Running rich?

[dug]

  Hi Guys I am in the UK with a UK bike with the foam in the lid of the airbox , this foam was missing when I got the bike which makes them run like a bitch anything over 3000 revs ,I have sorted this with a new airbox lid , now it runs fine but doesn't need hardly any choke, and some people have said it smells "fuelly" when riding behind the bike,so was wondering if previous owner had fiddled with the airscrews? any thoughts?

[Bone]

Welcome to the group.
Any thoughts you ask the previous owner might have removed the foam to allow more air into the mixture to lean it out.
I'm sure you will get replies from guys that know seems like it has been a problem.

[Red Diamond]

Pilot screws need to be adjusted and the carbs synced. While you are at it, make sure all your vacuum leaks have been taken care of as a first step.

[Dorkman]

Pull a couple of spark plugs.  If its running rich the plugs will be black and sooty.  If the fuel mixture is correct the plugs will be tan.  You mentioned that the air cleaner was foam.  Did you replace it with a K&N air filter or an original equipment filter?  These bikes don't like messing with the air cleaner.

In warm or cool weather these bikes will easily start without using the choke.  If its really cold, the choke is needed.  You might make sure the choke is all the way off by looking at the rail above the carbs moved by the cables.  It could be sticking, but then your plugs would be black and sooty.

Before messing with the fuel mixture, check the above.

[janne.smart]

Hi. Jan from Sweden.
I have had a similar root cauese but the opposit problem. It took me half a year and a lot of blod and swet,  to find out that the cell plastic, (foam) in the air box intake was missing. She got to much air , to lean mixture.
Hard to accelirate.
Now it runs perfiect.
I suspect that the carburators on your bike need to be adjusted after air filter change when air flow is changed back to  normal.

In the troubleshooting, i have disassabled the carburators, cleaned, assambled and adjusted.
Expencive, but it feels good now.
Good luck.   // Jan.