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TTR225 Idle Surge

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I recently started working on an 2002 TTR225 that was sitting for a few years. I took the carb apart and cleaned out all the jets etc so it would idle since some of the jets were obviously clogged. Now when it idles, its not really a clean idle and surges back and forth then comes back to standard idle. Is this normal or should I make some adjustments?

Thanks

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The pilot jet passage is so tiny, there's a chance that even after cleaning there is still gunk blocking it.

The preferred way to deal with this is to replace it with a new one.

(don't forget to inspect clean other passages in the carb's body)

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Also make sure the float/fuel level is adjusted as per the manual and the inlet needle not worn.

Any fine-tuning attempts done with a wrong fuel level in the bowl is futile.

Confirm the gas cap is venting properly.

Edited by mlatour

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@mlatour Thanks for the response. I will check out a few of the things mentioned. 

Any insight on upgrading the size of the jets? I have read a lot about TTR's running too lean.

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Yes most recreational trail bikes are jetted a tad on the lean side,

I've noticed this in both of my neighbors brand new TTR125 and TTR230.

One size larger on the pilot and even main jet can certainly help making starting easier and improve cool weather performance.

Oppositely their CRF125F seems a bit too rich.

Edited by mlatour

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Check the rubber carb to engine rubber boot is not split or cracked and drawing air. If all is good there and the jets are clean it should idle, the pilot is usually the culprit if it will not idle. Check also that the throttle slide is returning fully and not getting hung up causing a high idle. Has the bike much mileage on it? If a bike a stood a while without being started the carb will need a rigorous cleaning and mileage would determine if parts are worn on the carb. Is the throttle slide showing any signs of wear on the coating?

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@johneen The bike doesn't have too much mileage on it at all. It sits more than it is ran so I took apart the carb and cleaned it along with the jets. There is a small crack in the rubber tube heading from the air filter into the carb (not the carb into the engine) but I don't think that would be the issue. Once I have it idle for a few minutes and ride around without the choke on, it will idle without cutting off but as mentioned the idle fluctuates from high to low to high again. Thanks for your help.

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@irishboys11 Thanks for the post. Your first video was pretty spot on to what i'm experiencing as well. You said the pilot jet was what did the trick? My pilot jet is super cleaned out and looks fine so I have a hard time believing jets are the only issue with my bike but i could be wrong. Did you do anything else to the carb to make it run like your second video or just get another jet?

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I'm sure the rubber boot going from my airbox to the carb, as you described, was not sitting on the carb correctly and was getting extra air into the carb, leaning it out.  I made sure the boot was fully seated along with a larger pilot jet, and that solved my issue. I also had a torn accelerator pump that I replaced.  I replaced all gaskets in the carb too. Here's the damaged accelerator pump. 

IMG_2163.JPG

Edited by irishboys11

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