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Basicly stock 2004 CRF450 won't start when temp gets low.

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My 04 won't start when air temps get cool. I have to replace the plug to get it going. Then when it gets real cold (winter temps) it won't start at all. The only engine mod I have done is a 17 ounce hevier fly wheel. (I like to ride in the woods)I have no idea what's up.

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Mine will start but does take more kicks. Jetting/air screw must be the cure.

What do you guy's recommend when the temp drops say 40 degrees?

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The crf will start first kick even when 20 degrees.

My recent trip to Colorado I had to rejet to 165main, 1.25 turns out on pilot, and 4th clip position - due to altitude. I was afraid of starting difficulties, but had no problems at all.

I cant tell you what's wrong with your machine, except that 1 or 2 kick starts are normal at low temps when everything is perfect.

]

Blackbuzzard

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The mixture needs to be richened in the pilot circuit. The air is colder and therefore more dense, it needs more fuel to balance it. Try turning your fuel screw out in 1/4 turn increments. If that doesnt provide much you might need to go up in pilot size. Inevitably you will end up going up in main jet size also. Colder air makes more power so it needs more fuel :cry:

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Is the plug wet or dry? The above suggestion to turn the throttle a few times is what I do. The accel pump acts like a primer

One more thing to try is turn up the idle speed screw. And of course don't twist the throttle when kicking.

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The key to starting the Crf 450 is to first make sure the mixure screw is 1 3/4 to 2 turns out, then turn the idle screw in a full turn or so from it's normal setting to let enough air/fuel mixture to the engine until it warms up. Twist the throttle a few times and kick all the way through. Leave the throttle alone while you kick. Try this with the choke on or off. After it warms up, reset idle to normal.

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My CRF450 has been an easy starter since I bought it, but last weekend I was riding in Oregon and in fairly cool temps and it totally refused to start. I made a trip to the local Honda shop, plopped down $13.50 (!) for a new plug and went back to try it again. It still refused to start. In desperation, I tried a proven 2 stroke technique and cracked the throttle at the same time I kicked. The bike immediately fired and settled down to it's usual ragged idle. I have always been told this is a cardinal sin, but the reality is unusual problems sometimes call for unusual solutions. What made me try it was knowing that during cold temps, my wifes 427 Corvette sometimes requires 15 or so pumps of the gas pedal to even think about starting. I've been told by "experts" that two pumps is the max ever needed, but I don't believe everything I hear and only half of what I see...

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