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Accelerator pump mods or update parts

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I have a 05 450x I've been playing suspension for a bit and have it handling ok next is the dreaded flame out and low speed operation. Thanks to the info on here I'm finding jetting pretty easy with great starting points in many threads. One thing I'm wondering is the fuel pump! do I grind the rivet, oring mod,leak jet and adjust timing etc etc or fit the modified 08 onward pump cover,rod and diaphragm?? If I fit the modded parts does the leak jet still need a change ?? I've searched and there is not much information on the updated parts. Also are they a Honda part if so anyone have the number? I've only found info on CRF'sonly regarding this.

 

Cheers 

Marty 

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I used a 50 leak jet. Wire tied AP leakage (o ring fails quickly) and shaved off rivet to 3mm to extend AP stroke. Done. No need for additional parts for me.

A lot of guys are installing a merge racing spring or a later model spring. This will work as well.

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The above works. 

It can bind for many, but it works.

You should not need to change the apump diaphragm, but inspect it anyway. 

If the 'rivet' has any height, get the newer ('07) version.

Stretch the apump diaphragm spring to be 1" longer.

Change to a  R&D racing linkage spring; stiffer than merge racing, stiffer than a 100 orings, and cannot bind like tieing might cause.

Go to a 40/45/50 leak jet (if you have the back fire screen removed and a non-stock air filter, you go to a smaller number)

Now lift up the subframe, and with a dead motor and the help of a friend and a good flashlight, whack the throttle and watch the squirt.

It should just barely miss the slide, even with a slow whack. Just barely.

It should also squirt all the way in to the head in a steady stream for 1 second or so

 

You will need to go back and re-adjust your fuel screw for the fastest idle drop....

Edited by Krannie
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Thanks for the reply Krannie yet again :) This type of info just helps time wise less experimentation. I knew it was wrong based on what my Yamahas were like, the std squirt is very poor indeed.  Onto the spring asap. Have you had anything to do with suspension valving on these?? I've not pulled it part yet but both ends have excessive face shims at the very least !!! Do you know what the std mid valve float is on them or the std stacks either end ?? Any stacks for a 180lbs B grader would be a great guide :) :) 

 

Cheers 

Marty

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I do not know these forks.

I pay someone else to know.

I no longer have room in my work space to disassemble anything of any size or 'oily-ness'.

My business has taken over my three car garage, and the bikes get about 1/4 of the remaining space.

It's a good problem to have....

 

I HIGHLY recommend:

 

AS RACING for all your CRF motor and suspension needs.

 

Edit:  I just noticed you are in OZ.    Oh well....

Edited by Krannie

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 Change to a  R&D racing linkage spring; stiffer than merge racing

 

I always preferred the R&D spring to the Merge spring, but it appears that R&D no longer offers the spring for sale separately. I can't find it anywhere. I emailed R&D and never got a response. Do you know of a source for the R&D spring Krannie?

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I always preferred the R&D spring to the Merge spring, but it appears that R&D no longer offers the spring for sale separately. I can't find it anywhere. I emailed R&D and never got a response. Do you know of a source for the R&D spring Krannie?

I confess I have never bought it separately, although they used to sell it that way.

R&D (Dean) is a really attentive guy, if you call him.

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James I'm in Perth Western Australia :) I found the spring only from Ballards.cc They had to look "out the back" for it as its not listed anymore so its on the way now :) :) Just about to pull the suspension for a revalve, fix the carb etc etc I'm looking forward to my next ride even though its heading towards summer and DUST.

 

MM 

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