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02 CR125R starts dumping fuel, possible cause?

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 Hi everyone, I have a curious problem with my sons bike an 02 CR125R. It's been running and riding perfect all summer long but last weekend here in Oregon the temps plummeted and the rain started so we eagerly loaded up the bikes and headed for the woods. He rode his bike up and down a small trail just to get the bike warmed up and when he got back I noticed that gas was pouring out of the float bowl vent. Now, On his carb there is no screw like there is on mine as in to drain the fuel so I'm assuming it's controlled by a check valve or something? Anyways we loaded up and went home. Once home we rode the bike up and down the street several times and nothing leaked. WTF???

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probable that it was the float stuck or some dirt in there holding it open.

 

take it apart and clean her up.

 Yea that was my thought also. I neglected to mention that this is only the 3rd weekend since the carb was rebuilt. I pulled the float bowl and it all looked perfect. Also if the float stuck wouldn't it flood the engine and not just come out of the bowl drain?

Edited by kawisrok

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Its your float needle and float neadle seat needs replaced, that is if you have already checked that assy for trash and that your float is definitely set where it is supposed to...

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Its your float needle and float neadle seat needs replaced, that is if you have already checked that assy for trash and that your float is definitely set where it is supposed to...

My son had the exact same bike here in Oregon before he moved up to CR250. We had the same experience you have. Fuel dumping for no apparent reason. Cleaned the carburator , straightened out the float bowl, I think it was high, but ultimately had to replace the $16 float needle. It has a special rubber type tip.

On an unrelated note, have you had any trouble with fouling plugs? Our bike went through plugs like crazy. Always carried a spare and a wrench in the boot.

Dean

Edited by evhfan2003

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Well the entire carb kit is a month old and the fact it only done it once confuses me. We went riding yesterday and it was perfect. I think just a piece of dirt or something caused it. We had trouble with it fouling plugs and spewing black goo out the pipe when we first got it. I then put a new case seal in and it's been perfect ever since. I'd say he's ridden 15+ hours on the same plug now.

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My son had the exact same bike here in Oregon before he moved up to CR250. We had the same experience you have. Fuel dumping for no apparent reason. Cleaned the carburator , straightened out the float bowl, I think it was high, but ultimately had to replace the $16 float needle. It has a special rubber type tip.

On an unrelated note, have you had any trouble with fouling plugs? Our bike went through plugs like crazy. Always carried a spare and a wrench in the boot.

Dean

only one day when I was desperate and ran generic 2 stroke oil for outboards. Ran fine but smokey. Then next outing it never would start with that same plug again. Your running way rich or main crank oil seal leak when tranny fluid gets mixed w fuel mixture...

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If you have allready rebuilt the carb, then the float level is too high. Bend the tab slightly so the needle valve closes when the float is a bit lower.

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If you have allready rebuilt the carb, then the float level is too high. Bend the tab slightly so the needle valve closes when the float is a bit lower.

yeah, if the float isn't haging exactly where the maual tells you, it can make you run too rich. Read the manual three times, then make adjustments with the float tab, prolly a little out of "whack",,,,

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Nope. Float is exactly where the manual says .30" . Also I'll say it again, it only did it once. A misadjusted float would always do it. I'm pretty sure it was just a piece of dirt that hung up the float needle. He rode all day Sunday without a problem.

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Nope. Float is exactly where the manual says .30" . Also I'll say it again, it only did it once. A misadjusted float would always do it. I'm pretty sure it was just a piece of dirt that hung up the float needle. He rode all day Sunday without a problem.

I know, I was responding to evhfan2003...

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Float height, or stuck float needle as previously mentioned.

In regards to fouling plugs mix your oil properly. Most fools have no idea the proper ratio not do they realize their trail riding is not even close to high temps experienced in racing.

This they mix per the manual but trail ride, while rarely flogging the engine. This fouled plugs.

Belray MC-1 and H1-R at 50:1 for years in my CR125, CR500 and CR250 with hours and hours of hill climbing and trail il riding.

Never an issue.

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Float height, or stuck float needle as previously mentioned.

In regards to fouling plugs mix your oil properly. Most fools have no idea the proper ratio not do they realize their trail riding is not even close to high temps experienced in racing.

This they mix per the manual but trail ride, while rarely flogging the engine. This fouled plugs.

Belray MC-1 and H1-R at 50:1 for years in my CR125, CR500 and CR250 with hours and hours of hill climbing and trail il riding.

Never an issue.

 

The real issue is that "most fools" don't know how to jet properly.  I, being the fool that I am, mix at 32:1.  I ride trails, rarely flog the engine and mysteriously, I have never fouled a plug.  Pick whatever ratio you want, but the real key is jetting for that ratio properly.  

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The real issue is that "most fools" don't know how to jet properly. I, being the fool that I am, mix at 32:1. I ride trails, rarely flog the engine and mysteriously, I have never fouled a plug. Pick whatever ratio you want, but the real key is jetting for that ratio properly.

True enough as well. Over rich mix cannot be ignored.

All oils are not equal for the same ratios. If you think they are do a viscosity check.

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