MY14 Standard and SP question Fuel Cap

Anyone with the above MY14, Honda state they have a new fuel cap and seal to improve venting.

Mine builds up what appears to be a vacuum, so on opening the cap to refill, every time there is a whooshing sound, but there are no running issues associated with normal vacuum lock.

Then after running bike, for about an hour after switching off engine, you can hear all kinds of gurgling sounds coming from the tank around the fuel cap area or within the tank, eventually the noise slows then stops.

The dealer checked it at first service and could find nothing wrong, ie pinched hoses etc. and the bike runs fine.

Anyone with a MY14 noticing the same issues?

Thanks

 

It's fine Honda did issue a notice to dealers saying this behaviour is normal.

 

New Model Information



CB650-CBR650-14YM CBR1000RR

A new design of the petrol tank FUEL CAP on the 2014 CBR1000R, CB650 and CBR650, can result in an unusual noise.

It now incorporates two One-Way valves (one for Positive pressure and one for Negative pressure). They are incoporated inside the Fuel Cap to keep pressure inside the petrol tank within a specified range, to reduce emissions and to prevent fuel leakage in the event of the bike falling over.
During normal operation it may be possible for the owner to hear a whooshing/hissing sound when they open the Fuel Cap, this is perfectly normal and does not indicated a fault with the tank breather system, just the release of air due to a slight difference in internal pressure.

Please make sure your Sales and Service departments are aware of this information so they may reassure any owners who report this symptom to them.

See next page for Technical Explanation.

Breather Seal



Negative Pressure Positive Pressure
Valve Valve



Positive pressure valve:

When the internal pressure is increased over a stipulated value, by fuel vapour or similiar from aggitation or heat such as sunshine , the positive valve opens to release internal pressure from the breather until the internal pressure returns to the stipulated value.



Breather Positive -Pressure Valve OPEN

Negative-pressure valve:

When the internal pressure decreases below the stipulated value as the fuel level drops, the negative pressure valve opens to allow outside air to enter the fuel tank.



Breather Negative-Pressure Valve OPEN

 

It's MrB ! I'd trust anything he said ! Well within reason

 

Thanks Mr B, just a bit of a shame that my new pride and joy sounds like its got indigestion every time I park it

 

Danny on here has the same on his SP and i straightened all the breather hoses..