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06 CRF450R Still Bogs?

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Ok here it is:

2006 CRF450R

FMF pipe

Currently has a pretty dirty air filter :( but a clean one will go in soon (bike is parked for winter anyway)

I am pretty much stock otherwise.

Elevation is 3200 feet and I usually ride in between 50 and 100 degree weather.

 

So my bike has always had the typical low end bog.  I never really cared but occasionally on trails i would need a little brap and the bike would bog and leave me stuck on a steep uphill.  Now that I have all winter to dive into it I would like to do so.  Before I put it away, I did the AP mod found on CRFsonly.com.  I just did the easy one with the o-ring, not the full one.  This made the bog even worse.  So what is the deal?  What do I need to do to get this thing to not bog like that?  It runs fairly well otherwise but the bog sucks for trail riding and I know it can be better...

Any ideas?  I think a JD jet kit is in the future too possibly...

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Billions of posts on the subject!

 

You need to first check to see if your parts are in good order, then change the leak, adjust the linkage, and you should be fine.

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Billions of posts on the subject!

 

You need to first check to see if your parts are in good order, then change the leak, adjust the linkage, and you should be fine.

Oh i have definitely used the search button...my problem is that everyone has success with the ap mod and for some reason I did not.  I found one thread like this and it was another useless thread that ends with no answer and the OP did not mention how he fixed it

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Oh i have definitely used the search button...my problem is that everyone has success with the ap mod and for some reason I did not. I found one thread like this and it was another useless thread that ends with no answer and the OP did not mention how he fixed it

Everyone but you?.... This is a dead give away your carb is f'd up my man.. Jd jet kit. Maybe even the 18 buck rebuild kit off of eBay, borrow a compressor, watch a few crf450r carb rebuild videos on YouTube and then dial it in like Krannie explains to everybody about once a day and get back to us sir Edited by Diggla117

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In a nut shell your bike usually Boggs down when it has more fuel then it can burn, running rich. Your plug is prob straight black and maybe even wet. When it's lean it'll backfire or pop a lot and your plug will be light gray. Goodluck

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 The dreaded bog: how to fix it.

 

  • New 2007+ CRF450R accelerator pump (ap) diaphragm. This is the very short rivet diagpragm. You have to have this.
  • Stretch the ap diaphragm spring out 15mm longer
  • soak the ap cover check ball section in solvent to free up the check ball (just do it) till you can hear it moving
  • Install new Merge racing ap linkage spring (the oring does not last, and can bind)
  • 40/45/50 leak jet (no backfire screen+ twinair/ twin air / stock filter)
  • put it all together
  • lift up your subframe (dead engine) and watch the squirt
  • it should miss the slide every time, but just barely, and last 1 second (leak jet size)
  • if you need to delay the squirt, turn the linkage screw (under the throttle wheel cover) clockwise
  • if the squirt does not shoot all the way into the head, or dribbles or sprays erratically: you need to clean the brass ap nozzle in the intake bell using real carb cleaner. spray the carb cleaner up the angled passage at the back of the carb body under the float bowl cover. Make sure your throttle is held wide open when you do this, cause the cleaner can damage the slide plate seal. Spray, and wait 15 min and spray again, until the spray from the nozzle is good. This could take many sprays if it's corroded. Be patient.
  • test ap system again
  • now, adjust your fuel screw. if your fuel screw is not adjusted properly, you will get idle-bog.
  • set your fuel screw at 1 turn out. start motor. drop idle as low as it will go
  • now raise the idle with the fuel screw to max idle rpm
  • if it goes too high, drop the idle with the idle screw again, and repeat
  • must be adjusted with a steaming hot motor (throttle body must be warmed up)
  • now adjust fuel screw in 1/8 turns for quick rpm drop after blipping. 
Edited by Krannie
  • Like 4

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In a nut shell your bike usually Boggs down when it has more fuel then it can burn, running rich. Your plug is prob straight black and maybe even wet. When it's lean it'll backfire or pop a lot and your plug will be light gray. Goodluck

Wrong.

If it bogs rich, it will blubber and not accelerate. It will also be very slow.

FCR carbs have a lean bog, when the ap system is not in perfect shape.

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Wrong.

If it bogs rich, it will blubber and not accelerate. It will also be very slow.

FCR carbs have a lean bog, when the ap system is not in perfect shape.

Never had a ap issue but that makes sense. Bogging because the ap is starving the carb of fuel. Only thing is the mod accelerates the ap therefor giving the carb fuel faster so if it was running rich it would make the bike bog more. Either way it's worth the extra twenty minutes to make sure everything in the ap checks out while rebuilding the carb. Jd kit is def the way to do though if your a regular weekend mechanic, Goodluck!

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 The dreaded bog: how to fix it.

 

  • New 2007+ CRF450R accelerator pump (ap) diaphragm. This is the very short rivet diagpragm. You have to have this.
  • Stretch the ap diaphragm spring out 15mm longer
  • soak the ap cover check ball section in solvent to free up the check ball (just do it) till you can hear it moving
  • Install new Merge racing ap linkage spring (the oring does not last, and can bind)
  • 40/45/50 leak jet (no backfire screen+ twinair/ twin air / stock filter)
  • put it all together
  • lift up your subframe (dead engine) and watch the squirt
  • it should miss the slide every time, but just barely, and last 1 second (leak jet size)
  • if you need to delay the squirt, turn the linkage screw (under the throttle wheel cover) clockwise
  • if the squirt does not shoot all the way into the head, or dribbles or sprays erratically: you need to clean the brass ap nozzle in the intake bell using real carb cleaner. spray the carb cleaner up the angled passage at the back of the carb body under the float bowl cover. Make sure your throttle is held wide open when you do this, cause the cleaner can damage the slide plate seal. Spray, and wait 15 min and spray again, until the spray from the nozzle is good. This could take many sprays if it's corroded. Be patient.
  • test ap system again
  • now, adjust your fuel screw. if your fuel screw is not adjusted properly, you will get idle-bog.
  • set your fuel screw at 1 turn out. start motor. drop idle as low as it will go
  • now raise the idle with the fuel screw to max idle rpm
  • if it goes too high, drop the idle with the idle screw again, and repeat
  • must be adjusted with a steaming hot motor (throttle body must be warmed up)
  • now adjust fuel screw in 1/8 turns for quick rpm drop after blipping. 

 

Thank you sir!

This is what I needed!

I can absolutely tell you that the ap squirt does not shoot like it should.  It is like a dribble.  So that is obviously one problem.  Waiting on the new air filter before I begin so I can eliminate that as an issue as well.  This is a great write-up, thank you! 

  • Like 2

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Thank you sir!

This is what I needed!

I can absolutely tell you that the ap squirt does not shoot like it should.  It is like a dribble.  So that is obviously one problem.  Waiting on the new air filter before I begin so I can eliminate that as an issue as well.  This is a great write-up, thank you! 

Your nozzle is probably corroded, or your pump system is corroded.

Use REAL carb cleaner, sparingly, with the throttle held wide open, and spray it  quickly in the the angled passage just below the nozzle, that is visible only when the float bowl cover is removed.

Do it once, wait 15 min, do it again, repeat, until it is clear.

You can also use ultra (ULTRA!) fine wire from a piano or gituar string. Do not use welding tip cleaners or pipe cleaners and they are too soft and can break off.

Edited by Krannie

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Thank you sir!

This is what I needed!

I can absolutely tell you that the ap squirt does not shoot like it should.  It is like a dribble.  So that is obviously one problem.  Waiting on the new air filter before I begin so I can eliminate that as an issue as well.  This is a great write-up, thank you! 

Question KRANNIE you said if it goes too high drop the idle with the idle screw again,and repeat . What do you mean by repeat ? thanks

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Your nozzle is probably corroded, or your pump system is corroded.

Use REAL carb cleaner, sparingly, with the throttle held wide open, and spray it  quickly in the the angled passage just below the nozzle, that is visible only when the float bowl cover is removed.

Do it once, wait 15 min, do it again, repeat, until it is clear.

You can also use ultra (ULTRA!) fine wire from a piano or gituar string. Do not use welding tip cleaners or pipe cleaners and they are too soft and can break off.

 

why not just strip the damn thing?

i like to take them all the way down

 

i do it about once a week on my brothers because its on methanol....

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Your nozzle is probably corroded, or your pump system is corroded.

Use REAL carb cleaner, sparingly, with the throttle held wide open, and spray it quickly in the the angled passage just below the nozzle, that is visible only when the float bowl cover is removed.

Do it once, wait 15 min, do it again, repeat, until it is clear.

You can also use ultra (ULTRA!) fine wire from a piano or gituar string. Do not use welding tip cleaners or pipe cleaners and they are too soft and can break off.

Would wd40 be fine to use

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