Joined Nov 2001
17K Posts | 773+
Ely, England
I've had a batch of these rings made and put them up for sale. known at the moment as a "44mm venturi ring" I have them for sale through the web shop and on ebay.
as you can see, the ring is nearly square to give it strength in the corners.
you basically have to completely strip your carb right down and then bore it out like the process in this video;
https://www.youtube.com/watch?v=FklW_eRNoRk
clean it, bolt is back together and then you are away...in its simplest form!
of course, I'd recommend my jetting kits!
I'd recommend my short Blue Belmouth in an alloy AFA with a cone air filter.
the Blue belmouth is actually about 43.5mm internally so blends almost perfectly into the 44mm rebore.
The Blue Belmouth gives you a lot more torque.
Does the jetting kit work with the kit? well according to my Dutch buddy; Mad menno, yup! he just changed a MJ and a PJ.
But I gave him my carb with no air filter and this 100mm ex Fi stack and he said that it gave the most power of all and that he could keep woth Husqvarna 701s no problem on both torque and power.
Alas, i still need to make sure this stack can operate inside an air filter so that bit is work in progress.
several of you questioned how I got 100bhp from an engine three years ago, well this carb was part of it! a fantastic cam is the other major difference.
Jump in CSA from a 39 to a 44mm carb is 27%
Jump in CSA of the 41 to the 44mm carb is 15%
Menno reported that it gained as much at the bottom end as at the top end. I wasn't surprised at this. I had a 650 Husaberg outit with this tested also against the 630 KTMs made in Belgium by GWR and the Husaberg produced the same power, just needed careful starting that's all whereas the GWR is Fi and just "starts".
with this fitted, i suggest it makes it more important to have an Akro system and a really strong cam. with the bike this heavily modified now, I'd guess that a bespoke ignition would bring dividends too!
Taffy
