Winter is officially here, because when I changed the oil in my 1970 145 on the weekend, the tell-tale yellowish scum was present and accounted for in the oil.

This has me perplexed, because:

a) I use Mobil 1 synthetic oil, and Volvo oil filters, so there is no question of oil integrity;

b) I drive about 20 minutes one-way every day to work down a highway and then a freeway, so there is no question of that venerable B20 workhorse not being sufficiently warmed up every day;

c) I often drive for extended distances on the weekends, for several hours at a time, so Bjorn has plenty of opportunity to get out and stretch his legs.

Last winter I took off the flame trap and that helped a little, but not completely. I was thinking of taking off the entire hose assembly this winter to see what would happen.

Any experiences with this malady?

Ross