Help Please, Stalling BRP

[Stinson]

Bike is not mine it is my brothers who I ride with a lot and I am tired of him cussing the the bike. Its a 03 650R that the previous owner did all the uncorking jetting so I dont really know whats in there. My bro is not one for much trouble shooting, but his bike, has a stalling problem. If he lets of the gas and uses engine braking such has going into a turn or down a hill its like the bike loads up on fuel then as soon as he goes to get on the gas, there it make a little poof sound a stalls. Then the bike acts as if its flooded and will not restart unless the bike is held full throttle and kicked, or laid over and the gas turned off so the carb will drain. I need some type of starting point for this thing. I am assumming its a jetting/float issue, but where can I start? We live in MD and ride from sealevel up to 2000 feet maybe? What jets should I look for how bout the air screw, how many turns? The problem seems to have gotten worse, maybe cause its getting warmer, or we ride more not sure. I hope someone can help cause he pretty much hates ridding the bike, he says his knee is messed up from kicking. Thanks Stinson

[AzMtnThumper]

I'd say if the bike is fully uncorked start off with a 175 main and a 68s pilot. I think I'm using the stock needle one up from the middle (one of these other guys can chime in). Mine's pretty easy to start once it's warm (usually one kick) and 2-3 kicks cold. Read up over at the Pig Pen

[BigBoreRacing]

Definitely a jetting issue..Id start with (Like AZ said) a 175/68s But at 1k' I'd start with needle clip @ the 3rd position.

I'd also look into making sure that the bike is FULLY uncorked.

Good luck ?

[KASUYAHO]

check your float level too 16mm

[Old_Man_Time]

It is the float level. The stock setting is too high. It is set for Baja wide open throttle on relatively flat surface. Lower the float level from stock 2mm.

If you pull the stock carb off the bike and hook a fuel tank to it. Now tilt the carb as if you are climbing a hill. Do it slowly stopping for a moment. If it's set to the stock float level, it will start flowing out a overflow at the back of the carb. You will notice that the carb has very little angle to it when this happens. Almost any prolonged hill would set it off. This fuel would end up in the airbox. This can cause explosions which you feel under the seat. To prevent this from happening you must reduce the amount of fuel in the fuel bowl. Lower the float level and all is well.

[Stinson]

Thanks great information. How do I go about lowering the fuel bowl float level, do I need any parts, is there an adjustment? Stinson

[Fordskin]

I notice that the 650r is pretty temprementle at the throttle {cable} idle ajustment screw. The bike should idle not far backed off from all the way screwed in. Pilot screw [right leg side of bike}on mine is about 2-3/4 out. Mine used to stall on tight trails only because it would get hot. Chucked the thermostat and now have now probs. Mind you i live in Australia where its hot and no need for a thermostat.