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04 CRF450 hard to start when warm

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My bike start just fine when I start it for the first time and then once I get out and ride a little bit and it is hard to and I have to kick for hours. What could be the problem jetting or valves?

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it could be either what mods u have??

my body has the same prob with his 02 he has a pipe and no jetting.

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My bike start just fine when I start it for the first time and then once I get out and ride a little bit and it is hard to and I have to kick for hours. What could be the problem jetting or valves?

Whats your plug look like?

Have you checked your valves?

Are you using your hot start when its warm?

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It has a brand new head on it valves should be to spec ( I will check them), full exhaust thats all that is done. Anyone know what I should be jetted at? Im at 2021 ft. elevation what main jet and how many turns out on my air fuel mixture screw?

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Here are the specs for your bike at 1000 to 2499 elevation, at 39-60 degrees.

Pilot - 1 1/2 turns out

Slow jet - 42

Main jet - 165

Clip position - 4th groove.

Everything is the same at higher ambient temps but the main jet goes downn to 162.

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Well I am running a 162 main so more than likely my valves need adjustment, where can I go about finding the specs for valve clearance and all that?

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This video is killer:

For specs, do a search on here or get a manuel. This forum indicated the intake valves are .006 and the exhaust is .011.

Edited by Boody38

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If your valves check out fine, your pilot circuit is probably too rich. Try closing it 1/4 or 1/2 turn.

When the pilot is too rich, you may not notice when cold starting (i.e., you normally choke it anyway). But when the bike is hot it can cause the bike to start really hard.

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