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01 rm 250 wont start

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i cant start it for the life of me it has 5 hours on the top end usually runs kinda good has spark from wat i can tell oddly i noticed a wire thing partiality disconnected from the carb wat could be causing it to not run any ideas plz let me know

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If you have a hanging wire, I would work on getting that fixed first.

Pictures would help as well.

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look at the spark plug, is it fouled or even getting fuel? Is the carb getting fuel?

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Fuel, air and spark. U need all three. What king of bike? Get a manual and find out what the 'wire' is or what it goes to. You need to give us specifics so we can help you out.

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I checked with one of my dads friends (who races) and he said that wire off the carb must be plugged in. Its adjusts timing to the fuel mixture. My dad's friend had a husqvarna 450 which beat Japanese four strokes, but his RM250 was ballistic :banana:

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does it have fuel? Hold the kill switch and kick the bike a few times take the plug out and see if its wet. also try cleaning the air filter , it does slow your bike down. While your doing that clean the carburetor. Check the jets to see if there blocked. Blow through where the fuel line goes on and see if that's not blocked. Also check to see how much fuel is coming through the fuel line, make sure its flowing good not just dribbling. Lastly check for a spark, If your spark plug is healthy it will have a blue spark. But a orange spark means its dieing hope this helps

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He needs to check for spark first as that wire is a like a kill switch. Check it with the wire on and off. Then when you are getting spark, blow some starting fluid in there to see if the spark is at least strong enough to turn over the engine.

He should be able to see a picture of that wire and the entire carb on one of those internet parts sites like 'moto.......'something or other.

Manual won't help much and most likely will say, 'disconnect and replace using same manner in reverse'. Manual tell you how to take it apart, but usually don't tell you what it does.

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Ok, same problem I have a 96 rm 250 I got for building a yz426f I have rode 2-strokes all my life 19 years experience I had this rm running. But the 1and 2 gear power band would fall on it's face 3-5 Pb hits hard I pulled it in the garage it died as going in one kick started back up then died as I parked it went out to start now it won't fire I have fuel spark checked kill switch went threw the wiring all seems fine I did a compression test and it should be 170-185 i did three times and kicked it tell it Max'd out after each one I full took tester off and then reinstalled it kicked it again tell max I got 220psi everytime and it won't fire please help any ideas

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Ok, so you have spark and falling on it's face and then running fine in the PB is a fuel problem be it rich (most likely) or lean. Again, blow some starter fluid in there and see if it will turn over.

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Is the float set correct? Is the fuel shut off (the one connected to the float) inside the carb stopping the fuel?

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I have redone the whole carb and yes I set the floats to 16mm what it called for, the cylinder is getting fuel and the spark is fine I have done different kind of gas mix ratio's to see if it would smooth out the PB and not cut out but it still did I also tried to lean and richen the fuel and still would cut out is higher compression because of maybe gas in the lower end building up pressure it is a stock bike I kno a full race bike will have high compression with a shaved milled head but this on is stock I just wished this thing would start like I said it ran but cut out in first second gear on the pb then it just died and now can't get it started even with good high compression do you think a top end job wouldaybe solve this are a waste of time and money I kno the carb works cuzz it flood's out after about 10-15 kicks but the spark is a strong and very dark blue like it should be not a light faint blue. Thanx for your guys help also I kno engines have always worked on and built them but I am out of ideas

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Since you had the carb off, did you check the reeds? You have plenty of compression.

Again, that's another reason to try SF cause if it fires, you've eliminated everything but 'continuous' flow of fuel past the reeds.

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This may sound odd, but take the coil and plug wire off and test them while moving it around a little. Maybe there is a break in the wire and when you pull it off to check the plug it makes better contact and when it's in the normal running position, it isn't making contact and not getting spark.

I would also try the starting fluid as wrenchr2s said.

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Thank's for you're guy's help yes I did check the reed valves and pulled the pipe off and checked all that also seems fine and yes the compression is at 220psi seems high it should be 170-185 there is another forum I read and guy is havin similar problem and running 210 psi Ima try the starting fluid later today and let you guys know if that worked and Ima also Going to try to plug wire didn't think of either of those thank you and you think too high compression can couse this problem since I'm havin it and another person with 200+ psi when should be 170-185 remeber it's all stock no milled or shaved head there ia no reason I should get over 200 psi could maybe gas in the bottom end make it a tighter sqeez for some reason build higher compression I don't think it would it would only make it harder for pistion to go down nothing to do with compression right I pulled cap of tranny and a lil hint of gas smell not strong just a faint smell

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So I went got starting fluid and pulled the choke up and it is also a turn knob for idle and it pulled all the way out the copper plastic piece broke into two pieces so I went and order'd the new one today it will be in n two days I don't think that being out or broke or half broke would have been my problem it woulda just ran hi low idle and rich or lean the air screw worked and everything didn't know was broke but I guess if half up being broke and stuck would be like half choked and cutting my power bad in first and second gear when I get the part I'll try to start with out SF and see I will let you guys know thank you let you kno shortly. PS. Please check back in a couple days if this ain't the problem and won't start still I'll post again and let you guys either way. Thanks again.

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Since you have to take the air boot off, I think, to fix the carb, leave it off when you go to start it. This is a good diagnostic in that once it's running you can put your hand over the air intake side of the carb creating a rich condition and see if it runs worse or better.

Fuel or something has to be getting into the cylinder to cause that high PSI.

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