1983 R100RS Replace Oil Pan & Suction Flange Gasket, Get Oil Pan Mating Surface Flat

It’s time to work on the bottom of the engine.

Engine Block Securely Mounted On Harbor Freight Motorcycle Stand

Engine Block Securely Mounted On Harbor Freight Motorcycle Stand

I replaced the oil pan and the oil pump suction flange gaskets.

New Gaskets-Green Is Oil Pump Suction Flange Gasket

New Gaskets-Green Is Oil Pump Suction Flange Gasket

Along the way, I checked the oil pan to see if the mating surface was flat.  It was not, so I sanded it and now it’s flat. That should go a long way to ensure the new pan gasket does not leak.

Checking For Uneven Mating Surface On Oil Pan

Checking For Uneven Mating Surface On Oil Pan

The gaskets I need are included in the EMC engine gasket kit. I’m also going to replace the oil pan bolts and wave washers with new stainless steel hardware I got in the bolt kit  from “The Bolt Guy” for the RT model since I’m converting the RS to an RT, not that RT pan bolts are different from RS ones.

To prevent the threads of the stainless steel bolts from galling in the aluminum bolt holes in the engine block, I apply anti-seize. However, it’s a lubricant. Since the recommended torque for the bolts is 6 FT-Lbs, which is quite low, if I torque the lubricated stainless steel bolts to that value, I stand a good chance of stripping the threads. So I reduce the torque by 20% to protect the threads.

For low torque like this, I always use my INCH pound torque wrench.

You can read about how I did the work here:

And here is a short video summarizing the procedure.

VIDEO: 1983 BMW R100RS Replace Oil Pan & Oil Suction Flange Gaskets

2 thoughts on “1983 R100RS Replace Oil Pan & Suction Flange Gasket, Get Oil Pan Mating Surface Flat

  1. I have used one of those rubber neoprene I guess it is gaskets instead of the paper one on valve covers and carburetor float Chambers and they work very well

    • Hi Frasier,

      Thank you for your note. I don’t actually like the silicone gaskets, but to each their own. Thank you for sharing.

      I find that oil and fuel leaks are caused by matting surfaces that aren’t flat, so the best solution is to correct the problem.

      Best.
      Brook.

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