that is getting on the low side but it runs my atc 250r has had 150 psi for about 4 years and runs great. Sounds like you need to adjust your idle up a bit.

 

If it runs good and strong, keep running it. As suggested by Mony25; adjust your idle...this can be done at the carb and the Thumb throttle...

Carlos

 

i did i open all the choke and nothing the throttle cable is new and is complete open on my thum throtlle in the handle bar the engine run good
what the minimun of compression before i need to change the rings and piston???

 

looks how this look it have some wear it this normal ???

 

<IMG id=vbattach_5029 class=previewthumb alt="" src="http://www.trx250r.net/forum/attachment.php?attachmentid=5029&stc=1" attachmentid="5029">looks how this look it have some wear  it this normal ???

 

if it still slides up and down in the carb freely without catching or being sticky its okay.

your idle is adjusted by the screw on the side of carb not choke

 

I don't think the wear on the slide is the issue as to why you cannot keep an idle, specially if it idles with the throttle cracked open. However; slides do wear out, and the one in the picture is worn out...this would make adjusting, tuning & jetting difficult as the slide will not seal up properly in the carb slide channels.

If your carb adjustment at the carb and your screw ajustment is all the way to it's limit and still will not hold an idle; try loosening the cable completely at the Thumb throttle and pull on the cable a bit...does it idle? If it does, you need a different cable as yours is too long.

Carlos

 

thank you carlos i did all with the carb no luck that means the if the slider is wear out i need a new carb or they sell the slider
the cable i buy it from motion and this was the one they recomend it on the other pic i could streach thecable and i have a gap before the carb open and this is the number for the cable

 

thank you carlos i did all with the carb no luck that means the if the slider is wear out i need a new carb or they sell the slider
the cable i buy it from motion and this was the one they recomend it on the other pic i could streach thecable and i have a gap before the carb open and this is the number for the cable View attachment 5073 View attachment 5074

That extra length in the cable does not allow the slide to position at the right height relative to the adjustment screw/nut. If the threaded portion threads into the Thumb Throttle correctly, then it cannot be the Twist Throttle cable since they have different ends. Does your cable have an added adjustment joint between the carb and thumb throttle? If it does, take the slack up at this point by unscrewing the joints...

Carlos

 

Check the pilot jet. If its plugged up with scale or varnished then it won't idle. Make sure the carb is clean and the float level is set properly. The idle is adjusted by the choke plunger if it is the stock PJ carb. Screw it in (clockwise) all the way, then back it out until it idles as desired. The cable has nothing to do with the way it idles (unless the cable is too tight and is lifting the slide). However, from the pics it looks to me like you may have a cable for a twist throttle (judging by how loose it looks). If the cable is hooked up properly and you have that much slack in it, you definitely have the wrong cable. Hope this helps.

 

whats the part number for a thumb throttle cable mine is the one onthe picture that the one that motion give for my year of mi bike