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The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> difficult starting after rejetting carb
Post Info TOPIC: difficult starting after rejetting carb
engineer1949


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difficult starting after rejetting carb
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i have an open enduro with derestricted exhaust and opened up air box jetted to suit the better breathing, now runs really well no hesitating just pulls well right through the range BUT starting is now not good with the original jets it started allmost immediatly with the choke button out ,now it needs several twists of the throttle to squirt fuel into the inlet track but once it fires up the choke does seem to have an effect as you have to keep the choke out for a few seconds then ease it in once the engine has a bit of heat, any suggestions with the fault much appreciated .   

 

 

john



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JOHNYBOY


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tight valves

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mossproof


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Suggests to me the pilot jet might be a bit small now. Could try opening the fuel screw a turn or 2 to see if it makes any difference. (Put a dab of paint on the fuel screw to make it easier to judge how many turns you've made)

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engineer1949


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thanks for the replies sadly i dont think it is either of the suggested faults compression is exellent from cold and once started mixtures are spot on plus the pilot jet is slightly larger than the original so should be richer, must be a problem with the choke /enrichment devise but cant figure out what as all seems as it should be but clearly it isnt.


john

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TTRfan


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When the engine is warm, what happens when you pull the choke out? If it nearly stalls the engine then it's working.



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engineer1949


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all sorted found it to be that after the carb rebuild the new needle jet closed earlier than the old one so fuel level was to low so much so the tube for the enrichment was not picking up fuel reset the level now all good plus more gfrunt low down.


john

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mossproof


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Well found! We'll add that to the fund of knowledge

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