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choke question

9K views 7 replies 7 participants last post by  AnnaAB 
#1 ·
Just picked up an 250 06' a week ago and had a question about the choke. Should it be pushed all the way forward when riding, pushed forward I believe the choke is off. I have to have the choke on to start it of course but when I let it sit there and warm up and push the choke forward it stalls out. Any advice would be nice. Thanks
 
#3 ·
I'm not so familiar with the quirks of the '08 and up models but the '07 and back units and very slow to warm up.. VEEEERRRRRRYYYYY SSSSSLLLLLLOOOOWWWW...!

Any ways, with the choke open the tachometer should read about 6000 rpm's and when the choke closed it should idle around 1000-2000 rpm range...

Does your bike idle at all..?

Is the fuel fresh or has the bike been sitting for a while..?

If the fuel is suspect then drain it out and put in some fresh...

These bikes are pretty sensitive to the condition/age of the fuel and the resultant symptoms are poor idle or difficult to maintain a consistent idle with the choke closed... It will run with the choke open but after the warm up period has been reached(temp gage has moved into the normal operating range) and the choke is gradually closed the engine will stall out...

Another thing you can try is the idle adjustment knob which is located on the left/clutch lever side of the bike in the engine bay right under the carburetor bowl. Rotating this knob will increase or decrease the idle speed... You can't really hurt anything by turning this but it may offer you a little assistance with improving your idle... Your 250 should be able to idle at about 1000 rpm but I've found that a little bit more idle rpm is a bit easier to live with no more 2000 rpm though...

http://farm4.static.flickr.com/3580/3375840764_cfeb152306.jpg
 
#4 ·
on my 09, i have to pull the choke to engage it, and push to release it. Just like an old car or truck. Normally I will start it will full choke, and let it run until the idle picks up dramatically, then half choke it. I continue the half choke while I smoke a cigarette, then after the smoke, the bike is ready to ride. Aside from fresh fuel, you may also try a fuel additive. I have had real good luck (in old cars and trucks) with seafoam. It is a petroleum distillate and it does a real good job of cleaning out small passages in the carburetor.
 
#5 ·
I messed around with the idle adjuster and got it to idle around 2000 rpm's without the choke on. Later on I turned it down a little bit more cause when it was warmed up it was closer to 3000 rpm's. I have come to find to use the choke whenever I first start it up which helps to deal with it wanting to stall out and once it warms up I remove the choke slowly. Once it warms up the bike runs like a champ! Had an amazing ride in north central PA yesterday, awesome weather. Freak and kenny thanks for the input.
 
#7 ·
When idle or choke issues arise, look for vacuum leaks. The slightest leak will make idle impossible. The CV choke is far different, it varies the slider position by putting vacuum on the bottom of the diaphragm which inhibits natural slider movement. This keeps velocity higher which makes for a richer mixture. When a CV carb is normally operating, the velocity through the slider orifice is constant so at low RPM and WOT, the slider is barely open.

To look for vacuum leaks, slowy spray carb cleaner over the vacuum lines at idle. If the RPM changes, you have found the leak. A pinhole in say the petcock diaphragm WILL cause a big change. There is a vent hole in the petcock on the back side.

I was running my F6F without tank using a one quart pony tank and had what I thought was a plug in the petcock vacuum line. The leak was a fine hole in the plug (off my MityVac tool set) about the diameter of a stick pin. Until that was plugged, it wouldn't idle except full choke. Plugged properly, it ran fine.

Just an FYI, it is easy to pull the front wheel off the ground with no gas tank ;)
 
#8 ·
This looks like the thread I need to get a little more information. I've just purchased a 2007 250 from a friend who was the original owner. The only modification to the bike is a homemade air filter (I've ordered a Uni).
I was warned that the bike is an attention hound for starting and requires a good 5-8 minutes to earn up before moving, she's also a little anemic in the lower gears.
My problem is that she won't idle and she's very unresponsive in giving it has and coming down from idle.

Do I need to replace the jets? If so, what would you recommend?

Are thereby other tricks to make this bike act less like an arthritic old woman?
Thanks for you time and response.
 
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