Hard to start

2002 CRF450R, stock, #42 pilot, #170 main, riden mainly at 4000ft. hard to start, and just runs slugish. Valves are all set correctly. Any help please.

main jet needs to be a 158.

hard to start when hot?cold?

what is your starting procedure?

Sorry. It's hard starting cold. Choke on, a couple of 1/4 turns of the throttle, then tdc, and kick. Isn't 158 a bit smallish for a 450? Thanks Eddie.

Size of the main jet is tied to the taper of the needle and I don't know what needle that model uses. If its an "E" taper 158 sounds right. If it had a JD 170 may be closer. That said main jet does nothing until full throttle,

starting is largly;

a) the pilot jet, idle speed is criticle. Does it idle correctly?

:confused: Compression! I see gobs of guys out there jumping on the starter, feeling the resistance of the valve springs* and saying "the compression is good" when in fact the engine is deader than a door nail.

That engine has an auto decompressor, you should not neet to find TDC before kicking it?

*on a single you do not have one valve closing everytime another is opening so you feel valve spring resistance at the K starter

Sorry. It's hard starting cold. Choke on, a couple of 1/4 turns of the throttle, then tdc, and kick. Isn't 158 a bit smallish for a 450? Thanks Eddie.

not to small.

so how many kicks would you say it takes to get it running?

Usually 5 to 6. It doesn't idle real smooth, or what I mean is the rpm fluctuates somewhat. It has lots of power, but! Exhaust pipe is usually black inside. It has the OBEKR needle, which my book says is stock, 4th position.

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