Why is my 400 so hard to start?

Usually starts first or second kick in the summer but when it cools off about 15 kicks. Kicking it thru with the comp release several times doesn't seem to help. Full choke no throttle, it runs good, after warm up starts 1st kick, just getting the @^^*! thing going. I checked the valves they were in spec

Edited by DPete

Are you running a low idle speed?

Are you saying you have to use choke to get it started? That sentence is confusing.

You SHOULD have to use choke.

When it cools off outside, the air is more dense, which leans out your current tuning. Try retuning the fuel screw. Come out with it a little(richer).

If the bike is sitting in storage a while between rides, the fuel screw passage can become occluded from the ethanol fuel turning old. Doesn't take long. Bike won't start or run worth a crap. Only thing to do is remove it and related components and clean that passage.

Edited by Trailryder42

Yes full choke on cold start. I ride it usually once or twice a week so it isn't sitting with gas in it. I'll try the fuel screw out and see what happens, thanks

Do you know your jetting? It should not be so lean that it starts ok with choke in the summer but won't start with choke when temps drop.

No idea on jetting, I bought it last summer so this is the first winter I've had it. It starts on half choke or sometimes no choke in the summer. It came from sea level and I'm only slightly above. I'll turn the idle up a little and back the fuel screw out 1/2 turn, we'll see what it does tomorrow

I suggest you start by turning the fuel screw all the way in til lightly seats, counting turns as you go, so you'll have a reference of how many turns out it was where you started from. Never go more than 3 full turns out.

Checked fuel screw, was 1&1/2 out, set to 2&1/2, gave idle screw 1/4 turn faster, fired on 2nd kick, started and ran on 3rd, thanks for the help. I have 2 other old thumpers neither one is that finicky about temp changes 

Edited by DPete

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