Spluttering in the whoops


13 replies to this topic
  • stev0

Posted August 23, 2010 - 03:38 AM

#1

My bike has started to splutter in the whoops. Just weird.

It feels like it could be fueling or ignition related.

2006 model, AIS still in place.

I think its due for a spark plug too.


Any other places to look into?

  • YamaLink

Posted August 23, 2010 - 04:44 AM

#2

So it just started? What have you done lately?

Wash the bike....water in the carb?
Made changes to jetting or needle?

Only in the whoops at a certain throttle input?

My bike has started to splutter in the whoops. Just weird.

It feels like it could be fueling or ignition related.

2006 model, AIS still in place.

I think its due for a spark plug too.


Any other places to look into?



  • stev0

Posted August 23, 2010 - 04:51 AM

#3

I was the bike all the time. I doubt there is water in the carb.

It comes and goes. At first I thought it could be dirty fuel (old jerrycan) But this is the second tank its done it on.

As soon as I get some air, the bike feels like I need to switch to reserve. As soon as I stop its fine?

Perhaps its the petcock?

  • William1

Posted August 23, 2010 - 05:01 AM

#4

Check the float height

  • Wr420

Posted August 23, 2010 - 10:26 AM

#5

I have an 07 wr450 that started doing the same thing this spring. I just kept riding it since it would only happen a few times during an enduro. I just pulled the bike Everthing looks ok no dirty jets, accelerator diaphragm was ok. One thing I did notice was the drain line off the throttle cable covers was clogged. Maybe someone with more knowledge could tell me if that is a problem. Havent put it back together since I just ordered a Quickshot 2 and a Power Now. I'll post results this weekend.

  • William1

Posted August 23, 2010 - 10:37 AM

#6

I have an 07 wr450 that started doing the same thing this spring. I just kept riding it since it would only happen a few times during an enduro. I just pulled the bike Everthing looks ok no dirty jets, accelerator diaphragm was ok. One thing I did notice was the drain line off the throttle cable covers was clogged. Maybe someone with more knowledge could tell me if that is a problem. Havent put it back together since I just ordered a Quickshot 2 and a Power Now. I'll post results this weekend.


That vent off of the throttle wheel cover being clogged will have next to no effect.

The PowerNow is not a good thing to use, It will slow your bike down,. I masks incorrect jetting.
The QS2 is pure carb bling and will do next to nothing. You would of been much wiser to of posted a question in the jetting forum carefully describing what issues you are having and what the exact jetting was in the bike. Ususally for less than $40 the problems can be made to go away.

  • Wr420

Posted August 24, 2010 - 03:45 AM

#7

I was just trying to help and respond since I was going thru the same problem. Why attack me, I read hundreds of reviews for both items and most had positive results

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • miweber929

Posted August 24, 2010 - 04:18 AM

#8

Gonna need a thicker skin to hang out here then!!!

Doubt any attack meant, certainly nothing personal. William was just trying to save you money based on the actual performance/dollar value of your purchases.

There are lots of "magic" mods for HP 4 strokes these days and the vast majority do absolutely nothing other than waste money on most bikes. It is in your best interest to do a search on anything performance-wise before spending money on it, especially a forum dedicated to your particular bike.

JMO

Mike

  • William1

Posted August 24, 2010 - 04:27 AM

#9

I was just trying to help and respond since I was going thru the same problem. Why attack me, I read hundreds of reviews for both items and most had positive results


Not trying to attack you, sorry if you felt that way. I was (hopefully) catching you before you spent the money on those items. Part of my response too, was resolving a question you had.


The powernow masks bad jetting. You bike will seem to be better but it will be slower. If that is your goal, and spending $80+ to do it is what you want, then I apologize. Thing is, for $30 worth of jets, you can resolve any jetting problem and get 100% performance. These devices are fine for someone who has no desire to jet their bike properly and has no access to help to get it done. Do a search in the jetting form, see what the experts (ignore my comments there if you like) have to say. Same goes for the QS2. A different leak jet, a spring or an oring, and a few minutes spent test riding and adjusting the AP timing is all it ever takes to rid yourself of the bog.

Think about the carb you have. It has been the state of the art bike carb for over ten years. There have been small changes over the years. These gimmicks have been on the market for years. Don't you think if there were valid solutions that Kehein would of modified the carb? Don't you think every racer in the world would be using them? BTW, the oring mod or spring is the current changes Kehein is doing. The stock spring has been getting stiffer over the years and the carbs on Hondas (the ^&%&*) already have a improved linkage that negates the need for the mod entirely-must be a deal that was made allowing only them to have it right now.

But if you are convinced you are on the right path, do this, do a timed run with your bike the way it is now. Then install these parts and do another timed run. You decide.

  • Wr420

Posted August 25, 2010 - 06:01 AM

#10

Ok fair enough. I apologize for the accusation. Now to my problem, I have an 07 wr450 that starts to die in the whoops. I bought the bike used and the guy I got it from had done the throttle stop, air box and main jet to 165 and pilot to a 48. The AIS is still on. Bike always ran great for the last three yrs. I just remembered that I swamped it at the last Jersey DS at the end of last year. Maybe I have debris in my airbox? Also I read alot on jetting on this site and will not get my bling. Thanks for the guidance

Edited by Wr420, August 25, 2010 - 06:22 AM.


  • William1

Posted August 25, 2010 - 06:56 AM

#11

Ah... more facts. Pull the carb and give it a good cleaning, confrm there is nothing in the airboot.

  • Wr420

Posted August 26, 2010 - 06:14 PM

#12

Ok, Igave my airboot a check and it had sandy debris in there, maybe the whoops would get it bouncing around in there and I would draw it through the carb. Just a theory. I pulled all the jets and checked out my set up. Seems I have stock jetting with the AIS still on. 162 main, 45 pilot and a 52 leak jet. The ap arm is wired to the bolt, and it has adjustable fuel screw. The bike runs well but very hot. I Have the tip completely out of the muffler. I was going to do the AIS kit since it hasnt been done. Will the jetting from the kit be right for my bike?

  • William1

Posted August 27, 2010 - 03:50 AM

#13

Check your valve clearances too.

Are you sure the wired AP does not bind?

Also, you might want to try the bike in the whoops with the wire off. A wired AP makes it more sensitive. As the bike bunces, your wrist moves somewhat, this can cause the AP to continually squirt, making a super rich mix.

  • Trailryder42

Posted August 28, 2010 - 12:39 PM

#14

A lot of bikes come from the factory with only the minimum float drop spec'ed and set. The max drop stop is not set at all and is often way too much. That allows the float to bounce between stops. On rough terrain like whoops, every time the float is forced downward it displaces fuel. That sudden fuel displacement can cause a jet of raw fuel to be shot up thru the main jet, causing a stumble.

Set your max drop only 5mm more than what the minimum drop spec is.




 
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