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Discussion Starter · #1 ·
Has anyone noticed a strong fuel smell as the gas goes down, It seems like when I fill it up I don't smell it, but then when the first bar goes down on the fuel gauge I start noticing the fuel smell getting stronger. I didn't notice this at the first 1300 miles, but after I took it in for service it really got strong.
 

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If this only happens very occasionally, it could just be unburned fuel in the exhaust. If it happens a lot, or it is very strong, it could be a cracked fuel line, although there is so much pressure in there it would be coming out pretty fast. It's be worth lifting the tank and starting her up and see what is happening under there though.
 

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I've been experiencing the same thing. I wonder if it might be coming from the crank case breather tubes after doing my stock air box removal.
 

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INTREPER said:
What is the "PAIR" system?
The PAIR valve is used to burn off fuel from incomplete combustion that occurs during deceleration in gear. It works like this:

When you open the throttle on your bike, manifold vacuum drops off since air is entering through the throttle bodies. This air mixes with fuel that is burned in the combustion chambers, more or less completely. When you let off the throttle, particularly in gear, the throttle plate closes, restricting airflow to the combustion chambers, and the manifold vacuum goes way up. This is particularly the case when coasting in gear since the engine is being pushed by the rear wheel at speeds above idle. Since the throttle plates are closed, a high vacuum is developed. This vacuum pulls fuel into the engine, but the mixture is too rich for it to burn. It's dumped unburned into the exhaust system.

This is where the PAIR valve comes in. The valve is controlled by manifold vacuum. When vacuum increases (pressure decreases), the valve is pulled open. Fresh air is drawn in through the PAIR's air filter and fed into the exhaust port of the cylinder heads. The source of fresh air is from the airbox. That air provides the right mixture to spontaneously ignite the hot unburned fuel exiting from the exhaust valve.

Hope this helps.
 

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Discussion Starter · #7 ·
It happens all the time, I know when I pull into my garage from work, I can really smell the gas. Again it seems like only when the tank is not to capacity. When it is low really get the smell.
 

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vpatrick said:
It happens all the time, I know when I pull into my garage from work, I can really smell the gas. Again it seems like only when the tank is not to capacity. When it is low really get the smell.
Hmm, Could it be the gas/fumes in the tank heating up and expanding?? there must be an overflow or vent for the tank right?? This would explain the not smelling when full... the liquid will not heat and or expand as quickly so it would not happen with a full tank.
Try going for a quick ride in the evening when the bike is fully cooled down and see if it is there with the empty tank afterwards....

Sledzep
 

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I seem to notice gas fumes when my tank is low on fuel, just filled up or if it has been sitting in the hot sun??? ::) :doorag:

Sled, You may have hit the head of the nail! :bigthumbsup: :doorag:
 

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I have the same problems with the petrol fumes , when i notice them i put my nose down near the fuel cap and thats where it is coming from , and when you push down on the cap the smell gos away,so im guessing the seal isnt that great, im going to get them to check it out when i get my first service done . cheers scott
 
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