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Has anyone fixed there hard starting erratic idling yz250f!?

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Hello and thank you in advance for any information from experience...

I have read about 20 yz250f articles on erratic idle and hard starting yet no one has said they have fixed it. It seems to occur on the 01-05 yz250f's and i have read a ton of advice. Here is what is wrong and what i have done...

The Bike is very difficult to start. Most of the time it takes bump starting and when it runs it either is normal idle but if i dont increase the throttle super slow it will bog and stall. or if i get the throttle going it then sits at a fairly high idle where it revs and responds fine but sounds at half throttle. Also the odd time i take the spark plug out it is wet so fuel is making its way in.

Valves are well within spec ( I have tried to get them as far from tight as possible without making them loose) replaced cam chain as well

Vacuum leaks, I have been told vaccum leaks can cause this and i have double and triple checked the intake and carburetor.

The carburetor I have cleaned every inch of it and yes i put the slide on the right way. I even took apart the center section and the gasket looked fine. I then took another carb and stuck it on with no such better luck so Im pretty sure we can rule out the carby.

I ran the standard tests in the manual for checking electrical problems and all were within spec.

Spark looks good, timing is as close as one can get has anyone solved this kind of issue????

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Fuel Screw/Pilot Jet

Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method. Do it with the bike fully heated up.

Gently turn the screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly). Once warmed, slow the idle to the lowest possible speed.

*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***

Turn the screw in until the idle becomes rough or the bike stalls.

if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.

If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.

Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.

If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.

If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.

If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,800 rpm, but go by the spec in your manual.

It may well be your technique of kicking. Many guys will jump on and fan the kicker. That is the wrong way. Instead, gentle pressure until resistance is falt, then slowly increase pressure and speed. Doing it that way on a bike with a properly jetted carb is a one kick affair for me, model year bike means nothing, they all have the same carb.

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