Having pulled my hair out a few years ago over a different cause but the same result I can tell you why the bike was acting that way. I can't say why the catch can wasn't breathing adequately but I can tell you that when there is a restriction of airflow at the breather bolts sumping is the result. The oil pump doesn't scavenge properly when the top end airflow is restricted. Once you put a few miles on it the amount of oil collecting in the crankcase starts to drag on the crankshaft causing sluggish throttle response and stalling. My issue wasn't catch can related but because of the trouble I had with restricted air flow I don't use one, i have the hose routed to the underside of the frame and haven't given it another thought.
Thank you. I was thinking that it might be something like that. Just couldn't figure out why removing the catch can stopped the issue,. I ordered this one from DK, and it's a much better build, so I'm hoping it will work. I agree with you that just venting to atmosphere would probably be totally what I need, but I just don't like that line on the side of the engine. Looks out of place, and there is no way to hide it. I know, it's ****, but aren't we all a bit **** when it comes to our bikes? lol.
I ran my FB with a DK Customs catch can for awhile and it did fine. But I got tired of emptying it of what was mostly water after every 2nd or 3rd ride (just to be safe). Since then I just routed the breathers to atmosphere down under the bike. I've never noticed a drop of anything (oil or water), from the hoses and now the only time I take the AC off is to recharge the K&N filter.
To catch can Routed to atmosphere
Hoses running down between rockers and then along from to the swingarm.
11-12-2020, 12:04 PM
