Just bought a BSA B25 and stripped it down for a service, on inspection I found quite a lot of sludge/carbon in the oil tank strainer, is this normal?

 

Don't think its dirt as the bike's never been offroad

 

When I collected the bike it ran fine,

 

All the bikes I’ve previously owned have always been clean

Edited March 22, 201610 yr by monty_jon

Perfectly normal on a bike that has had way less oil changes than it should... Considering their reputation,not a wise engine to pick on for abuse.

look on the brightside.. it  was in the trap.. clean it all up put fresh cheap oil in and run for 1 hour, make sure the oil is returning to tank than empty it out clean it up again and run proper oil for 5 hours ( two trials ) between changes..

Edited March 23, 201610 yr by totalshell

look on the brightside.. it  was in the trap.. clean it all up put fresh cheap oil in and run for 1 hour, make sure the oil is returning to tank than empty it out clean it up again and run proper oil for 5 hours ( two trials ) between changes..

 

Yes, thats what I have done, did it for 15min with some cheap 20/50 & engine flushing fluid

 

And just done it again after an hour on 20/50

 

Sounds fine, but I was just worried about the big-end as they are quite a fragile engine!