over revving at idle
 

Hi my xt600z tenere is revving up to 3000 with the throttle closed. I am in hot dry conditions (Kyrgistan 35c). Any ideas guys??:(

Air leak on manifold? Partially blocked pilot jet?

did you forget and left thechoke plunger pulled out?? it doesn't go back in after the bike has started!

Vando :innocent:

Just had the same problem, traced it to one of the screws on the secondry carb buterfly valve coming loose and allowing air to be drawn in at idle.

my screw had disapeared completely, or at least i hoped so, but the bike came to an untimley stop about 2 weeks ago about 300k after fixing the problem. Jury is still out on why, but i should know by the end of the week.

But definatly sounds like your drawing air from somewhere.

I checked everything, eventualy went back to basics, removed the carbs and blew through them, thats when i noticed it was the secondry not the primary.

Good luck

Paul

many thanks.
 

thanks guys, the problem has now stopped. A guy at the same hostel as I in Bishkek had exactly the same problem with his BMW80GS! Strange, maybe the altitude had something to do with it (800m) or maybe I'm going mad. (highly likely).

Not at all. The stoichiometric ratio for gasoline can vary according to temperature, pressure, load etc. Most modern vehicles have some form of closed loop oxygen sensor. My guess is you were running lean compounded by a botique fuel blend. For gasoline fuel, the stoichiometric air/fuel mixture is approximately 14.7 times the mass of air to fuel. Any mixture less than 14.7 to 1 is considered to be a rich mixture, any more than 14.7 to 1 is a lean mixture - given perfect (ideal) "test" fuel (gasoline consisting of solely n-heptane and iso-octane). In reality, most fuels consist of a combination of heptane, octane, a handful of other alkanes, plus additives including detergents, and possibly oxygenators such as MTBE (methyl tert-butyl ether) or ethanol/methanol. These compounds all alter the stoichiometric ratio, with most of the additives pushing the ratio downward (oxygenators bring extra oxygen to the combustion event in liquid form that is released at time of combustions; for MTBE-laden fuel, a stoichiometric ratio can be as low as 14.1:1). Vehicles using an oxygen sensor(s) or other feedback-loop to control fuel to air ratios (usually by controlling fuel volume) will usually compensate automatically for this change in the fuel's stoichiometric rate by measuring the exhaust gas composition, while vehicles without such controls (such as most motorcycles until recently , and cars predating the mid-1980s) may have difficulties running certain boutique blends of fuels (esp. winter fuels used in some areas) and may need to be rejetted (or otherwise have the fueling ratios altered) to compensate for special boutique fuel mixes. Vehicles using oxygen sensors enable the air-fuel ratio to be monitored by means of an air fuel ratio meter.




I need :helpsmilie:



:rofl:

I was just going to say something like that.

:helpsmilie: