No change after shimming needles with two washers

[jasonz1c]

So today I shimmed the needles on my 2008 250R using two washers on each needle. Here are the specs of the washers:

INSIDE DIAMETER = 3mm
OUTSIDE DIAMETER = 7mm
THICKNESS = 0.5mm

I decided to shim the needles for better launches at red lights. Took the bike for a one hour ride and I noticed absolutely no difference. With the bike at a standstill and in first gear, it bogs for around two seconds when give it a lot of throttle (i never dump the clutch when launching). The only way to stop the bogging from a standstill is to give it a little bit of throttle at first..

My bike has a Yoshimura carbon slip-on and it still has the snorkel installed.

Should I try adding another washer to each needle or should I remove the snorkel?

[quarterliter]

Try a larger main jet

[choneofakind]

No. Put it back to stock. If you felt nothing. You're out of luck. Go on with your life and continue riding.

If you can't feel it, jetting will do nothing different for you.

[TnNinjaGirl]

Originally Posted by choneofakind

No. Put it back to stock. If you felt nothing. You're out of luck. Go on with your life and continue riding.

If you can't feel it, jetting will do nothing different for you.

Wuhhh???

Have you tried 1 washer instead of 2. Jetting will make a difference if you get it right.

[csmith12]

Lol, chone must have just woke up.

[TnNinjaGirl]

Originally Posted by csmith12

Lol, chone must have just woke up.

I always tend to take his word as truth but I was a little hesitant on that one.

[DaBlue1]

Shimming the needles mainly affects the 1/4-3/4 throttle range. There maybe a very tiny bit of help at low idle, but by no means are you getting some neck breaking, wheelie popping boost from shimming. Adding 2 washers seems to do the trick for many bike, but each bike is different. Some have had to use 3 washers to get the desired result.

I would first start by removing the snorkel with two washers. The bit of extra airflow will help along the with increase in fuel you are now allowing with the needle height adjustment. (probably the cause for the rich bogging when you crank on the throttle)

If you want better overall drivibilty, these few improvements are easy to do, don't cost a lot and will make the bike respond and ride a little better. Keep in mind that a bike that is properly tuned is going to get the best results.

[choneofakind]

Lol, yeah just woke up and the grouchy pants are on.

If they did nothing, take a washer off. If you're expecting small adjustments to make your bike launch like a superbike, sorry. If you want a little smoother, then you're on the right track. Take one washer off and give it a go.



Definitely do not put in a larger main with only a slipon.

[jasonz1c]

Originally Posted by choneofakind

If you're expecting small adjustments to make your bike launch like a superbike, sorry.

Originally Posted by DaBlue1

but by no means are you getting some neck breaking, wheelie popping boost from shimming.

Well I guess I'll have to work on my launches then if I can't fix the bogging.. on the brighter side, the washers should help with cold winter starts

I'll try using just one washer on each needle next but should I also try using three washers?

Thanks for the help by the way!

[TnNinjaGirl]

Originally Posted by jasonz1c

Well I guess I'll have to work on my launches then if I can't fix the bogging.. on the brighter side, the washers should help with cold winter starts

I'll try using just one washer on each needle next but should I also try using three washers?

Thanks for the help by the way!

Try one, try 3, try taking off your snorkel. It's an art more than a science. Jetting is even more fun

[cbinker]

Do the pod filter, then test it.

[csmith12]

Hey Jason,

When I did my needle shim, I felt similar to you. Problem was me, my expectations were a bit on the high side. I think that is what chone is trying to say, shimming isn't gunna make the 250 something it's not. It wasn't until I went with a fully exhaust system w/ jetting that I felt the significantly harder pull, specifically at launch and mid range throttle.

My process was this, trial and error;
Add 1 shim, then ride - Why did I even do that, I feel nadda. Is my arse numb?
Add 2 shims, then ride - meh
Add 3 shims, then ride - Nope
Back to 2 shims, no snorkle, then ride - meh, but I see a sparkle of hope
Back to 3 shims, no snorkle, then ride - kinda yes, kinda no
Full exhaust, jet kit, then ride - cool, I can feel some added powah now
Full exhaust, jet kit, adjust clip, hi flow filter, then ride - WOOT!

[jkv45]

Have you adjusted your idle mixture screws?

If not, you're probably lean down low. Colder temps make it lean also (that may not be an issue with you right now though), as does gas with ethanol. Use the lowest octane that doesn't detonate (usually what's recommended in the manual), though cold weather (and leaner mixtures) will detonate sooner, so pay attention if you hear a "rattling" sound under heavy load. You make the most power with the lowest level of octane that just barely keeps it from detonating.

It takes time for the slides to lift (on a CV carb) when you whack-open the throttle, so you will never get a super sharp snap down low - it will build gradually.

There's just not a lot of torque available down low - no matter how good it's tuned.

[DaBlue1]

Originally Posted by jasonz1c

Well I guess I'll have to work on my launches then if I can't fix the bogging.. on the brighter side, the washers should help with cold winter starts

I'll try using just one washer on each needle next but should I also try using three washers?

Thanks for the help by the way!

Snatching out the snorkel is easier than removing the washers. Test the bike and see how it performs with 2 washers and no snorkel first. If still no love, make sure the air filter is good. If it is the original from 2008, you need to replace it anyway (Kawi recommends replacement @ 2 years). Also make sure your idle speed is properly set. Like mentioned before shimming works for some bikes, jetting may work better.