Keihin Carbs to suit the Hondas

[VMX Andrew]

Would a Honda 83 CR480 carb be ok to use on a 84 Honda CR500
on the proviso i change the jets to suit the latter bike.
Checked the specs and they are the same size 38mm.
Any suggestions.
 Thanks Andrew

[80-85 husky]

Should be fine... just make sure the jets inside are the same for a 500! That will be important.

pull it to bits and check the pilot needle and main jets are the same as the 500 specs... don't ask me where they are but someone here will know

[VMX Andrew]

Ok got the carb today and pulled it too bits and ordered the new
needle and jets..
Ive noticed that the slide is a number 4.0 but i think the
original is a number 3.5.
Does anyone know if this will change a lot of the jetting ??
Didnt really wanna spend over $200 on a new slide as this one
looks near new.
Any info on this subject much appreciated.
Cheers Andrew. 

[Andrew L]

I think a 4.0 will be leaner than a 3.5

[VMX Andrew]

Bike runs ok but i have another problem.
The bike idles slightly high and i cant adjust it.
Pull the choke out and its where it should be.
Would this be the number 4 slide causing this
Thenks Andrew

[evo550]

Could well be...or a lean pilot.

[JohnnyO]

It's probably more the pilot jet too small

[VMX Andrew]

Got a standard #68 pilot jet in it.
How high should i go ??
#70 or #72

[evo550]

It's hard to tell, as jetting conditions vary depending on atmospheric conditions and engine conditions/mods.
Personally, I would take all the carb settings back to standard first and then make adjustments from there.
Have you checked the pilot circuit for partial blockages?

[JohnnyO]

A 68 pilot is plenty big enough, most CR's of that era needed a smaller pilot. Is the slide bottoming properly when you shut the throttle? Maybe a small blockage as Evo says or an air leak somewhere.

[VMX Andrew]

A 68 pilot is plenty big enough, most CR's of that era needed a smaller pilot. Is the slide bottoming properly when you shut the throttle? Maybe a small blockage as Evo says or an air leak somewhere.

Come to think of it the slide doesnt sound like all my other bikes when flicking the throttle and the slide
hits the bottom with a thud.
This one sounds like its stopping just short
Ok ill pull it apart again and soak it in Carby Cleaner.
Any other info and tips??
Thanks Andrew.

[bigk]

Be careful of the #4 slide. The number indicates the cutaway and a larger number means bigger cutaway therefore leaner. Be sure to do a couple of careful jetting runs before settling. Generally one step shouldn't be enough to cause a major drama, but best to play it safe.
K

[VMX Andrew]

Be careful of the #4 slide. The number indicates the cutaway and a larger number means bigger cutaway therefore leaner. Be sure to do a couple of careful jetting runs before settling. Generally one step shouldn't be enough to cause a major drama, but best to play it safe.
K

Thanks BigK for that info.
Might be best just to bite the bullet and get a standard slide and needle as well.

[JohnnyO]

If the slide is not bottoming then check and see why because that is probably your problem. Have you got enough cable free play? Is the idle screw turned in too far?

[VMX Andrew]

Fixed the problem much to my embarressment and i dont really wanna tell everyone what the problem was
as i have a lota friends on here but who cares.
The adjuster on the throttle was wound out to far 
She now idles but ive still gotta do a plug chop to make sure the jetting is correct.
Will do that on the weekend.
Thanks guys
Cheers Andrew