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The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> Valve clearances
Post Info TOPIC: Valve clearances
ghardison


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Valve clearances
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Hey guys hope all is well and happy new year!  So my TTR is running leaner than an Olympic marathoner.  White spark plug and no carbon build up. New spark plug.  The header is glowing red yadda yardda. This is a 2005 TTR 250 US/CA model. I am once again cleaning the carb and checking jet sizes.  I will send that info a little later as I just dropped the jets in the ultra sonic and couldn't read them just yet.  There was gunk in the emulsifier  tube so that may do the trick. Finally the jet needle is at the standard setting. I have red through all the red exhaust pipe /rich/lean threads and thanks for all the info. Now, my question. I checked my valve clearances at TDC. Intake ranges are small 0.09 to 0.10 and 0.09 to 0.11.  Exhaust are each 0.19 to 0.20. The second number in each range is the maximum sized feeler I could insert. Do you recommend thinner shims all around?  Leave it as is?   Thanks in advance. 



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ghardison


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To add to my story the main jet is a 137 and the idle jet is a 50. I see y'all recommend 145 and 52. Basically I am checking everything that could contribute to my lean condition.
I am now guilty of having two issues in one thread.

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mossproof


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I would leave the valve clearances - they are at the tight end of the range, but if they are within spec, they are within spec!
I think 137/50 was stock for some bikes, but if modifications have been done (airbox, end can etc) that would require bigger jets. Blocked carbs are so common, especially with the ethanol content making things worse. A thorough clean of all the jets (copper wire reaming) and pathways in the carb body (carb cleaner and airline) should sort it. Don't forget the pilot jet and the filter behind the brass inlet valve.
Good luck!

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ghardison


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Thanks - I will do that - any tricks to get the brass fuel needle body out to get to the filter?



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TTRfan


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Hi Greg

In my experience there isn't an easy way to remove them as they are normally stuck in there really tight cry

I use the best fitting grips or pliers that I can get on it and gently move it back and forth until it submits and pops out. Despite being very careful, I invariably end up with jaw marks on them.

Maybe go at it a different way? Using plenty of carb cleaner, blow back through the filter using the best source of compressed air you can find. This should dislodge any crud that has accumulated on the filter. To make sure its clean, just connect up and see what the petrol flow is like.  Just an idea......

I guess you have seen my guide here?

Good luck wink

Brian



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mossproof


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Could try soak overnight in penetrating fluid or dunk in boiling water, but as Brian says, just wiggle it!
You don't want to damage it unless you have a new one to hand.

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ghardison


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Fortunately I do have a new one and needle. However, I wrapped it thoroughly with tape and grabbed it with pliers. No marks. All cleaned up. Back together and running the best it has since it got dropped on my doorstep. Been a fun project. See pic for and update. 

Thanks for all your generosity. Without it I would have been lost. 



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mossproof


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Great news. Thanks for the update.

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