Vapor Lock... Need Advise

Energy One

montana

Active Member
I have an 08 Mastiff. I've had intermittent issues with vapor lock since day one. I took off all of the California emissions crap and added a vented gas cap. I completely drained my tank and refilled it just to have a fresh start. My bike runs fine for the first 65 miles I put on each full tank. After 65 miles it chugs, hesitates and sometimes stalls on acceleration from a dead stop. Once I get going (and don't stall), the bike runs fine until I have to stop again. If I take my gas cap off completely, I have no issue... but not smart to ride without a gas cap. Any advise?
 

seatmaker

Well-Known Member
I removed the vent, but still have to crack the cap after a long stop. Guess I just got use to it. Doesn't bother me.
 

BBChopper

Supports 2 Disabled Vets
Troop Supporter
I removed the vent, but still have to crack the cap after a long stop. Guess I just got use to it. Doesn't bother me.

X2

It’s probably the cap remove the guts in the cap and try it! I had the same issue and while riding with Raywood it happened he came back a said loosen the cap and when I did you could hear the air rush in!!!:2thumbs:
 

montana

Active Member
Thanks. I also removed the guts inside the gas cap the day I bought the bike. I didn't realize how common the problem is. I guess I'll just deal with it until I find a solution.
 

Five Five

Well-Known Member
X2

It’s probably the cap remove the guts in the cap and try it! 2thumbs:
Hey Russ....BBChop recommendation is where I would start....My buddy had the same problem he drilled an .030" pin hole in the cap works great....dont leak either...:up:
 

Raywood

The Pirate
Staff member
Calendar Participant
Troop Supporter
Thanks. I also removed the guts inside the gas cap the day I bought the bike. I didn't realize how common the problem is. I guess I'll just deal with it until I find a solution.
Even though you removed the guts out of the cap it still may be clogged with glue or something.

Look on the side of the plastic piece under the cap and locate the vent. Then wrap your lips around the threads and blow with your finger over the vent and see if it's venting.

:D:cheers::D
 

Brew

Troop Supporter
Damn Ray, are we giving lessons on blow jobs now...:rolleyes::roll::roll::roll:
 
Last edited:
Top