover is flat.

[Mark_Z]

The guy that worked on it last said the covers weren't flat. Could he have cranked down too hard on the bolts and bent the covers? He also allowed as how he had a machinist friend say that he would be unable to machine them flat. Sounds to me like I in the market for new parts, although I think I will crank down on the bolts some more. Couldn't hurt.

[oldbike54]

The guy that worked on it last said the covers weren't flat. Could he have cranked down too hard on the bolts and bent the covers? He also allowed as how he had a machinist friend say that he would be unable to machine them flat. Sounds to me like I in the market for new parts, although I think I will crank down on the bolts some more. Couldn't hurt.

 Yes it could hurt . Unless they are really warped they can be ground flat with a piece of plate glass as a grinding surface , and some 200 grit emery paper followed by a bit of grinding paste . Use a figure 8 motion . It is much less work than fixing stripped out threads in the cylinder heads .

 Dusty

[fotoguzzi]

  I think I will crank down on the bolts some more. Couldn't hurt.

YES it can.. you risk stripping out the threads in the head, stand back, do you know how to insert a helicoil?

[Chuck in Indiana]

Yes it could hurt . Unless they are really warped they can be ground flat with a piece of plate glass as a grinding surface , and some 200 grit emery paper followed by a bit of grinding paste . Use a figure 8 motion . It is much less work than fixing stripped out threads in the cylinder heads .

 Dusty

What Dusty sez..

[guzziownr]

These are twice the price of the stock gasket.  Makes you wonder...

http://www.mgcycle.com/index.php?main_page=product_info&cPath=170_174&products_id=4634

[pete roper]

These are twice the price of the stock gasket.  Makes you wonder...

http://www.mgcycle.com/index.php?main_page=product_info&cPath=170_174&products_id=4634

And worth every penny! For some reason the later model, post V11, bikes have this chronic problem with spitting out rocker cover gaskets! Its nothing to do with flatness, the surfaces can be absolutely true and they'll still do it. It must be something to do with the newer rocker cover design.

Anyway, if you get a pair of those Valpollini gaskets from MG all your problems will be over.

pete

[Lesman]

I bought a  set of silicone gaskets for my Quota. I wish I knew about these gaskets.

[not-fishing]

Yes it could hurt . Unless they are really warped they can be ground flat with a piece of plate glass as a grinding surface , and some 200 grit emery paper followed by a bit of grinding paste . Use a figure 8 motion . It is much less work than fixing stripped out threads in the cylinder heads .

 Dusty

Wow thanks Dusty, my Griso 1100 also has the reoccurring leak in the valve cover and I wear red suspenders so........

Just like grinding a mirror for a reflector telescope.

Mark

[oldbike54]

Wow thanks Dusty, my Griso 1100 also has the reoccurring leak in the valve cover and I wear red suspenders so........

Just like grinding a mirror for a reflector telescope.

Mark

 Grew up on old Brit bikes and we were poor  Sugar paste  makes a decent temporary thread locker also 

 Dusty

[Mark_Z]

And worth every penny! For some reason the later model, post V11, bikes have this chronic problem with spitting out rocker cover gaskets! Its nothing to do with flatness, the surfaces can be absolutely true and they'll still do it. It must be something to do with the newer rocker cover design.

Anyway, if you get a pair of those Valpollini gaskets from MG all your problems will be over.

pete

As always, Pete, you are the man. I will get a pair and give them a try.

[jreagan]

I also have a leak on the left for my B1100.  I'm due to check the valves anyway (they aren't loud enough) so I'll replace the gaskets with the Valpollini ones while I'm doing that.

[Mark_Z]

As always, Pete, you are the man. I will get a pair and give them a try.

A follow up to my original post. I ordered and received a pair of the gaskets that Pete recommended. So far, so good. Now for an observation and a query. After scraping off the old gasket material, I found the solvent DMSO did not remove the last traces of gasket, but that the solvent xylene, chemically very similar to gasoline,  did a wonderful job. My query then is this: can exhaust or intake gas get into the valve cover space, maybe because the valve guides become worn after a time? If gas fumes can get in, even in very small quantities, then the fumes might swell the material enough to cause oil to get out from the valve cover. I would also note here that the gaskets that were on the bike when I bought it didn't stick to any of the sealing surfaces, and as a matter of fact, I was able to re-use them after inspecting the valve clearance, and no oil leak after 're-use These facts lead me to believe that MG changed the gasket compound to something that will allow leaks.

[Chuck in Indiana]

I think you're over thinking this.. 

[boatdetective]

Yes it could hurt . Unless they are really warped they can be ground flat with a piece of plate glass as a grinding surface , and some 200 grit emery paper followed by a bit of grinding paste . Use a figure 8 motion . It is much less work than fixing stripped out threads in the cylinder heads .

 Dusty

   Absatootley. Very easy.  I tend to use wet or dry sandpaper and spritz it with WD-40 as a lube (so the aluminum doesn't load the paper. I'd recommend starting with a light grit- aluminum cuts pretty easily.

As mentioned, a piece of plate glass would be a great flat reference. I tend to use the bed of a tablesaw.

If worse comes to worse, you could get a set of silicone gaskets- should have plenty of "squish" to make up for irregularities