tank venting issue?

[pitbull]

a couple weeks ago I put a post up about a hard starting problem, along with some bogging down while riding on my 01 900.

I received some good suggestions and after swapping in a new fuel pump filter and throwing in some new spark plugs, the hard starting problem has been solved for now.

However, I'm the bike is still bogging down while riding. The bike wants to stall and bogs down if I let off the throttle and I'm kinda stumped.

Yesterday  I pulled the bike out of the garage and it was sitting in the sun for a short period, in the driveway, while I was doing some stuff in the garage. I started to hear a really high pitched whining noise and realized quickly it was coming from the bike. I opened the gas cap and the noise went away immediately.

Today I pulled the bike out again, into the sun to try and replicate the incident and sure enough it started the high pitch whine and as soon as I opened the gas cap it immediately stopped. The bike only has about 1/3 tank of gas in it.

Any thoughts and/or suggestions would be much appreciated.

[Ddan]

The vent is clogged.  Check the hoses under the tank, blow through them to make sure they are clear

[ducpainter]

The vent is clogged.  Check the hoses under the tank, blow through them to make sure they are clear

Not so sure.

The cap has a 2 way vent...in and out...and they use separate flapper valves.