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Serious problem with my new YZ426F

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So yesterday I ended up going to pick up this guy's 2002 YZ426F off of craigslist.

I get there and I was shocked by how clean the engine was, the plastics, and the entire bike looked like it had hardly been ridden like he described... He fired up the bike and it fired right up first kick but would unfortunately die if the choke was not out all the way and the bike way not revved up..

So I figured (as he described) it would be an easy carb clean. Went to Del Amo motorsports and got a few new parts to throw on the bike while I had it apart, new pro taper handle bars, grips etc..

I get home and change the oil (which looked brand new) replaced the air filter, replaced the coolant, etc.. Finally I get to the carburetor.

I take out all the jets except the "Pilot air jet" and "Main air jet" these were not well pictured as to their location on the manual. They ended up being hidden in the main boot so I removed that and was very sad to find this picture...

yz426jet.th.jpg

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The jet on the left is the "Pilot air jet" which help regulate the bikes idling. This would not turn or budge AT ALL. I tried sawing the crevice down so I could turn it with a flat head and the brass just broke off (no way it is coming off now).. (it is actually worse now then the picture shows) Most of the metal surrounding the jet has fallen off so 75% of the jet is now exposed although it is certainly not going anywhere.

Hopefully you guys can get an idea of what im dealing with here and offer some keen advice as to a remedy..

Cheers,

Doug

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U can probably just drill them out and pick out the left over out .... Then clean the threads up with a tap.....

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If you have broke off the metal carb bell where the slow air jet is located the carb is junk.

If you really mean the pilot jet in the carb bowl, all that will happen is the bike may run poorly at idle speed on rough ground.

If you are not up to the task of removing the stuck jets, take the carb to a machine shop. At a minimum, you need to replace the damaged jets and the pilot jet (to solve your idle issue).

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Your pic looks pretty typical of dissimiliar metal corrosion.

You have a choice....if the bore of the jet is intact, clean it out and leave it as it is. Performance will not be affected.

Or...

Drill out the old jet and hopefully cause no further damage.

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Ah.. did not see the picture the first time. If you mean that tiny 'ring' about the jet, it should be OK though I cannot recall if the jet sits on top of it or inside of it.

DG is right about the corrosion, looks like 'salts' exposure. Soaking in PB Blaster and using the proper tools might salvage it.

However, I disagree with DG (a very rare occurence) about performance issues. Being it is an air jet, it is very dependant on how the airflows into it and a torn up jet face will affect the airflow.

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Well.....you know the old saying, "a picture is worth a thousand words".

So...I looked at the pic and thought, "thats not that bad".

On reading W1 post where he was in disagreement over performance, I read the rest of the post. I guess what the OP has now, is something which resembles a profile of the Rockies. (My bad)

I'll have to agree with W1, a fairly regular occurrence (:busted:), performance will change.

If you can tidy up the face of the jet, I would still leave it in there. I have removed similar jets to those in the pic and it is not that easy without adopting the correct procedure with the proper tools.

I have, in the past, left them as shown in the pic below, with no issues.

Carefull though, it's easy to scrap a carb.......:busted:

carb.jpg

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drill and easy out. i drill the brass as big as I can without getting into threads then I get the perfect sized easy out. heat the body minus rubber parts in oven to about 3560 degrees farenheit then use the easyout to remove the broken jet

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drill and easy out. i drill the brass as big as I can without getting into threads then I get the perfect sized easy out. heat the body minus rubber parts in oven to about 3560 degrees farenheit then use the easyout to remove the broken jet

Thats one hell of an oven you got there.

The carb should be pretty molten long before you reach that temperature.

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3560 F will vaporize the carb as in nothing left, not even a molten blob. :lol:

Porcelain pottery is only fired to 2400 F and that is HOT. I think the poster meant 350 degrees.

You might find a cheap used carb on ebay.

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Im having the same issue with my low hour 02 YZ426. Ive tried heat, drilled it out and tried an extractor with no luck. Im getting ready to send it to Tokyo Mods to see if they can do it and perform some of there mods. I really dont want to take a chance of damaging it at this point. Keep us posted on your progress.

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