Besides the vent in the transmission that's supposed to help the primary to vent, has anybody ever actually added a vent directly to the primary?

I took the fat boy out today for the first time since early November, and I was only out for about 7 miles and when I got back home there was his major hissing noise and oil dripping onto the floor. After further investigation, I started messing with the stator plug in the case.. As I was wiggling it around which by the way was a source of my oil leak.. I couldn't believe all the air pressure coming out alongside of it.. So I checked my transmission vent, I pulled the hose out to the side and tried to blow through it and I could not. So I took the hose off tried to blow through it and still could not. So I used a rod to clear the hose and what I did find was the larvae of some kind of bug that totally plugged up the hose. No big deal and hopefully that's the end of that but I'm curious if anyone has actually ever put a direct vent into the back side of the inner primary and if so would you mind posting up some pics..

 

I don't know about a Evo but a Shovel has a pipe plug on the back side of the primary, did the fitting with a small braided hose on mine

 

Don't see factory threaded area on a Evo inner, I have also heard Shovel guys drill and tap a hole on the top side above the clutch basket too

 

Thinking of doing that.. it only makes sense to me..

 

Have seen mud daubers do that before. There is no need for a primary vent if you keep that vent tube open.

 

Here ya go! Works great, no issues, only about 10-15 bucks at home depot.




Seriously, It's an interesting topic. It makes sense and has me curious. There are some posts over on the M8 sub-forum. It seems that some have played around with primary venting because of the early M8 oil transfer issues. Might want to snoop around there to get some ideas.

Looks like MoCo even came up with a special kit for venting the primary. The kit is probably not worth while or may not even work for our older evo's , but again might get the creative juices flowing. This is just one post regarding the issue (link below). It's kind of a long post but it shows a few options (including the awesome looking custom one in the pic above).

https://www.hdforums.com/forum/milwa...vent-pics.html

https://serviceinfo.harley-davidson....0_en_US.blaise

Here is an install vid on the above kit:

 

I had a bike here that was pushing oil out the clutch cable adjuster, mud dauber had plugged the trans vent.

 

That's exactly what is was..

 

Thanks for the pic and info... That setup is like having an outhouse in this day and age when we have indoor plumbing...... Yut, sure looks pretty...

 

I think you guys are waaaaay overthinking this. If you're really that concerned, why not stick something like this in the end of the hose? Your goal isn't to create a new vent, it's to keep the one you have open. Unless you close the end of the new vent you create, same potential situation exists. There are tons of sintered bronze mufflers, oil air separators, mesh - anything you can think of just to prevent them from getting in. It's a practically invisible location, you could just zip tie a piece of black screen over the end of the hose.