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Issue with float level?

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Hey guys, while we were riding today my brother noticed a bog on his 99 KX 125. The bike ran great, and has ran great for the first few rides this year. Today after a break he noticed every time he landed from a jump it would bog bad, then rev up fine until the next jump/landing. My guess is a float issue, but since I'm a little new to carbs I thought I'd ask.

The carb was completly disassembled and cleaned at the end of winter. Everything looked normal at that point, and as mentioned the bike ran perfectly normal until mid-ride today.

Thanks in advance for any info/advice.

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2 ways to do this;

Buy a new float/especially if you dont have a manual or cant get the measurements to set the height.

Or remove the carb, if that carb has a drain on the bowl then remove it, find a broom handle and cut a piece off to about 1 1/2 inches, drill a 1/4 to 5/16 hole in the centre of the 1 1/2 long piece then drill a 1/2 inch hole in the top of the piece about 1/4 in down from the top (this is called counterboring, so there is enough room for the main jet)

Then grind a taper on yhe outside of the piece where you drilled the 1/2 hole so that it wedges in the drain plug hole and on the other side where you have drilled the 1/4 or 5/16 hole, jam a piece of clear hose into the bottom, should be about 6 inches long, take the clear piece of hose and hold it against the side of the carb, reconnect the fuel line and turn it on, the fuel will fill the bowl and come out the clear hose then stop, see where it stops, your looking at the meniscus to see where it stops.if it stops in line of where the bowl mates to the base of the carb, you should be in the ballpark, if under or over the line substantially then you will have to bend the tang on the float up or down, up lets less fuel in, down lets more fuel in.

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2 ways to do this;

Buy a new float/especially if you dont have a manual or cant get the measurements to set the height.

Or remove the carb, if that carb has a drain on the bowl then remove it, find a broom handle and cut a piece off to about 1 1/2 inches, drill a 1/4 to 5/16 hole in the centre of the 1 1/2 long piece then drill a 1/2 inch hole in the top of the piece about 1/4 in down from the top (this is called counterboring, so there is enough room for the main jet)

Then grind a taper on yhe outside of the piece where you drilled the 1/2 hole so that it wedges in the drain plug hole and on the other side where you have drilled the 1/4 or 5/16 hole, jam a piece of clear hose into the bottom, should be about 6 inches long, take the clear piece of hose and hold it against the side of the carb, reconnect the fuel line and turn it on, the fuel will fill the bowl and come out the clear hose then stop, see where it stops, your looking at the meniscus to see where it stops.if it stops in line of where the bowl mates to the base of the carb, you should be in the ballpark, if under or over the line substantially then you will have to bend the tang on the float up or down, up lets less fuel in, down lets more fuel in.

Thanks for the info. So you feel that the float is causing the bog? This symptom/cause is a new one for me.

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It could be, but then again many things can cause running issues.

What did you use to clean the carb with?

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Just regular carb and choke cleaner from NAPA. It was preventative more than necessary, part of the winter ritual around here. I need a place to start trying to figure this out, since the jetting is good and the floats are the only variable that could have changed it seemed logical to me. Doesn't mean that's the problem though.

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Yeah I mean if the float isn't right then yeah it'll cause problems, the reason I ask what you cleaned it with is because alot of people don't realise that carb cleaner is bad for rubber and plastics components inside, because of the acetone in it I remember someone telling me.

Anyway if I were you id inspect the tip of the float needle, the cavity in which the float needle is and replace the float, you will need to set the float height correctly ofcourse and the dealership should be able to give you the specs or a good tuner can, check the seals in the carb also just to make sure you dont run into any other problems

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Yeah I mean if the float isn't right then yeah it'll cause problems, the reason I ask what you cleaned it with is because alot of people don't realise that carb cleaner is bad for rubber and plastics components inside, because of the acetone in it I remember someone telling me, I use brake cleaner or maxima suspension cleaner, rubber and plastic friendly.

Anyway if I were you id inspect the tip of the float needle, the cavity in which the float needle is and replace the float, you will need to set the float height correctly ofcourse and the dealership should be able to give you the specs or a good tuner can, check the seals in the carb also just to make sure you dont run into any other problems

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Yeah I mean if the float isn't right then yeah it'll cause problems, the reason I ask what you cleaned it with is because alot of people don't realise that carb cleaner is bad for rubber and plastics components inside, because of the acetone in it I remember someone telling me.

Anyway if I were you id inspect the tip of the float needle, the cavity in which the float needle is and replace the float, you will need to set the float height correctly ofcourse and the dealership should be able to give you the specs or a good tuner can, check the seals in the carb also just to make sure you dont run into any other problems

I will do that. Thanks for the advice...:)

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