yz 426f bog

[DavidBeebe]

I've seen a couple of posts where this is mentioned and I think I am experiencing this on mine. The bottom end of the throttle doesn't roll up very smoothly, leaving a dead power spot. By the time you get the motor to respond, there is too much power. Kind of spazzy. As I need to remove and clean the carbuerator (see previous post "fuel dripping from overflow") and probably replace some float bowl components, Is there something else I should do while I've got it apart? Also on heavy throttle application I can hear a whistling. Obviously sucking air somewhere. Any common spots where this is a problem?

[Florida 393]

The float needle sounds to be worn or pitted. Maybe just some crud in it holding it open a bit. Pull the carburetor and clean each jet individually then set the float level per the Faded thread in the Knowledge base forums. The FCR carbs are really sensitive to dust and grit in the jetting circuits.

The whistling noise may well be an air leak. The intake boots, front and rear of the carburetor and suspect and prone to cracking from age and drying out. Also there is a nitrile o-ring between the intake bell and the carburetor body that can crack or break or get sucked out of the grooves it sits in. If you have an air leak you will get an extreme lean condition though. This I have had t deal with and it was the nitrile o-ring at the intake bell.

For the bog I'd let G-Argyle put in his wisdom on the mod he perfected on the accelerator pump circuits or do the BK/GB accelerator pump timing modification.

Bill

[The Baron]

The early bikes that have no leak jet are harder to dial in. The best way to handle it is to buy a new style float bowl that has a leak jet from [Only registered and activated users can see links. ] . This will help you fine tune the squirt.