Topic: Oil magnet funk. Cb750f

[catsoup]

Question for the group. I just changed the oil on my 1978 cb750f (26500miles) it had been longer than usual, both in miles and time. Maybe an extra 500/1000 miles / 12 months while I was away from my bike. I had put harddrive magnets on my filter last time to catch any metal that might be there.

This is what they looked like when I pulled the filter.




(the water you see is from cleaning. It didnt come out like that  )
Pretty thick black funk. I wiped it off and dissolved it - in both instances it was just black sludge. Nothing shiny, nothing gritty.

Is this a sign of something specific or is this to be expected?

[seanbarney41]

I would not worry about it unless there was nasty noises or bad performance involved.  I remember changing my oil and filter once after running 110-115mph for about 50 or 60 miles...terrifying amount of stuff in there, but that engine ran fine for 1000's more, and is still running fine as far as I know

[b52bombardier1]

That is a normal amount of metallic peach fuzz on the magnet.  I get about the same on my CB500's magnetic drain plug and would not worry.

Rick

[Don R]

 Watch between the folds in the filter for silver pieces. I've had scary amounts in my dragster's engines and yet it looks great inside. The magnet is doing it's job as is the filter. When there is a nut, bolt or washer on the drain plug magnet, that's bad.