Wet sump check valve machined into timing cover?

998cc said:

Cliffa, here is a photo of the modified case. I pulled the trigger and had mine done. The ball and spring are smaller than the diameter of the bore. That wire you see in the bore is merely a keeper until the cover is reinstalled. Also, the conical oil pump sealing washer has been replaced by a large-ish sectioned O-ring; it seems when the engine is stopped, the ball mates up with the O-ring to make the anti-sump seal.


View attachment 14117

Cheers!
~998cc

Click to expand...

Hi 998cc,
Sorry for the delayed reply, and thanks for posting the pics. As you can see earlier in the thread kommando had offered to do my case and oil pump. So as I was going to London for the weekend, I whipped off the cover, but hadn't spotted something blindingly obvious...



I had never noticed this bump before, so it was quite a surprise that when I got the cover off a small plunger fell to the floor. Some clever person had built up the bump with weld and had the cover machined for a plunger al-la MkIII ! It also has a MkIII oil pump and seal. Anyway, I sent the pump off to kommando, and he has machined both sides and supplied matching X rings. And done a very nice job on it. The timing cover hadn't been drilled, but I took a slightly different approach when drilling it as I didn’t have a bit long enough. As the hole at the gasket face is oval anyway, I came in from that side and then to smooth the flow a bit I ran an end mill straight down to remove the resultant peak (not really necessary I suppose).

Some more pics..







all the best,

cliffa.

Cliffa, That's an interesting find on the timing case! The X-rings in the oil pump seems more logical than the O-rings. Will see how the O-rings hold up in mine. After reassembling the timing case, I filled the oil tank and let it sit for a week prior to starting the engine. I noted zero change in the oil level in the tank. Yesterday, after initial start up and anxiously awaiting return oil flow, I took it out for an easy 30 minute ride.

Also installed the Tri-spark this week. I really hope it does not fail as others have. The bike is a dream to start now; with only a moderate push of the K/S lever past TDC, she lights right up!

Regards,
~998cc