I'm curious about this as well. Can anyone tell us what the pro's and con's would be compared to running the standard 7mm insert? Better run times? Better mileage? Tamer power? Smaller tuning window?

The net effect of running smaller carb inserts is that each 0.5mm smaller equals about 10-15 sec. of additional run time. The smaller the reducer the more limited maximum airflow is, hence reducing top end however the air velocity passing through the venture increases resulting in a more aggressive bottom end. So in essence you gain a little run time, reduce top end slightly and get a slightly more aggressive bottom and mid range.

Great info..

Thank you for the information, as well as the quick response. Time to go do some testing :)

Where can we order venturis for the Werks?
Can't find them on amain.....

Can I also ask you Ron, What parts are NOT interchangeable between standard B5 and standard B6?
I can get a hold of a cheap B6 for spares to my worn B5. Can I use the crank?

Any non-Picco or non-Reds venturi should fit (If I remember correctly REDS and Picco venturi's have a larger outer-diameter than standard venturi's do).

The only thing different in the B5 and B6 are the sleeves (which are also interchangable). Everything else is the same - so that B6 would be great for spares.

We have the 6mm Werks restrictors in stock, so they are available - A Main must be out of stock perhaps.
Most of the Taiwanese restrictors are the same dimensions (GO, Alpha, Argus etc).

OS 6mm & 6.5mm also fit

Not sure why you can't find the reducers, they are just listed under engine parts, try the following link:

http://www.amain.com/Radio-Control-R...ng-21-B6/c1679

As others mentioned you can use all of the parts from the B6 with the exception of the P/S which is different.

How many head shims are in this motor?

well... I can't find the damn answer anywhere in the net.. :flaming:
is it 2 aluminum and 4 copper? :confused:

Memory tells me it's .9mm
2 x .3mm alloy, 1 x .2mm copper, and 1 x .1mm copper.

Recent B2's have a new generation head button with different shimming.
If your motor is more than 4 - 5 months old, go with .9mm

I'm sure Ron will pop up and correct me if I'm wrong on that one.

Thank you grizz1!
my caliper is at a friends house but, my older B5 came with 6 all together.. 2 alum and 4 copper.. I just replaced the P/S/CR in this engine and just wanted to make sure about this before I seal the engine..
I have a new B2 also and I see what you are saying about the shims..

I think sometimes the factories run out of .2mm shims and have to use all .1's :-)
Seen that with other engines.
The upgrade head button is sexy eh.
As always, Werks are ever improving their products quietly in the background. :-)

10-4.. and Thanks!