Anyone Know What This Machine Screw Does?

[J6G1Z]

I bought this modified side cover & oil cooler off of eBay from a bike salvage yard.

I'm concerned about this machine screw & its function. It appears to intersect an oil passage on the inside of the case. I don't know if it blocks off the oil passage completely, or just restricts the flow. I'm assuming that it is required for the oil to flow through the cooler correctly.

If anyone knows what I'm looking at here, please let me know.

Thank you
J.

[J6G1Z]

I talked with the salvage yard where the cover & oil cooler came from & they assured me that the Ascot that these parts were removed from was a good runner & that the engine was not siezed.

Unfortunately they didn't know much more than that though.

Thank you
J.

[Thack]

My guess is restriction. Oil going through an oil cooler too fast doesn't cool very well. Then again with oil pressure at 4-5 lbs., it may be to keep up the pressure for the entire system. Have you backed it out to see what it looks like?

[J6G1Z]

No, I haven't messed with it yet. I'd just like to verify what it is there for. It's not drilled exactly centered with the oil passage & favors one side slightly. I think you can see it in pic #2. If it serves a worthy purpose... I would like to remove it & exchange it for a flush mounted machine screw that doesn't stick out.

Thank you
J.

[Thack]

What is the hole above the screw for? what goes in there for lubrication? Does the passage below the bolt just drain into the sump area?

[J6G1Z]

What is the hole above the screw for? what goes in there for lubrication? Does the passage below the bolt just drain into the sump area?

That's part of the problem. I don't know what or where any of the passages go to. I've never had an Ascot engine apart yet & don't know the lubricating flow path.

If all goes well, I have another local Ascot enthusiast coming over this week end to have a look at it. I'm hoping that he will know what is going on here.

Thanks
J.

[Thack]

I'm guessing the hole above the screw may be for the shift shaft. Here's a diagram. Maybe it will help you.

[J6G1Z]

I was looking at that diagram earlier & was thinking that it might be the balancer shaft. The oil passage is the furthest forward in the side case.

The clutch operating link is at the opposite end.

I looked at it again today & the screw blocks the oil passage & seperates it into two different passages. It's definately been done to split the flow for the cooler.

Thanks
J.

[Thack]

I think I solved the oiling path for you. See the two pics with labeling. The oil from the pump and oil filter is pushed to a pressurized area which splits into the crankcase and the clutch cover. The pressurized area supplies oil to the shift shaft and transmission via the little oil jumper. In the cover, the pressurized area feeds oil to the crank, upper end and the balance shaft.
The screw in the pic above is right below the crank oil feed galley. I wouldn't restrict oil there or anywhere below the cam oiling feed. Maybe it will be fine.


EditI see now that the oil from the pressurized area goes out to the oil cooler and back into the oil system about the cam & crank oil feed galleys.

[Thack]

Crankcase side.