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01 Yz 125

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Hey all. Not sure if anyone has run into this problem but here goes. I have a 01 yz 125 that has always run rich. I have read many articles including the one on this forum, which is great by the way. I want to check my float level but for the 2000, and up, yamaha does not give a spec for float level only "fuel level." I am willing to buy the OEM yamaha gauge but there has to be a float level spec out there. I have searched high and low and can't find it. I have also searched everywhere for the gauge and adapter. Yamaha part # 90890-01312 &90890-01466. I cant find them anywhere on the internet. I will have to wait until wednesday to order from the yamaha shop if I can't find them online. So after all this rambling does anyone know if there is a float level spec out there for a 2001 yz125 and any links to an online store that might have these parts. I have searched all over and for two days, I am out of ideas. Thanks ahead of time.

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i have a 2003 m 125 manual that states 8.7mm + or - 1mm from float bowl mating surface to botton of float. tilt carb until float lever just touches float needle and measure with caliper. 2003 rm125 has same carb so should work.

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Mine is a Mikuni TMX 38SS, is yours the same? I know you said it is the same carb but I want to double check before making the adjustment, thanks a million!!!

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Dont actually own a rm but had same problem as you and used this on my yz125. the carbs are the same (floatwise)as far as i can tell.

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Used your specs today. Measured first and it was so far off those specs I thought, no way this is right. I tried it, figuring the bike wouldnt even run. Idled by itself for 10 minutes without stalling for the first time since I have owned it. I couldnt believe it. Get this, the plug was still black afterwards. I am going to buy the fuel level gauge to get it exact without a doubt but at least i know i am on the right track. Thanks.

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Are you sure it is black from running rich? I know this is simple but having to rich a mixture can be a cause, as well as worn rings giving you some blow by. Also have you checked the timing? Is it adjustable on that 125?

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Mixture is right, I am anal about that. Bike doesnt have that many hours on it but I guess anything is possible. Timing is adjustable will have to check that out. Thanks for the heads up.

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If fuel is not running out with bike level and bike does not bog landing or taking off a jump then just jet for the way the float is set.A high fuel level in carb will give a rich mixture and a low Will bog and give a lean mixture.

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Well not even the yamaha shop can procure the parts I need to check my float fuel level. They state that yamaha does not give float level measurements, lol. Will have to make my own gauge, or go with info I get on here. Thanks to all that have helped.

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this is from my friend that works at dealer you take carb pull float bowl off turn carb up side down lift float off needle let float back down soon as it touches needle the seam on the floats should be parallel to the body of carb.

that is how his shop was trained to adjust floats

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thanks, will see how close that method is to correct when I get the parts I ordered. i will let you know.

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Here are a couple of pictures of how I made my own fuel level gauge. I found a rubber cap at the hardware store ( I think it is used on chair or table legs, maybe even crutches or a cane) that was just slightly larger than diameter of the hole in the bottom of my float bowl.

I drilled a hole through it and stuck some tubing into it. Then I twisted/wedged the rubber cap into the float bowl so that it would seal. It worked out very well and let me know that my fuel level was several millimeters too high.

DSC01178.jpg

DSC01185.jpg

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That is really good. I am going to drill and tap a second float bowl cap. Put a grease zert that is drilled out into the threads. I will post pictures when I get the parts. If that doesnt work I will use yours. thanks.

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