Hesitation problem - your thoughts please


19 replies to this topic
  • Bibleman

Posted August 25, 2007 - 10:26 AM

#1

Hi guys, I have an 07 "L" with Daves mods (160 main jet) and an FMF Q2 slip on. I recently noticed that at full throttle only and only in 4th and 5th gears and only at mid rpms, I have a definite hesitation problem. I have about 1100 miles on it. I pulled the plug and I thought it looked real good - clean, a tiny on the dark side rather than on the white side. I may have gotten a bad batch of gas, but I've gone through at least two tankfuls since then, run some Seafoam and water remover. I've also drained the bowl. Any other thoughts? I wouldn't think the CDI would go out this soon nor would I think it would give these symptoms. Float at wrong level? Valves need adjusting???? If I have to I'll take the carb off and do an inspection but I'd rather not.

  • Bibleman

Posted August 25, 2007 - 12:09 PM

#2

Update, I just checked my new plug after about a 40 mile ride. Clean as a whistle and the electrode is even a bit white. Definitely NOT rich - if anything a bit lean. Somehow my fuel is getting blocked off to a degree. Is there a fuel filter in the tank? 55/160 with 2 1/2 turns out SHOULD be enough gas right? It's a very hot day here so if anything it should be running too rich I would think. Maybe something is stuck in a jet, but if there's a filter, how could something get in there? PS Anyone know how to check the float level? If I'm going in there I'm checking everything.

  • goblin127

Posted August 25, 2007 - 01:01 PM

#3

You could allso check the cond. of your air filter. Make sure its not dirty or over oiled.

  • Bibleman

Posted August 25, 2007 - 04:25 PM

#4

Thanks Goblin, but I cleaned and properly oiled it:prof:

  • Mickey XR650L

Posted August 26, 2007 - 08:43 AM

#5

Double check your Fuel Vent

  • Bibleman

Posted August 26, 2007 - 08:46 AM

#6

Hmm, there's something I didn't think of. How do you check for proper venting?

  • Mickey XR650L

Posted August 27, 2007 - 05:18 PM

#7

Mine had a vented gas cap with a tube pointed to the ground.
Re-routing tube during 4.0 gal gas tank install resulted in a pinched tube.
This created a symptom like yours.

I bought a shorter tube with 1 way vent.
No more issue and I like the look.

I am not sure how yours is vented. Try loosening gas cap after hesitation to let air in tank and go for another spin. If this corrects hesitation--locate and correct your vent problem.

  • Bibleman

Posted August 27, 2007 - 06:03 PM

#8

Thanks for your help guys, but I think I solved it with the help of Eddie Sisneros. By putting the snorkel back on the airbox I found that the symptoms got worse. By taking the snorkel AND the sidecover off the bike ran better than ever and the hesitation was all but gone. I guess the 160 main is just a bit too big. I'll either go with the 158 or vent the sidecover - I'm leaning toward the latter. Thanks for all the help!:thumbsup:

  • Whiteman

Posted August 27, 2007 - 06:08 PM

#9

With the Q2 I would think you need to go bigger on the main. I was running the 160 with the XRs Only with quite core and had the same problem. I bumped it up the the 165 and no more problem. You may notice your pipe running hot with that 160 too.

  • Bibleman

Posted August 28, 2007 - 04:07 AM

#10

Whiteman, I originally thought the same thing but my experiment surprisingly proved otherwise. BTW,are you using the Dynojet jets or the Kehin jets? The numbers are different.:prof: From what I understand the DJ 165 is about a Kehin 158 or 160.

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  • XR650L_Dave

Posted August 28, 2007 - 07:43 AM

#11

Thanks for your help guys, but I think I solved it with the help of Eddie Sisneros. By putting the snorkel back on the airbox I found that the symptoms got worse. By taking the snorkel AND the sidecover off the bike ran better than ever and the hesitation was all but gone. I guess the 160 main is just a bit too big. I'll either go with the 158 or vent the sidecover - I'm leaning toward the latter. Thanks for all the help!:thumbsup:


That's interesting- seems to back up my feeling on my 158: I'm 55/158 with the stock muffler, and I've thought it a little rich.

From when I was buying jets, I don't recall seeing a 157- anyone ever see odd sizes?

Dave

  • martinfan30

Posted August 28, 2007 - 12:16 PM

#12

think you are limited to 155,158,160,165 as far as ive found. try drilling out a 155 maybe.

  • Bibleman

Posted August 28, 2007 - 01:04 PM

#13

Personally I'd rather err on the side of a bit too rich with these hot running engines:prof:

  • Whiteman

Posted August 28, 2007 - 04:54 PM

#14

Whiteman, I originally thought the same thing but my experiment surprisingly proved otherwise. BTW,are you using the Dynojet jets or the Kehin jets? The numbers are different.:prof: From what I understand the DJ 165 is about a Kehin 158 or 160.


I used the DJ jets. That is good to know, you would think they were the same. No wonder I was getting kicked in the nuts trying to get this bike running right. Thanks for the info...

  • Frank ZX

Posted August 28, 2007 - 05:17 PM

#15

I check the float level on my kawasaki with cv carb by:attach a clear hose on the drain bowl on bottom of carb.run the hose up the side of carb.Open the drain screw on fuel bowl.You should have fuel upto where the bowl bolts to the carb body.

  • Bibleman

Posted August 28, 2007 - 06:08 PM

#16

Now that's a great tip! Thanks Frankster:thumbsup:

  • martinfan30

Posted August 28, 2007 - 08:37 PM

#17

good idea! i will try it just to see.

  • GIANTac1

Posted August 28, 2007 - 08:43 PM

#18

Did you check your stickers? It helps with speed!:thumbsup: Just joking man, hope you found your gremlin!:ride:

  • martinfan30

Posted August 28, 2007 - 08:46 PM

#19

i was hoping to get another 1-2 hp with stickers... i just need to dyno it to confirm!LOL!

  • Bibleman

Posted August 29, 2007 - 04:12 AM

#20

FYI, my stickers were the first thing I checked, I mean, that's basic:prof:
Two other side topices 1) Mr. Sisnersos said something about modern fuels not always giving an accurate reading regarding plug color and it's relationship to how rich the mixture is. That would go along with what I experienced. 2) The cooling wings definitely make a difference in engine temp - about 20 degrees.





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