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Hesitation or slip.

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Good day everyone.

So I am having a new symptom with my drz. I am trying to determine if it is air/fuel or drive train.  2 to 3rd gear area opening the throttle there seems to be either a hesitation or a slip to acceleration. It has been running fine so far all year.  And I have not changed anything. Could it be the recent hot weather messing the air fuel up. 36 to 40 C. I am running a mikuni tm40, if my accelerator pump is shooting to early because of the heat,  would I have a symptom like this? I replaced the clutch discs about 4k ago and have had no issues to date. 15w40 motul oil and it's about 500 km old. And suggestions where to start?

 

Thanks

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Just a quick edit. Carb jetting is 25 pj, 155mj, pumper set approx 2 mm from lobe, fuel screw is between 1 1/2 to 2 turn's. BB kit, Stage 2 cams, full fmf pipe, 3x3 mod (had to go slightly larger then 3x3). 350 ft above sea level. Airbox door off runs to lean. Covered partially way to rich. So my theory right now is either to much fuel from pumper, or maybe not enough. It's a real PITA to mess with the carb, you have about 1mm cleared to get the thing in and out. So any insight would help so I only have to do this once hopfully.

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Even with all of the information provided, I'm not sure there is enough info to answer the basic question, is it a hesitation or a slip. Does this only happen in second or third gear, but never any other time? One sure way to rule out a slip is to get the bike on a surface with excellent traction, engage a high gear (4th or 5th) and go to WOT. If engine rpms increase, but the bike doesn't accelerate, you've got a slip of some type.

If you have a hesitation, have you done the simple things such as clean or replace the air filter, the spark plug, and check that all of the carb boots are properly attached? Before I start messing with jetting that has worked well in the past I always look for something that has changed.

Is there a particular throttle position where the hesitation occurs? This will help to understand if it's a pilot, needle or main circuit that is giving you problems.

Edited by Gary in NJ
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Good day everyone.

So I am having a new symptom with my drz. I am trying to determine if it is air/fuel or drive train.  2 to 3rd gear area opening the throttle there seems to be either a hesitation or a slip to acceleration. It has been running fine so far all year.  And I have not changed anything. Could it be the recent hot weather messing the air fuel up. 36 to 40 C. I am running a mikuni tm40, if my accelerator pump is shooting to early because of the heat,  would I have a symptom like this? I replaced the clutch discs about 4k ago and have had no issues to date. 15w40 motul oil and it's about 500 km old. And suggestions where to start?

 

Thanks

Yes that hesiation symptom can be from too much fuel getting shot in, especially since it's just come about since the hot weather, though pumper's usually hesitate from lack of fuel. Gary's got some good advice, but unfortunately your just going to have to spend some time trying things, sorry no easy way around it. Sounds like you have a good feel for diagnosing a rich or lean condition so good luck, and let us know what you find.

I'd probably start leaning that squirt, but i don't know the carb so i can't help you there.

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Thanks for taking the time to reply.

The boots look good, air filter was cleaned when I did the last oil change and she gets a new plug every season. 

Throttle position is about 1/4 opening to about 1/2 or slightly more. I will look closely on my way to work today, as well as test the higher gears as well. I usually don't open it up in 4th or 5th because I am allready around 100 kmh in 3rd gear. 16/38 sprockets.  

Suprisingly today will be a good test,  we're down to 15'C what a relief! I'll post more later on.

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Thanks for taking the time to reply.
The boots look good, air filter was cleaned when I did the last oil change and she gets a new plug every season. 
Throttle position is about 1/4 opening to about 1/2 or slightly more. I will look closely on my way to work today, as well as test the higher gears as well. I usually don't open it up in 4th or 5th because I am allready around 100 kmh in 3rd gear. 16/38 sprockets.  
Suprisingly today will be a good test,  we're down to 15'C what a relief! I'll post more later on.

1/4 to 1/2 throttle.
Slow roll on , or quick openning?

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It appears it was temp related. I could not duplicate it this morning. It is amazing how much heat can mess with your carb setup. I hope that is the answer and not something to do with my clutch at warmer temp's.  I will shorten the accelerator pump next time it's that warm and test it out. 

Bucket list

It's under quick acceleration.  Merging onto the hiway. I tried it on some back roads later that day and the same thing occurred. I'm am going to go for a ride now that it is 25 'c and see if it happens again, but at 15'C acceleration was smooth and crisp. It almost wanted to power wheely in 2nd and 3rd this morning. Which was suprising with my sprocket ratio. 

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