'91 EVO Breather Gear

[myt evo]

94, are you sure it's an 1/8 of an inch?

[94flhtcu]

Hey, MYT EVO... It's been a few years, but I THINK it was 1/8".

It MAY have been the next size larger than the hole, but I'm pretty sure it was 1/8".

If anyone does this, check first to be sure you have the right diameter drill bit.

Wait a minute... I'll bet you've done this...

[Stubby3492]

Originally Posted by botzman

Hey all,

Opened the cam chest. No pieces in the bottom, breather gear in perfect shape as well as washer. Im stumped. Are there any plastic gears in the oil pump assembly? I do plan on replacing the lifters at this point. Thanks for your time guys. Mike

I know this is an old post, but I just thought I would comment in case some else has this issue.
The plastic pieces that you are probably from a plastic oil baffle that is inserted loosely in the breather pipe in the cam chest. when I took mine apart, mine had a few pieces of it in the cam chest as well. I don't know if this part is neccesary or not, but I replaced mine.
It is basically a small set of plastic baffles that is supposed to separate the oil in the breather out of the oil/air mist. It is not shown in my Harley repair manual, but it is shown in the dealer parts book up to '92.
They were only used up until '92 with the case breather. In '93 they switched to the head breathers and discontinued the oil baffle.

Hope this helps someone.

Stubby

[botzman]

Stubby,

Thanks. At least I have an answer now to what it could be. I was baffled. Literally. Botz

[Stubby3492]

Hi again botzman,

Apparently this little plastic oil baffle in the parts book is called an air/oil separator. It is supposed to keep oil from spewing out the crankcase breather, but I rode mine without one for about 400 miles and I didn't notice any difference.
I picked one up at the dealer and the next time I had my cam chest opened, I put it in.
I couldn't find any pictures of it, but the Harley part number is HD-25329-91, and it costs about 3 or 4 dollars.

cheers
Stubby

[evoKENevo]

I was going to start a new thread to give my opinion of the new S&S reed type breather valve installed while I was in my EVO gear-case/cam-chest the last time to replace my lifters. But, this seems to be as good a place as any to tell you I'm really impressed with the way it practically eliminated the Evil Evo Oily Blow-By. In fact the few occasional little speckles/streaks of oil I find on my oil tank after a long ride at "sustained high-way speeds" etc might just be from my not having changed the o-rings in my push-rod tubes...noting that when I installed the new S&S lifters (with travel limiters making them kind of finicky) I had to re-adjust my push-rods 2 or 3 times to get things just right (after installing new 0-rings) and there's little if any sign of wet-oil (so to speak) in my air filter or on the inside of the filter cover after several thousand miles now.

The new breather valve is all metal...and a no-brainer to install...with no timing marks etc to be concerned with. Just pop the old one out and pop the new one in with just a tiny spring on the end to hold it in place against the nose cone.

Rating at least 3 outta 4 of these ---> in my opinion.

[myt evo]

Thanks evo for the info. I replaced my breather gear before the S&S reed type breather came out and also replaced the umbrella valves. I had started a thread quite some time ago to see if anyone had used it but never received any responses. I still have a few parts left to purchase for my project before I really dig into it and thanks to your critique of the reed valve it will be one of my purchases.