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07 YZF 250 Rough holding Throttle Steady

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My 07 YZF 250 has about 21 hours on it. when riding, holding it at a steady throttle (doesn't matter if its from 1/4 to WOT) its definately not running smooth, sound roughs. Its not back-firing etc just not sounding nice. Also trying to start it if its stalled while hot is an absolute mission, but not all the time! any advice?

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How long has it been doing this? Did it start doing it all of the sudden, or progressive? Have you done anything to the bike before it started doing it? Any mods? When you say it's rough, does it sound rough out the exhaust or can you feel it? What I would do is pull the carb and give it a good cleaning and replace the pilot jet then check for vacuum leaks around the intake also use some fresh gas too. If that solve it then look into ignition such as your plug and make sure the plug boot is on all the way.

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since i brought it, its been fully serviced. guys at shop said its top notch inside and out which makes me think it is to do with carb/air leak. pulled carb to bits when i got it gave it a thoughrough clean. No mods except silicone rad hoses. sounds rough out of exhaust and feels it but harldy feel anything unless i'm trying to feel it (if you know what i mean) brand new spark plug, new gas

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Hi, Ive got the same issue. My 07 WR250 not running right on a constant throttle.

Doesn't matter what throttle opening, but when cruising along the road it feels like the bike is starting to run out of petrol (gas).

The bike hesitates but doesn't actualyl slow down.

When hitting the dirt and giving it the beans it feels just fine.

The dealer had a look when I took for a valve check. They changed the plug as it did look bad and say they drained some water out of the carb. Whilst it starts much easier after being left for a couple of weeks it still has the constant throttle problem.

Any pointers guys?

Edit: Get the occasional backfire through the exhaust as well.

Edited by Andy.M

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Hi, Ive got the same issue. My 07 WR250 not running right on a constant throttle.

Doesn't matter what throttle opening, but when cruising along the road it feels like the bike is starting to run out of petrol (gas).

The bike hesitates but doesn't actualyl slow down.

When hitting the dirt and giving it the beans it feels just fine.

The dealer had a look when I took for a valve check. They changed the plug as it did look bad and say they drained some water out of the carb. Whilst it starts much easier after being left for a couple of weeks it still has the constant throttle problem.

Any pointers guys?

Edit: Get the occasional backfire through the exhaust as well.

Try disconnecting the TPS and see if it clears up. If it does then troubleshoot that system. Experiment with clip position on the needle. Popping on decel is normal to an extent.

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Thanks, I realised that, I'm not as stupid as I look :thumbsup:

I'll give it a try and let you know :thumbsup:

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OK disconnected the TPS and it runs ok.

Should I troubleshoot (where do I start?) or would it be ok to simply leave it disconnected?

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It won't hurt the bike to leave it disconnected you just lose a tiny bit of performance up top. When disconnected the CDI falls back on to a pre-programmed timing curve in its memory. To troubleshoot you need a multi-meter and the manual. The manual will tell you exactly what ohm values at what throttle positions you are supposed to have. If the TPS is good and needs a tweak then you can adjust it a little. If it needs replaced then replacing it can be a headache for some people.

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Thanks Swede youve been a great help.

When I get time I'll check it out as I have a manual and a meter :thumbsup:

Until then I'll enjoy it as it is!

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