grass-digger

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Oct 21, 2001
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2002 yz250f wont rev...

hey guys i picked up a old yz250F that has been sitting around for a few years and wasent running.. the owner said it was running before he put it away and he just couldnt get it to run again... anyways... the compression is good, new fuel, carb was cleaned, air filter is clean new plug, and it only starts if you put the hot start on.. and it will sit there and idle for 30sec or so then shut itself down, restart same thing.. if you twist the throtle the slitest bit the bike shuts down, if you take the hot start off it shuts down. its a weird problem that kinda has me confused, so im asking for some help to try to figure out how to fix this thing..

thanks a bunch oh and its a 2002
 
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Ol'89r

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Jan 27, 2000
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grass-digger said:
hey guys i picked up a old yz250F that has been sitting around for a few years new fuel, carb was cleaned,

Clean the carb again. Make sure the pilot jet and starter jet is clean and you can actually see daylight through the jets. While the jets and the air screw are out, blow air through the pilot air passageways and make sure they are all clean. These passageways are all connected and if you blow air into one of them it should come out of all the others. If it doesn't, the passageways themselves are clogged. Also, make sure the accelerator pump is clean and working properly.
 

grass-digger

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Oct 21, 2001
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well one of my co workers had said he had cleaned the carb but this morning i found out he only took the bowl off and cleaned it rapidly, upon further inspection i noticed the acelerator pump not working, passages were cloged, so basicly now everything is perfectly clean and should work properly. My second question is that the float bowl comes off then you can seporate the carb from the upper float bowl type thing, my question is can you get the orings and seals that are inbetween that?, i cant seem to find them anywheres
 

Ol'89r

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Jan 27, 2000
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SFO said:
you talking about the ap seals?

I too am a little confused here. :coocoo:

The gaskets for the ap cover and for the main float bowl should be available at your local dealer. If you don't have a local dealer, try the MX South link on the left side of the page. They have a great online parts fisch and excellent prices.
 
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grass-digger

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Oct 21, 2001
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well as ashamed as i am to say this i work at a yamaha dealer.... and nobody there can find the gaskets and orings that i need they are not present in the breakdown of the carb on the computer
 

Ol'89r

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Jan 27, 2000
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grass-digger said:
well as ashamed as i am to say this i work at a yamaha dealer.... and nobody there can find the gaskets and orings that i need they are not present in the breakdown of the carb on the computer

Well, I really don't know what to say about that. :whoa: Maybe try another Yamaha dealer? :coocoo:

Check the MX South link. Click on OEM parts and then your brand /model/year. There should be two o-rings on the ap diaphram cover and one gasket on the float bowl.

If that doesn't work try www.sudco.com
 

grass-digger

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Oct 21, 2001
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whatever you see on mx-south and bike bandit, are the same parts breakdowns i have a work. but i now realise that i probobly shouldnt have taken the carb completely appart.... the carb is made up of 3 pieces that you can only see from real pictures, there is the carb body(where the slide is) then there is a part where all the jets screw into and finally there is the float bowl and ap
 

Ol'89r

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Jan 27, 2000
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Float bowl gasket. Part # 1202-896-6000
ap o-ring. # W9351-19058
ap o-ring. # W9353-36000

If you did not get a service manual with your bike, order one.
 

grass-digger

Member
Oct 21, 2001
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i can get those gaskets thats not the ones i was looking for, i know its hard to explain and everything without seeing it in person, i basicly had to disasemble the carb further then what the service manual wants you 2, but the problem was the passages for the ap were cloged and i needed to clean the junk that was inn there, i put a little bit of silicone type solution to make the old gaskets that i could not get to make them sticky again and everything seems to work great bike runs awsome, so whatever i did it worked. sorry for the confusion with the gaskets guys and if i could have shown you pictures im sure it would have helped my explaining alot better... thanks for all the help..

Jamie
 


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