Everytime I start my bike up I get a strong whiff of petrol which doesn't seem to go away, I can also smell it when sat a lights or in traffic. Iv checked for leaks and nothing, recently I replaced the fuel filter and cleaned out the k&n air filter which was filthy.

In always assumed the bike was running quite lean due to the pops through the exhaust upon deceleration. But wasn't ever sure dye to the smell.. Anyway, after cleaning the airfilter I'm getting what I can only describe as soft back firing whilst at idle through the exhaust.

I guess what I'm asking is what is going on, why is my bike stinking of petrol so much, where has this idle issue come from and what can I do to remedy my woes?

 

Both the popping and the smell of fuel in the exhaust are textbook examples of machine running lean.

 

To get to the bottom of the issue you need to do some carb work. it's not super difficult, but it is somewhat exacting.
For starters, how long has the bike set for any given time. It doesn't take too many months for the gas to start to gunk up.
Also, if that doesn't apply to you, if you ran the bike dry and had to go to reserve, if there was stuff in the bottom of the tank, it will get in your fuel lines.
Thirdly, how long has the bike give the symptom? It may be that it's been like that since you've owned it and a thorough cleaning of the carbs is in order.
Lastly, it could be that your pilot screw simply needs adjusting.

 

The bike is a daily runner, never sits for more than a day at a time. The smell and the popping I guess the bikes always done it since iv had it (8 months) in that time I have shortened the muffler and the pipe so guess that's extra air flow.

So looks like I'm pulling the carbs for a good clean and sync?.. And to richen up the mix

The pilot screws are the cross head screws, one on each carb correct? Just use these to richen or should I adjust the jets and needles

 

There is one pilot screw for each carb. On the US models, the heads are D shaped. They are on the bottom of the carbs and are the only brass screws on the exterior of the carb.

 

And you either need the carb adjusting tool with the d-bit and the 90 degree angle or you need to remove the carbs and flip them over to turn the screws. You can try to make a straight slit to the screws with a dremel if you got steady hands but I'd recommend getting the adjuster tool.

 

These pilot screws are the ones il use when doing a carb sync aswell aren't they?

I have a UK model which has a cross head to the top of these brass screws, also there is one on every carb so i have 4 in total, unfortunately one of mine is stuck (far right carb) and so the cross head top has broken. So maybe the dremel route after all.. What would cause the pilot screw to be stuck but the rest to be free?

Could I also ask, would larger jets richen up my mix or should I stick with the stock 138 and 140 jets and just adjust the pilot screws out? If they both richen the mix then what would be the difference in each?

 

The screws used in syncing the cards are not the same as the pilot screws. There are 3 screws used in syncing the carbs, for carbs, 1, 2 and 4. Those three carbs are all synced to #3.

The pilot screws are near the bowls. They could get stuck from being all gunk'd up. I wouldn't recommend trying to change jets to fix an issue. You change jets to make the bike perform differently. If you don't fix the issue at hand, changing the jets will just add another wrinkly in your existing issue.

 

This is not an f3 (probly a fireblade) but the screws are there, under the carbs. They have a special head that requires a special bit to be turned.



You need a tool like this, a screwdriver with a 90 degree angle gear or you need to remove and flip the carbs over to turn the screws.

 

That is the exact one I have Matti. I've also used a hacksaw to cut a straight slot groove in the screws. It's an easy thing to do, but you do risk messing up things if it's not done properly. I also followed suggestions and tried a used .22 shell casing. I didn't have the same good luck with it that others have.