Inliners International Forums General Discussion Engines Rear main seal leak on 250

Months ago I posted about my rebuilt 250 leaking oil. It pumped out about 1/2 cup during can break-in. At low RPM it didn't seem to leak, but when it was up above 2000 it showed.

I pulled the engine and re-did the oil pan, and because I was putzing around breaking in the engine, I wasn't turning it up, and I thought the leak was gone. I went on a 1500 mile trip and during one segment I drove it at 75-85mph for about 100 miles and it pumped out over a quart, while it wasn't using any oil during the scenic bits. I was whiffed 'cause I hate having something with oil dripping off it unless it's a dipstick.

I finally got around to pulling the engine again. When I inspected the seal, I found a small 'blob' of the sealant that is used between the maincap and block, stuck to the seal where it meets the crank. There was actually some still stuck to the crank as well. I'm hoping this time I got it.

Is the seal installed correctly? They can be installed backwords.Sorry, had to ask.

Sometimes it helps if you post some pics.

Do you have a PCV installed? Valve cover breather?

MBHD

The seal was installed correctly, and the oil was being slung out by the front of the flywheel. I checked the cam retainer both times and it didn't look like the problem. The engine has PCV and a vented cap. No oil was blown out of the cap onto the valve cover. The engine is dry including the pan. It was just leaking out at the flywheel cover.

I'll reinstall this week and hopefully it's fixed.