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02 yz250 carburetor something blocking float valve/trying to find a gasket

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I got my yz250 running pretty well, and I adjusted the float/cleaned it out pretty well but it's still just pouring fuel from the overflow. It seems like there's a black chunk of something up in where the float valve seats, but I don't know how to get it out. I took the little insert thing for the jets out (3 torx screws) but it didn't really help. Does anyone know what it could be? Rubber? Someone said it's ethanol. It seems like I can't take the carb apart any further.

My other issue is about that insert that the jets screw into. It had a gasket between it and the body of the carburetor, and I can't find the gasket online, or even in any of the diagrams for the bike. I think that might be what's causing it but I'm not sure.

18471264_10212444361415305_1429422582_n.jpg

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Well that gasket is toast for sure. I'm assuming it's a piece of gasket stuck in the float hole. Did you try to blow it out with compressed air. From both the fuel inlet side and the bottom?

I once had intermittent cutting out, so i pulled the carb to clean it and found a bunch of little black particles inside. Ended up being the fuel line from my tank to carb was deteriorating. Just a thought.

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21 minutes ago, asian195 said:

Well that gasket is toast for sure. I'm assuming it's a piece of gasket stuck in the float hole. Did you try to blow it out with compressed air. From both the fuel inlet side and the bottom?

I once had intermittent cutting out, so i pulled the carb to clean it and found a bunch of little black particles inside. Ended up being the fuel line from my tank to carb was deteriorating. Just a thought.

So far I tried spraying it out with carb cleaner from the bottom. I don't think it's come out but I can't seem to find it anymore which makes me think it got stuck back in there even further. The fuel line is in pretty decent condition, it's sort of soft but it's not breaking apart or anything yet.

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2 hours ago, jwolfe said:

I got my yz250 running pretty well, and I adjusted the float/cleaned it out pretty well but it's still just pouring fuel from the overflow. It seems like there's a black chunk of something up in where the float valve seats, but I don't know how to get it out. I took the little insert thing for the jets out (3 torx screws) but it didn't really help. Does anyone know what it could be? Rubber? Someone said it's ethanol. It seems like I can't take the carb apart any further.

My other issue is about that insert that the jets screw into. It had a gasket between it and the body of the carburetor, and I can't find the gasket online, or even in any of the diagrams for the bike. I think that might be what's causing it but I'm not sure.

18471264_10212444361415305_1429422582_n.jpg

Did you polish the brass seat ?

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31 minutes ago, kxrob said:

Did you polish the brass seat ?

No. How do I remove it?

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57 minutes ago, jwolfe said:

No. How do I remove it?

You don't , get a cue tip in a drill and some polish and clean the seat up . Got video on you tube that explains it . Worked a treat on a ktm 200 carb . Video is of a mikuni 

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17 hours ago, jwolfe said:

I got my yz250 running pretty well, and I adjusted the float/cleaned it out pretty well but it's still just pouring fuel from the overflow. It seems like there's a black chunk of something up in where the float valve seats, but I don't know how to get it out. I took the little insert thing for the jets out (3 torx screws) but it didn't really help. Does anyone know what it could be? Rubber? Someone said it's ethanol. It seems like I can't take the carb apart any further.

My other issue is about that insert that the jets screw into. It had a gasket between it and the body of the carburetor, and I can't find the gasket online, or even in any of the diagrams for the bike. I think that might be what's causing it but I'm not sure.

18471264_10212444361415305_1429422582_n.jpg

Check with Ken @ KRP racing for a new seal on the metering block that you removed. He is a member here, and you will not find that gasket in any diagram as the metering block is not a end user removable service part. But Ken makes a special one and the gasket is part of it, so maybe, he has extras for a price. As for your needel and seat, blow it backwards with air compressed. and polish the seat as described.

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On 5/13/2017 at 3:42 PM, Gary YZDOC said:

Check with Ken @ KRP racing for a new seal on the metering block that you removed. He is a member here, and you will not find that gasket in any diagram as the metering block is not a end user removable service part. But Ken makes a special one and the gasket is part of it, so maybe, he has extras for a price. As for your needel and seat, blow it backwards with air compressed. and polish the seat as described.

Well I polished the seat and got it shining pretty good, blew that thing out (maybe I just can't see it anymore), and I had someone stop by with anaerobic gasket maker and we rode it for about 20 minutes and it seems to have stopped the leak. I was worried about the gasket maker blocking the little idle hole on top of that block but it's still idling so I guess it hasn't.

I have a new issue now, it was running nicely before, but now I have a weird sputter right before the powerband. It appeared immediately after we were done working. I don't think the gasket maker is the issue. It was spraying a lot of oil out the exhaust so we adjusted it to be leaner a quarter turn at a time (turn the screw inwards right, prob should have checked but he had to leave) and it seems to be running a little better. The sputter seems to have changed positions in the RPM range to be a little higher.. is it just running rich now for some reason or is something else wrong here?

Still looking for that seal in case this doesn't work. I couldn't find Ken on the site and the one on JetsRUs seems to differ slightly than the one on my bike.

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@KPRacing

if you can sell the seal/gasket he is talking about, let him know. 

10 minutes ago, jwolfe said:

Well I polished the seat and got it shining pretty good, blew that thing out (maybe I just can't see it anymore), and I had someone stop by with anaerobic gasket maker and we rode it for about 20 minutes and it seems to have stopped the leak. I was worried about the gasket maker blocking the little idle hole on top of that block but it's still idling so I guess it hasn't.

I have a new issue now, it was running nicely before, but now I have a weird sputter right before the powerband. It appeared immediately after we were done working. I don't think the gasket maker is the issue. It was spraying a lot of oil out the exhaust so we adjusted it to be leaner a quarter turn at a time (turn the screw inwards right, prob should have checked but he had to leave) and it seems to be running a little better. The sputter seems to have changed positions in the RPM range to be a little higher.. is it just running rich now for some reason or is something else wrong here?

Still looking for that seal in case this doesn't work. I couldn't find Ken on the site and the one on JetsRUs seems to differ slightly than the one on my bike.

As far as your problems go, there is no way to properly diagnose without knowing float height, jetting, needle position, AS. Stock 02 is 5.5mm-7.0mm, 178/50, 2nd clip position 1.5 out on AS 32:1. If you have a healthy top end you should be over 225psi. 

Let us know what your thinking of doing next. 

I tagged Ken, if he had them, I'm sure he will let you know. 

Edited by Gary YZDOC

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