Needle shims vs Clip

wrote:

Why more than 3 0.1mm washer I should move the clip?! 4 washers is it possible? And why have you buy 0.3mm if you can add 3 of those 0.1 mm ? 

 

I am just saying there is about 0.5 mm of adjustment space so yes 4 washer is the maximum before moving the clip.

I am not really sure if shimming between the clip grooves  is necessarily going to solve your tuning issues but for the cost involved its worth taking a chance.

I bought the 0.30 mm washers because I think it may be easier to mess up counting the super thin 0.10 mm ones. I would rather work with the thick ones or have a combination of both.

You need to remember those thin washers are the thickness of a piece of print paper!

Where did you read the distance between clip grooves was 1 mm?

I read it on a forum  a couple days ago!!  Yes I can imagine how thin they are.. we need to be careful to not curve them!! Maybe I should buy 0.3mm as well haha !!!

Just seen this thread and a 0.5mm shim WILL put the needle half way between clip positions.
Each clip groove lifts or lowers the needle by 1mm.
When measuring you need to include both the groove and the gap between which seems to have been overlooked here and measure from the bottom of one groove to the bottom of the next..
A simple way is to fit circlips to two consecutive grooves and measure the outer distance then deduct the thickness of one circlip.
This happens to be 1.4mm minus 0.4mm for the circlip and you get the 1mm adjustment each groove provides on the needle..

Thanks Zed!! Have you an idea approximately about how much AfR we gain or lose by clip ?!

The change will vary depending on air filter, exhaust, compression, valve clearance etc so you need to “suck it and see”

In my opinion, if the only change made is the level of the needle (same air filter, same exhaust etc) the amount of air flow will not change. Just the amount of fuel (volume) changes.

I remove my Pod from ebay to fit K&n pods.. they’re supposed to flow more.. Im already lean at 4000rpm.. thats why im asking it

gd4now wrote:

In my opinion, if the only change made is the level of the needle (same air filter, same exhaust etc) the amount of air flow will not change. Just the amount of fuel (volume) changes.

AFR is measured after combustion so although lifting the needle will only increase fuel flow all the other factors mentioned will come into play, this is why you can't say how much the AFR will change for one needle slot as a general "rule of thumb

wrote:

Just seen this thread and a 0.5mm shim WILL put the needle half way between clip positions.
Each clip groove lifts or lowers the needle by 1mm.
When measuring you need to include both the groove and the gap between which seems to have been overlooked here and measure from the bottom of one groove to the bottom of the next..
A simple way is to fit circlips to two consecutive grooves and measure the outer distance then deduct the thickness of one circlip.
This happens to be 1.4mm minus 0.4mm for the circlip and you get the 1mm adjustment each groove provides on the needle..
 

Sorry, leaving the clip out of the equation was a big oversight on my part.

Still on the right track with the shim washers for adjustment between the grooves. Personally never had to resort to this, only every used washers on needles of CV type carbs where no grooves present.

Curious to find out the outcome.

Yess with my old cv I’ve added 2x0.5mm washers !!! In curious to try it next summer with my VM. Maybe K&n will flow like my old new paper pods!!? I will tell you 🙂

I agree that AFR is meassured after combustion, at least that is how we do it. The point I was attempting to express (not well) was that the air flow is not effected by the change in jet needle level.

gd4now wrote:

I agree that AFR is meassured after combustion, at least that is how we do it. The point I was attempting to express (not well) was that the air flow is not effected by the change in jet needle level.

Totally agree, I think the issue was the OP was looking for a known value each notch would change the AFR by and as I'm sure you will agree, if you sat two identical bikes next to each other the change to AFR would not be the same. Changes to compression or gear ratio's can be calculated but with things like AFR there are too many variables.