Changed oil and oil filter mobil 1 HD new 5 micron oil filter on 2 bikes Fatboy and Roadking during the week. Going away today for two days and checked oil in bikes after a short ride and found froth on top of oil in both bikes. The only difference being the new filters. Will have to go out and buy 10 micron filters if available or replacements before trip. Any suggestions?

 

"Froth" doesnt mean a thing, your oil when returned to the tank many times will churn the oil up. No big deal. The new 5 micron rating has little meaning, its not an absolute rating, its an "average" rating. I have seen lower rated micron filters pass larger particles through them than filters with a larger nominal micron rating. HD filters never have been the best of quality anyway. If you want a quality filter that is really worth $10 then pick up a K&N oil filter.

 

I am aware of these facts but two things have changed. A different filter rating and exessive foming that wasnt there before. I will purchase the K&N filter

 

Fitted K&N filters and oil appearance back to nornal, must have something to do with HDs finner filter.

 

How much was the K&N? How much is your HD shop charging you for HD filters? Just curious about the price comparison...

Mac

 

As mentioned, some foaming is normal because of the higher velocity of the Mobile 1 oil recirculating through the system along with traped air in the system after the oil change.

Trapped air and/or overfilling will cause foaming, not the filter.

The K&N is a better filter and is easier to change, but will not prevent foaming. The smaller the filter micron rating the better the filter, especially with synthetic oils. The micron size has nothing to do with foaming.

Give it a few miles then check it. The foaming wont hurt anything.

Steve

 

Hi Steve, K&N filter $30.00. HD filter$32.00 Aus dollars. I buy all my parts from USA filters I buy 12 at a time the last lot of HD was about $11.00 US ea. I have just orded 12 K&N but not received statement yet. Should be about $10.00 ea.

 

You were sure to get the KN-171 part #right? Great filter, probably best on the market by a wide margin. Most filter media, about 3 times the amount of a HD factory filter.