i bought an 03 ds650 about 3 weeks ago. The problem i think i am having is that i only go riding on sundays, so the quad sits for the whole week. when i go to start it on sunday i put the choke fully on and start it up. It starts right up, so i let it warm up on full choke for a good 2-3 minutes or so. then i push the choke it to the first click. then when i put the choke fully off it will stall. If i put the choke back on it will start fine. its only after i take it for a quick ride that it will idle without the choke on. And on the ride to warm it up i start riding witht he choke pulled out to the first setting then as im riding i shut the choke off fully. when i do this and let off the gas and then give it gas it kinda bogs. After all this the quad starts right up and ride fine all day long.

is this normal? it is still winter here. The temp at night can still be as low as about 20.

 

I would say in that cold of temps you would have to let her warm up for longer than a few mins to be able to get her to idle without using your choke. Here in Southern Cal we don't get relly COLD temps. But I no longer even have a choke on my carbs. Kinda sucks at times. But when it's cold here. mid 50's I can start mine without choke and just hold the throttle for about 3 mins or so then it will idle on it's own.

 

Mine does the same thing. When I first start it I have to baby it for the first 5 minutes. I usually ride in 2nd at a 2000 RPM to warm it up for a couple of minutes. Easier than trying to keep it running sitting still.

 

You could try turning the idle mixture screw, out (richer), about 1/4 to 1/2 turn. Its probably just a little too lean for these temps, and as summer and warmer temps come back, turn it back in.

 

ya i think i might turn the screw a little.
there is also another problem that only happened 2 times so far. one last sunday and one today. at idl if i gave it a little gas it backfired a tiny bit. like a little pop. only happened once and didnt do it at all after.


jeff

 

Yep. Im sure its lean now, either you have a intake leak, exhaust leak or the mixture screw needs adjustment. Seeing how its fairly new, i would doubt the first two causes. Heres a link to jetting and symtoms, jetting and symtoms

 

should i bring it all the way to the dealer? its under warrenty till april or is this something i can just do in the driveway? how would i know when the mixture screw is set correctly?


jeff

 

Yes you can do it in the drive way easily. I think if i remember correctly that if you have to turn it out more than 3 1/2 turns you need to go up one size on the pilot jet.
Turn the air / fuel screw in until it engine starts to stuble. Now start opening it in 1/2 turn incrments, counting them as you go. Do this until it runs rough again. Now set it back in at exactly 1/2 of the turns that youy went out.

On my 400ex I had the exact same prob. Only worse. I ended up setting the slide needle to the richest position and walla...perfect [img]i/expressions/face-icon-small-smile.gif[/img] You may try richening the neddle one postion or so.

 

this might sound like a stupid question, but where is the mixture screw located?????


jeff

 

no its not a stupid question, if you dont know where to look you wont find them. Underneath the carb, on the engine side of the carb.Heres a link to a picturecircled in green its circled in green.
There may or may not be a black cover over them.
Its probably something you want to learn how to do. Its not a set and forget kind of thing. As weather, temp and humidity change...the setting will vary a bit. As youre now finding out.