fiferwd@... wrote:

> I remember seeing something on the forum about installing a power brake
> check valve in series with the breather hose to maintain negative pressure in
the
> crank case. Anyone tried this?

Oh dear, now you've done it - this is the next best thing to "what kind
of oil do you recommend?" I am the brake booster valve proponent. You
can search the message archives for a part number and source; there are
many suitable types. If you can't find em, I have them on my home
computer and can get them for you. I've used this type of valve on big
singles and twins for years to good effect.

Another valve I like (but more spendy) is the Krank-Vent (Google it),
and I presently have one of these on my Bullet. The main benefit of
these valves is reduction of crankcase pressure below atmospheric
pressure; this tends to keep oil inside the engine. There are also some
windage benefits at high rpms but that is not our concern with Bullets, eh.

I have not performed pressure tests myself but have seen results of
tests by people I respect, and they indicate about a 2psi reduction
below atmospheric. My engines do not weep any oil, which is more than I
can say for Bullet's gearbox ;-/ There is no downside other than the
cost of the valve, which is minor if you choose one of the cheaper brake
booster valves. Make sure it's installed blowing OUT!

Cheers
Rick F