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hanging idle-- ughh

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ok.. so I've read the other posts. had a bad idle problem.. took it in and they adjusted valves, and cleaned out the carb - apparently i had shoved a new fuel air screw in (after the old one fell out) w/o realizing the old spring and o-ring were still in there.

I guess it still hung for a bit. so the mechanic unplugged the tps and the problem went away..

great but is this a band aid to a larger problem?

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Huh? :banghead::applause:🤣🤣

If you are wondering if having 2 sets of springs & o-rings did any damage I would think not.

If you are asking about a hanging idle usually it's due to being too lean.

How does the bike run now?

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Bear in mind, I'm no expert here (my obligatory disclaimer), but the TPS should have nothing to do with how a properly jetted bike idles. I have never disconnected the TPS on my 03' WR250f and it idles perfectly. (For the record, I have disabled the air cut valve and changed to a #100 pilot air jet as per yzf spec). But as Bkinzey indicated, a hanging idle problem is usually indicative of a lean condition. Try turning your fuel screw out a quarter turn at a time and see if this alieviates the problem. If you get to 2-1/2 turns out and the problem persists, then try increasing your pilot jet to the next size. Start with the fuel screw set at about 3/4 of a turn out from fully seated, and begin the process over again.

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The TPS is used to tell the CDI unit where the throttle is so that it can map the timing based on a combination of RPM and throttle position for more accuracy. When you disconnect it, the system can no longer function as designed, and substitutes a full throttle value in place of actual information from the TPS, reverting to an RPM only, two dimensional ignition map.

It is possible for either the TPS or the CDI to be faulty and cause this behavior, although the failure of any electronic component in a Yamaha is rare. If everything else is right, test the TPS per the manual, but try not to move or remove it unless absolutely necessary, as getting it in the right place is tricky.

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the bike has the stock jets in it. I guess they thought that having extra spring/o-ring may cause a lean condition??? I've tried the 1/4 turn thing and that didn't change anything.

:banghead:

how would i test the tps.. I don't have a manual, I know I need one though.

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When you change the fuel screw position, you should get changes in idle. The motor should idle roughly if you get it either too lean or too rich. If your motor doesn't change the way it runs in response to fuel screw adjustments, then you have a problem.

I wouldn't rule out damage caused by inserting two o-rings and washers, especially if the fuel screw was cranked in pretty hard. It doesn't take much to mess the carb up as it is very sensitive to small adjustments. Just be sure that you have the fuel screw parts installed correctly (spring/washer/o-ring, installed on the fuel screw in that order), and that the o-ring is undamaged. Get a magnifying glass and make sure there are no scratches or tears on the o-ring. Also make sure you haven't damaged the end of the fuel screw. Try another and see if it acts differently. The only way I can think of to rule out carb damage is to swap a friends carb into your bike and see if it behaves better.

Depending on your altitude the stock pilot jet (40) may be too lean. I had to go up to a 42 on mine, but I haven't disabled the ACV, like you have on your bike.

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beggers can't be choosers but could I get a link to the 2001 manual??

why can't you guys work on my bike... rrrr

If you were close I could get that thing running like a top, but I doubt you want to make the 2000 mile drive.

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