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Flaming out problem


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Took my 2009 YZ450F out for a 2 day ride last weekend and it ran great, except it flamed out at idle several times. It did it a couple of times when I chopped the throttle in neutral after idling for a few seconds, but mostly it would just die after about 5-10 seconds of idling in gear. I thought it was lean because I had to use the cold start to fire it up even when warm, but it didn't pop excessively at all, and my jetting seems to be on par with what I should be running.

My jetting:

45 Pilot

162 main

stock needle in 3rd position

pilot screw at about 3 turns out

Boysen QS2

I'm in Texas, the elevation was about 700' and temp at about 75F or so.

My bike has a Rekluse Pro and it does drag a bit at idle. This probably is contributing to the flaming out issue so I may try a different spring.

Any thoughts on my jetting and what I can do to solve the flaming out issue is appreciated!!

Thanks

?

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Turn up the idle speed just slow enough to keep the bike from rolling forward.

Recheck the fuel screw setting too.

Flaming out is a poor choice of words. He simply means it stalls. Flaming out really means a air or fuel problem that induces a stall, hence it being a poor choice of words. You can flame out in a river with the airbox filling with water.

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Which spring/ball combo does your clutch have in it now?

All the balls (27) and the medium spring (recommended initial set up per manual). I do like the low and hard engagement.

I did try playing with the idle speed, it of course helped with the creep forward issue with the auto clutch, but it idled too low and stalled more frequently.

I was thinking the higher engagement spring and trying to play with the fuel screw a bit more. It's odd though that no matter what temo the motor was at, even at full operating temp, it started better when the cold start choke was pulled. From what I have read here a 45 shouldn't be on the lean side for my temp/altitude. Maybe I should try cleaning it.

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With mine the problem was the engagement rate. I currently use "medium/soft", also a recommended setting in the package instruction manual.

The medium engagement point is selected by using the small center spring (which they say needs to be there in any setup) and the shorter of the two outer springs. I had that setup with 27 balls (hard rate) at first, and had trouble with the clutch failing to release enough under power in a high gear, and not slipping enough to allow a second gear startout. The cure for me was to drop to 24 balls ("soft" rate). Works near perfect now. Your installed plate gap is also important.

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With mine the problem was the engagement rate. I currently use "medium/soft", also a recommended setting in the package instruction manual.

The medium engagement point is selected by using the small center spring (which they say needs to be there in any setup) and the shorter of the two outer springs. I had that setup with 27 balls (hard rate) at first, and had trouble with the clutch failing to release enough under power in a high gear, and not slipping enough to allow a second gear startout. The cure for me was to drop to 24 balls ("soft" rate). Works near perfect now. Your installed plate gap is also important.

They supplied 3 outer springs with mine. I used the middle one. The Rekluse works flawlessly except the slight creep at idle, and Rekluse will probably say that is normal. Mine slips very little, but I like that. The plate gap was less than the "no go" gauge after break in, so it should be ok. I may try the higher engagement rate spring and a 9 oz weighted flywheel and see if it helps.

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Try the 24 balls instead, or at least try that too. Mine doesn't creep at idle, really. It will start to, but then if I blip the throttle and let the clutch engage, it disengages cleanly again.

There's nothing particularly soft about the so called soft rate with 24 balls, it's just more gradual than 27 was. Give it a shot. It's not permanent.

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Try the 24 balls instead, or at least try that too. Mine doesn't creep at idle, really. It will start to, but then if I blip the throttle and let the clutch engage, it disengages cleanly again.

There's nothing particularly soft about the so called soft rate with 24 balls, it's just more gradual than 27 was. Give it a shot. It's not permanent.

OK, I'll give that a try. ?

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