Vintage BMW Motorcycle Owners

While I'm here, is it wise to flush the motor? I'm thinking an annual flush might help keep the slingers clean and wash away any other debris, or, perhaps, it might do more harm than good?

Never heard of that. Imagine, though, by trying to flush things you push some debris into the lower rod holes which feeds to the bearings or maybe plugs the hole to the bearings. The stuff that is trapped in the slingers is out of the way and will no do any harm...not worth stirring things up.

I understand that the low pressure oil pump shoots a stream of oil onto the spinning slinger disk. The oil then is slung out to the outer edges/cup. The heavy particles are compressed into the cup...the oil builds up or stacks up and the top edge of that oil falls into the rod bearing holes.

IMO it's best to leave things alone.

Kurt,
I'm thinking it would help prevent buildup in a new motor where there isn't much debris to begin with. I believe the procedure is to add or replace about 16oz to oil, run it up to temp and then drain it all. By the description, it SAYS it works. Here's a link to Amsoil's version:

https://www.amsoil.com/shop/by-product/ ... SEQAvD_BwE

I'm getting close to my first oil change on the new motor and am mulling this over.

Brian

All I can say is that I've never heard anyone mention this approach before. Your engine...your choice. Give it a try and report back in 40K miles!

Plunger, I wont put that snake oil in a modern engine. Why put it in a vintage engine. Says its good for engines and automatic transmissions, there is a big difference between the two and there make up. If you change the oil every 1500 miles and drop the oil pan once in a while to clean it out. Would be better. But.......

twocams

While I'm here, is it wise to flush the motor? I'm thinking an annual flush might help keep the slingers clean and wash away any other debris, or, perhaps, it might do more harm than good?

Anytime I have heard about “engine flushing” especially with an older engine, it has ended badly. I had a friend who had a slant 6 valiant, and engine known to run literally forever. He decided one day it was time to do an engine flush, which he did. Ten days later the engine locked, mains and rods torn to shreds. Flushing loosened all the gunk just fine, only to deposit it on running surfaces and that was the end.

Icarus

I actually don't know enough about and wouldn't bother to flush my old '69's engine however it is close to 50 years old so not a new motor or new engine build described.

However... I have a marine big block (454) out for complete rebuild and refurbish right now that is very close to being completed.
As part of my 2 year warranty it stipulated that after initial start-up and running the engine, all oil and filters have be changed at no more than 20 minutes runtime. 20 minutes!
After that just regular routine servicing. I guess that's almost the description of a "flush"?

But the engine does have filters, our old bikes don't.