Ron L wrote:

calbigbird wrote:... I have a set of 41mm FCR's on my Desmodue 944 cc Ducati and am amazed. With no chokes the beast fires in less than a full revolution. Very sweet carbs!

Getting off topic but ...I used to have a pair of FCR's on a '96 Duc M900, i think 41mm. It was an absolute scream from half throttle but a complete dog around town. It could not be run at low revs - it would either die or it would cough and splutter followed by an almighty raw fuel BANG in the exhaust.
Great at the time, but i'm older now.

I have a set of 41mm FCRs on my Ducati 900SS and they work great from idle to WFO. Indeed, it's at low throttle openings where they shine - incredibly precise fuel-metering. I can only guess that perhaps your low-speed jetting was off. As mentioned above, they do take a bit of dialing-in, even when supposedly "pre-jetted" for your application by folks who know what they're doing (Matt Rambow for my Norton; Chris Kelley for the Duck). I suppose there must be a fair amount of variation between individual bikes, and people naturally are conservative and err on the side of jetting a bit rich.

Brian,

you could well be right, i bought the bike 2nd hand with all sorts of goodies on it, incl FCR's, and I only kept it for a year - physically too small for me on anything longer than a test ride. At the time i assumed it was just overcarbed for the road so didn't play with the jetting.

Ok,thank´s fellows.I have still single VM36 round slide Mikuni on my cafe racer.Normally on cold she will starting first kick,same hot running idle speed very well.
I have PW3 cam and ported cylinder head,she is made only for road use,i had lot of problem yarly,the reason was glogged fuel oil filter.
many guyes said that sinle mikuni is enough,other ones have dual carburettors-is that dual set much more power than single-how about Mikuni flat slide carburettor(single)any experience.
It seems that on my bike single Mikuni working very well,but of course i would like get optimal power with one-that´s why maybe flat side could be better efect...

hey mr.norton!
i am thinking about the last months about changing my amal mk2s to flatslide carbs. if my carbs would be in good order i wouldn`t think about it.
but my carbs are realy in a bad condition. new mk2s are about 200euros each....so why not change to better technique for almost the same price ? YES!
so i did a research on the internet and had some discussions with a local dealer in my hometown.
i ordered 2 mikuni rs [34mm]....same od of the manifolds as the mk2s.....flatslide smoothbore carburetors....also with adjustable accelerator pump...imo do they look better than the fcrs.......
and: they cost almost the half of the price of the keihins! they will be about 450euros incl. VAT.....
I will get them next week....but i can`t test them `cause it`s deepest winter here in austria with too much snow!!!
when i have them tested i`ll post it with all the jetting and so on....
i am curious how they work!!!!

here are some informations about: http://www.mikunipower.com/RS01.htm

bye, chris

My 850 has a single 932 on it. runs fine. Starts easily. My 750 has a pair of 930's and also runs fine. I think it really depends on what you want to do. I don't blast around on my 850. I have a 41mm FCR on my motard and it absolutely RIPS. I also have a set of 41's on my 1040 FZR. It runs MUCH better than the stock carbs.