Anyone tested 39 & 41mm FCR`s on the same engine?

[greenmonster]

W/o any engine mods between switch?
Differences in character, power, rideability etc?

[Drunken Monkey]

I made the switch to 41s on my '91 900ss and the difference from stock was phenomenal.

No experience on the difference between 39s and 41s, however.

[junior varsity]

Chris Kelley prefers 41's on the 900, 39's on the 750, says the ducatitech website and his store (CA-Cycleworks).

I'd like to hear more details about it. Perhaps in Tech it'll get more visibility.

[MotoCreations]

I've run both on the same 968cc (900cc overbored) '95 900CR 2-valver engine (velocity stacks only w/BoomTubes) that is in my DesmoDevil now.  The 41's worked well out of the box (mild tweaking) but I swapped onto another Ducati that was later sold.  The 39's work ok and I get better gas mileage with them and probably about same horsepower -- but I've spent so much time rejetting/tweaking and getting them to work -- I really wish I had kept the 41's.

If I had the choice again, I'd have ordered the 41's.  I bought the above 39's from Chris / CA-Cycleworks in 1999 -- there is a lot of mileage on them since then!

My recommendation: 41's and use the K&N filter option with the stock airbox.  You should be able to bolt them on and go ride within an hour and not have to do any tweaking / shimming needles / etc.  I guarantee you would have no regrets making that choice.

[greenmonster]

OK, thx,
guess I`ll stick w my 41`s then.
Was thinking, w a mildly tuned 900, you'll get a bit better acceleration w the smaller venturi.

And sometimes I consider this:



http://www.jako-motorsport.de/ , see eigenprodukte-ansaugstutzen.