XT powernow

I saw a webpage regarding the powernow for an XT350 and asked for the autocad drawing, here is the result so far (tomorrow I'll testdrive it)

http://www.westerbaen.cistron.nl/xt350/powernow/powernow.html

More information here:
http://scaryfastracing.net/pn-info.html

Even with a CV carb the effect will be the same, I cannot see a reason not to use it there. Also 3/4 throttle will have effect btw.
I have emailed mikuni for a twin flachschieber carb set, but they say they do not have that and would not be possible (probably due to the small space between the two carbs while each of them is 76mm wide (TM24 and TM28) and the distance between the centers is 66.5mm) So I'm now thinking of a Y-inlet piece to combine the two and put something like a single Flachschieber for a Suzuki DR350S or similar... someday

Well on the CV carb you already have a sort of powernow plus, the flap/valve which you move. And because this has to be bonded I'm not thinking of one at the other side. Also because of the space I had to leave between the end and the slides themselfs I doubt if an extra hole will make such a difference, mine is not very wel made as it is a first. Maybe I will take them in production and let them be made with lasercutting technique from Stainless Steel. We'll know tomorrow if the bonding/glue was the right one and if there is a (significant) difference in torque

Glue/bonding is ok, and especially around 5.000rpm there is a significant difference, below maybe also but beacause of the 19/55 sprockets and the 17inches I might not feel that. Very fun bike

Zitat von jester

You wrote:
"Maybe I will take them in production and let them be made with lasercutting technique from Stainless Steel."....- let me know about it and I will order a set!

Mja, we're quite far from that point, I am making new ones, this time beter size/fit and holes in m

-edit- updated:
http://www.westerbaen.cistron.nl/xt350/powernow/powernow.html

Zitat von Benni XT350

i´m wondered
what the hell is it for a screw on the left .......... (i dont know the englisch word) i marked it on the following picture

That screw is with wich you screw the plate from the arm to the slide/schieber itself if you take it apart for changing the needleheight for instance.
And yes those two pieces of thick paper I use for distance to the slides (they are from tobacco roling papers, not too thin, not too thick) So yes they were removed before starting

Zitat von Rentnerblitz

Hi zusammen,
Benni: das sind wohl nur Kartons zur richtigen Positionierung der Bleche, so dass sie nicht am Schieber (slider) streifen.

Thats right, although the slides can have a lot of play, so you could end up pressing them up one side, with karton etc, and then when trying to use it, they still would touch each other (hope not though), also you want to place the powernow as close as possible up to the slide, otherwise you can get a downdraft wind from that space

Zitat

Baffo: ok, I understand the hole, but what are the additional cuttings good for?
To easier bend the metal??
Then: is there a chance to do an after/before comparison?
Thanky for an answer and keep on trying!

The extra cuttings were in the design in the first place, but left them out with my first try, and yes now that I have cut them out, bending the flaps was easier.
Before/after would have been best on a dynojet/dynostar, now I only have my own feeling to tell me (and you all) what it does.

Zitat von Benni XT350

wow
my carburator dont have such a screw.
i change the needleheight by changing the height of the clip on the needle in the slide... well, i think its doesnt matter greeds benni

Bizar, because the left carb is a mechanical one, the other one is a constant vacuum carb, the mechanical one has the arm attached with 2 screws to the slide, maybe u just changed the needle height of the CV?

OK, with the new/improved powernow thingies, the difference is now noticeable at ~4.000rpm, it really takes of.
Also because of the shape of the slides I think the CV carb has the most advantage because the underside is flat.
And what is 4000rpm, would that be half for the left, and 1/4 for the CV carb...
O and btw, my XT350 is a 55V from 1990, and my previous was also a 55V from 1986, and every other 350 I changed the settings from, all have this hole and screw (all 55V's)
2nd btw, I made the things out of 'blik' which would be tinned thin plate-steel