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Cold weather starting

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How hard starting should the kx250f be in cold weather? We havn't had time to look at anything on it, but it wouldn't start in 20 deg F weather.

The valves were in spec (according to the shop that swapped out a case half), and its had about 10 hours of riding since.

Is there anything special you guys that do the cold weather riding are doing? Or are they just tough to start? Or is something just wrong with this thing...

Edit: I just got off the phone with the owner, and he says that in those last 10 hours of riding, the bike got harder and harder to keep running. Meaning that it would not idle... If you try to let it idle, it would kill. If you keep it rev'd up, it would be fine. I'm guessing carb needs a cleaning... Any other ideas?

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remove the sparkplug or the air filter and give it a squirt of gas from a pump bottle, replace sparkplug or air filter, full choke till she fires, works for me

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Edit: I just got off the phone with the owner, and he says that in those last 10 hours of riding, the bike got harder and harder to keep running. Meaning that it would not idle... If you try to let it idle, it would kill. If you keep it rev'd up, it would be fine. I'm guessing carb needs a cleaning... Any other ideas?

Could be possible somehow the valves came out of spec within those 10 hours very doubtful though.

Other check... I run the thick weight oil 10w-40(at least for winter temps) in my 250f and it struggles to turn over when really cold like that. simple heat gun over the engine block for a couple minutes helps a lot. The rough idle would be the thick oil and cold weather combo.. full choke it and let it warm up for a good couple minutes. Works like a charm for me

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Making sure the carb is clean is never wrong.

But you should always give the throttle two full twists before starting in cold weather.

This will make the accelerator pump squirt some extra gas into engine. It will help.

In cold weather a 5w-40 oil could be a good choice too. It is a bit thinner when cold.

A #42 or #45 pilot jet would be good too. Check what jet size you have when you clean the carb out.

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use a hair dryer to heat up the engine, my 08 wouldn't start after sitting in a cold garage for a few weeks, put the hair dryer on the engine for a few minutes, fired first kick

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