Look at the center of the gas cap in the picture, you'll see the orangish flat rubber diaphragm with a hole in the middle. What causes the tanks to hold the excessive pressure is when this small hole gets off center and doesn't allow the proper ventilation while riding.
I'll say it again, if you have a later model 1500 with Honda engineered vent system with red vent hose out the top of the fuel cap, you should not get the vacuuming effect after riding or when you open the gas cap.
Since purchasing my bike 3 years ago and putting on about 30K miles, keeping the vent hole aligned has eliminated the vacuuming (or boiling) effect on my bike.
If you find the vent hole is aligned in the gas cap then check for a pinched line in the red vent hose.
For me this fix eliminated the hard starting after warm.
This fix could possible prevent the failure of other components in the fuel system such as the fuel pump and petcock from the stress working outside their limits against the extra vacuum pressure?
|File Type: jpg
||image.jpg (166.9 KB, 33 views)
Last edited by 1potter1; 10-11-2015 at 08:55 AM.