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hesitation after shifting.

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i have been doing some searching and reading on this issue. i am still confused and looking for a starting point :thumbsup: . bike was running pretty good except for the bog issue down in low rpm's. changed out the leak jet to a #40 and used an o-ring (thick) around pump timimg screw and linkage. now the bog is gone down low, but when i get on it, on a straight, shifting into 3rd there is a hesitation for a second or so. same in 4th and 5th. i have a 05wr250f, snorkel removed, 6-1" holes in air box w/ foam vents, no-toil air filter, baffle removed from exhaust, gray wire removed, 178 mj, stock pilot (40?), #40 leak jet, needle is stock. spark plug is brand new. white bro's fuel screw 1 3/4 turns out. should i start with the ap timing screw? or could it be in need of a smaller main jet? or do i just go for the bk mod? i ordered a jd jet kit. should i wait until the kit is installed, and i am able to adjust the needle to see how it responds?

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40 leak jet with the AP mod= TOO MUCH SQUIRT,take out the o-ring or bump up your leak to atleat a 65 to make it leaner! Make it simple,take out the o-ring first,then adjust the ap timing by the manual.If it cleans it up,you can try the o-ring again,but get that 40 out of there with the AP mod.

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i left the #40 leak j in and removed the o-ring. adjusted the timing screw in and out. but the bike had the off idle bog. i put the o-ring back on, adjusted the timing screw and now the off idle bog is gone but the mid range dead spot is back. so i am going to change out the leak jet to a #50 then to a #65 if needed. i have read a lot on here that a #40 leak jet is good to get rid of the "bog", that is why i installed it. thanks for your reply.

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i left the #40 leak j in and removed the o-ring. adjusted the timing screw in and out. but the bike had the off idle bog. i put the o-ring back on, adjusted the timing screw and now the off idle bog is gone but the mid range dead spot is back. so i am going to change out the leak jet to a #50 then to a #65 if needed. i have read a lot on here that a #40 leak jet is good to get rid of the "bog", that is why i installed it. thanks for your reply.

Running the 40 leak with the ap mod will be too rich,that is right you are going up in size on the leak,which will lean it out. Did you have the bog with the o-ring out while riding or idling then snapping the throttle open? If you do not have the bog with the motor totally in running temp range while moving,leave it alone.Roll along in 2nd gear just above lugging it ,chop the throttle then open it up! Another thing is to adjust the AP screw, you have to set the slide to a certain height, in the yz manual it is .8mm. Then you turn in on the AP screw until there is play between that and the linkage. Once you have play then you back out the screw until the play just tightens up. After that you can return your slide to original position so it will idle.

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No offense to each and everyone's suggestions here. They are all good! But you've got to do the hard work yourself and not just take any internet suggestions and blindly follow them. Every bike is different and you have to take the intent of the advice and make it fit your situation.

Pull your carb off and measure and time the squirt as described in thumperfaq.com. Getting the length of the squirt to .6 to .8 seconds and timing the start correctly will solve your problems. Following a suggestion may or may not.

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ok, i took the carb off and cleaned it out. replaced the #40 with a #50 leak jet. moved the needle up to position #3. put the o-ring back on the ap timing screw and linkage, adjusted the timing screw and fuel screw. the bike is running great. no bog or hesitation at all. i am going to run it for a little while then pull the plug. i can't keep the front tire on the ground during full acceleration. i was expecting to find i needed to adjust something else after getting it off the stand, i guess not. thanks for the input.

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Everyone's suggestion,I am the only one giving replies! Sure single me out. :ride: Just kidding. :thumbsup:

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