Jump to content

04 WR450 AP Bog/Hesitation

By Borgschulze,
in WR400F/426F/450F

 Share

Recommended Posts

Proficient

Borgschulze

Posted
Posted

Hi, I've got a 2004 WR450.

 

It sat unused for 2 years in the previous owners garage.

 

Cleaned everything up, adjusted the valves, idles great, pulls hard, doesn't stutter at constant throttle, can do nearly 160kmh with the SuMo wheels, except when you try to loft the wheel from under 4500 RPM, it bogs/hesitates for probably 1/8th of a second, then pulls hard.

 

Currently it has
 

168 Main

48 Pilot
1 Turn out Mixture Screw

ACV Blocked

70 PAJ

OBDUQ #4 Clip

Blocked Leak Jet (A hair under 1 second of squirt)

AP Diaphragm Stamped 3.1?

AP Linkage Wired, no binding.

Stock Pipe with baffles removed (Loud, sounds like crap too, gotta replace that heavy beast)

Airbox cutouts removed and snorkel removed.

1250 ft Elevation 20-30 degrees Celsius.

 

I've adjusted the AP Squirt to full advanced, and it's not hitting the slide... the bog is a lot less than when I first started tuning this bike a few weeks ago.

 

Now... I don't claim to know it all... and probably made some mistakes along the way...

 

But I feel like the AP squirt with the screw turned out completely should be hitting the slide? Maybe someone swapped in the wrong diaphragm?

 

The bike used to bog for about a half second before I took the time to try adjusting the AP squirt, so it's getting better, but I can't even adjust it to hit the slide, so something is wrong?

 

Am I expecting too much to be able to loft the wheel under 4500 rpm?

 

I can roll on the throttle fairly quick and it's fine, but the second I try to wack it open around 4500 or less, it falls on its face, then pulls hard, it just comes on softer than a quick roll on.

 

Link to comment
Share on other sites
Grand Master

FORMA MOTO

Posted
Posted

Do you have the short, medium or long apump diagragm rivet?

You want short for fully uncorked (which includes the YZ Header and pipe upgrade)

 

Wiring the linkage is not the best way:

-changet he apump linkage spring to a stiffer version  http://tokyomods.com...arburetion.html

-replace the pump diagragm with a 2008 version/upgrade kit  http://www.crfsonly....roducts_id/3932  which includes the proper push rod

 

45 pilot is what you want

 

2006 YZ needle or NCVS needle

  • Like 1
Link to comment
Share on other sites
Proficient

Borgschulze

Posted
  • Author
Posted (edited)

I think mine is the medium rivet.

 

What makes that new style AP cover better? I notice they move they check valve from the float bowl, down into the AP cover.

 

Is that Tokyo Mods spring really required? Can I just order the Merge spring from CRF's Only?

 

I'm in Canada, so I'm going to pay out the ass for shipping.

 

$35 shipping from CRFs Only...

Edited by Borgschulze
Link to comment
Share on other sites
  • 3 weeks later...
Proficient

Borgschulze

Posted
  • Author
Posted

Installed all the parts... still can't adjust the squirt to hit the slide. The push rod is the same length as the one that was already in the bike, and yes I punched out the check valve in the float bowl.

But it doesn't seem to be bogging anymore, so it must have helped.

 

Changed to 45 Pilot, 165 Main, and the NCVS on 3rd clip.

ACV is disabled, and TPS unplugged, and mixture screw all the way in, the bike still runs... isn't particularly hot out, only 23 Celsius.

 

Seemed to run best around 1.75 turns out.

Link to comment
Share on other sites
Proficient

Borgschulze

Posted
  • Author
Posted

I'm just worried that buying all these parts won't fix it, till I buy a new carb.

 

My slide plate has some wear marks on it, but the seal seems fine.

 

I'm supposed to be taking a week off work next week, and was hoping to have the bike sorted out...

 

This carb doesn't look super abused, it's quite clean inside.

 

Guess I should order a slide plate and seal then?

 

Only other thing that could be replaced after that is the float needle and seat, and needle jet.

The needle jet looks great though...

 

Wish someone could just lend me a carb that works for next week.

Link to comment
Share on other sites
Grand Master

FORMA MOTO

Posted
Posted

I'm just worried that buying all these parts won't fix it, till I buy a new carb.

 

My slide plate has some wear marks on it, but the seal seems fine.

 

I'm supposed to be taking a week off work next week, and was hoping to have the bike sorted out...

 

This carb doesn't look super abused, it's quite clean inside.

 

Guess I should order a slide plate and seal then?

 

Only other thing that could be replaced after that is the float needle and seat, and needle jet.

The needle jet looks great though...

 

Wish someone could just lend me a carb that works for next week.

 

You don't need a slide plate, just the seal

You don't need to worry about the needle and seat, if gas is not coming out of the overflow

You need to focus on the fuel screw and oring, hot start plunger sealing 100%, ACV system working, Pilot jet passage not partially clogged (fishing line and spray cleaner), and if the bike has 100+ hours, replace the needle jet (emulsion tube). 

 

When you adjust the fuel screw, there is a procedure:

 

Motor must be hot. Not 5 min hot but 20 min hot. 

Fuel screw set to 1 turn out.

Start the motor, and lower the idle as low as it will go.

Now raise the idle WITH THE FUEL SCREW.

If the idle does not go high enough, raise it now with the IDLE SCREW

If it goes too high, lower it with the IDLE SCREW.

 

NOW blip the throttle and listen to the idle drop speed.

You can fine tune the fuel screw for a faster idle drop, if you are patient, and it only takes 1/8 turns 

Link to comment
Share on other sites
Community Regular

Cooksend

Posted
Posted

Well the hanging idle is back, and I can't figure it out...

 

Kind of wish I just bought a fuel injected bike now... might have been worth the extra mo

My 03 WR450F was just rejected, Throttle limiter eliminated and smog stuff removed.  Bike ripped hard for over 10,000 miles before I had my first struggles.  First valve adjust needed at 7500 and did the top end and head at around 12,000.  Found out in the end that my real issue was a wire related to the headlight!  I still think that most days that bike would out perform my current 2015 Husky FE501.  Sure hope installing the Euro Map in my Husky changes that.

Link to comment
Share on other sites
Proficient

Borgschulze

Posted
  • Author
Posted

I've got the ACV disabled, the bike ran great for an almost 7 hour ride on Saturday... started having hanging idle issues near the end of the day, and Sunday I just about wanted to chuck it off a cliff.

 

Today was a lot cooler, had a stumble around 6-7k RPM, went back up to the 168 Main, no more stumble.

 

So KRANNIE, you really think just that slide plate seal with solve this horribly annoying issue? It looks fine visually... Or should I get a new ACV diaphragm to go with it?

 

Sometimes the idle is hanging as high as 4k RPM, and blipping the throttle won't always fix it.

 

And I'm not just letting go of the throttle, I force it closed, to make sure the throttle cable is not the issue.

Link to comment
Share on other sites
Grand Master

FORMA MOTO

Posted
Posted

You have a massive air leak

It should be easy to find.

 

 

If you disabled the ACV, why would you get a new diaphragm?

Did you change your Pilot air jet from 70 to 100 after disabling the ACV ?

 

If you slide plate seal is compromised, that is giving you an air leak past the slide.

 

I don't know everything about your carb, so I can't say.

 

If you did EVERYTHING that has been mentioned, and not just pick and choose, it should be fine.

 

You  can't leave anything out.

Link to comment
Share on other sites
Proficient

Borgschulze

Posted
  • Author
Posted (edited)

Will have to get 100 PAJ too then... didn't realise that had to be changed, but makes sense, and is probably why my fuel screw only barely changes from full closed.

 

I sprayed the entire carb down with the bike running, no air leaks from outside.

 

Guess I'll see if the local shop will get me the slide plate seal and a 100 PAJ.

 

If it's not fixed after this, you're trading me your Beta. I miss my Italian beauty Husky 610, except that she was a bit on the fat side.

Edited by Borgschulze
Link to comment
Share on other sites
Grand Master

FORMA MOTO

Posted
Posted

Will have to get 100 PAJ too then... didn't realise that had to be changed, but makes sense, and is probably why my fuel screw only barely changes from full closed.

 

I sprayed the entire carb down with the bike running, no air leaks from outside.

 

Guess I'll see if the local shop will get me the slide plate seal and a 100 PAJ.

 

The ACV is essentially a 'over richener' to compensate for the stock lean pilot.

It's only active when the throttle is closed, to eliminate the decel popping.

You do not have to eliminate it, but when it is active, it is sometimes hard to dial in the fuel screw, and it can be 'laggy' in it's operation.

 

https://www.thumpertalk.com/topic/436852-03-wr250-acv-removal/

Link to comment
Share on other sites
Proficient

Borgschulze

Posted
  • Author
Posted (edited)

Slide plate seal, and needle jet ordered... PAJ on backorder..

 

Anyone know the Suzuki or Kawasaki part number for a 100 PAJ?

The shop I'm getting the parts from doesn't try very hard to help.

 

EDIT: Found part numbers.... apparently nobody has 100 PAJ... Zzzz

 

EDIT EDIT: KTM dealer that's much much further away had one in stock!

Edited by Borgschulze
Link to comment
Share on other sites
Grand Master

FORMA MOTO

Posted
Posted

Slide plate seal, and needle jet ordered... PAJ on backorder..

 

Anyone know the Suzuki or Kawasaki part number for a 100 PAJ?

The shop I'm getting the parts from doesn't try very hard to help.

 

EDIT: Found part numbers.... apparently nobody has 100 PAJ... Zzzz

 

EDIT EDIT: KTM dealer that's much much further away had one in stock!

 

JetsRus .com

Sudco .com

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

ThumperTalk

Register a new account Sign In Now
 Share
Go to topic listing
×
×
  • Create New...
Terms of Use
Copyright
Privacy Policy