Hello all.
I'm basically looking to see if ANYONE has run into this problem. 2008 Heritage softail, K&N Stage one air filter with stock exhaust and Power commander 2. WAS running 100% better than stock. Decided to put in an external breather with Catch can. Went for a 100 mile run. Started off running beautifully. Than all of a sudden it started to stall when I'd come to a stop. Got progressively worst as if the cut down was going way too low. Idle would just drop and the engine would stall. Was pulling out my hair trying to figure what I'd done, and the only thing was the external breather and catch can. So, I removed the Catch Can, and ran the line under the bike to the atmosphere without filter (the tube is dry). Went out for another 100 miles or so at all speeds and the Stalling completely went away. Just can't figure how a catch can would cause that, but evidently it did. Has anyone heard anything like this before?

 

Did your catch can have a vent line on it? If it wasn't vented it would cause stalling by making too much back pressure in the rocker boxes

 

Curious to know what kind of catch can you used .

 

First thng comes to mind, 2008, upgraded the tuner. Did you re-map it as you added?

 

this is the catch can that I used.. Supposed to breath thru the top holes. I'm thinking NOT.

 

Tampa_Fatboy.....Well I didn't remap just for the external breather. Just ran the map with the Fuel Moto map for the Stage one Air cleaner and stock exhaust. I wouldn't think a remap would be required for just the breather. Any way, like I said originally, the problem is solved. I may put a K&N filter at the end of the hose, but will stay away from the can. Just couldn't figure it out. I think that gerald martin may be correct though. Maybe this particular can just didn't breath correctly.

 

No need to remap for an external breather....

I'll bet the catch can, for whatever reason, wasn't venting....

 

I think you are correct. It wasn't venting for some reason.. I may give it a good look-see and see if the holes were blocked or something. OR I may just put a regular filter on it.

 

I have seen catch cans like that, they have a bunch of plastic mesh in them and get clogged up as quickly as you go through one tank of gas. they are far too small. If you use a catch can they should hold at least 5 to 6 ounces of liquid and should also be vented to the atmosphere

 

Agree.. will be going with a filter.