chatting on Sunday with Richard from louighi moto and some guys at VMCC meetup who all race 750ss and 900ss in various road races such as Aberdare and olivers mount as well as track races and none of them use keihan FCR carbs they use Mikuni BDST and say that the keihan FCR is a waste of money as the mikuni BDST has advantages and can be tuned just as well ,, i know that Alf always favoured FCR in his race bikes , ???????? When i used to tune Carby HS sporsters for max power and races I found the Keihan FCR , S&S etc to be inferior to The Lectron ,,
An interesting chat about carbs
- Thread starter jerry
- Start date
900Rebuilder
Registered
If Lectron's are being used I wonder if those new Smart Carbs will ever see the light of day on a Ducati as they seem very popular already in the two stroke community
Smart carbs have been fitted to a 1976 900 Bevel in USA and a norton commando so probably could be used on Belt drive Ducatis
900Rebuilder
Registered
These - https://smartcarb.com/WTF is a smart carb? Does it wear a suit and tie?
I had a pair of chromed concentrics on a Bonnie once... they were smart.
Well! I cliqued on your link and very nearly didn't go any further than the heading "Fuel what excites you".
Apparently I could get over 100mpg from my old Triumph if what they claim is true, but at £450 a pop, even without the postage from that mythical land between the Gulf of America and the Lake of America.. Nah!
Of course I don't have a patent rod metering system, just a nigh on 70 year old wrist which gives me 80mpg, when I'm actually stooping to using petrol.
One smart carb what will stay on the shelf.
Apparently I could get over 100mpg from my old Triumph if what they claim is true, but at £450 a pop, even without the postage from that mythical land between the Gulf of America and the Lake of America.. Nah!
Of course I don't have a patent rod metering system, just a nigh on 70 year old wrist which gives me 80mpg, when I'm actually stooping to using petrol.
One smart carb what will stay on the shelf.
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I have an inbuilt aversion to anything which calls itself "smart".
Its a somewhat hollow boast which can often belie what lies beneath.
I give you those dangerous new motorways as an example.
And those ultra-short wheelbase, small-wheeled cars which can't cope with bumps in the road.
As for an "algorithmically designed venturi".
Well how else would you design one, other than by using a "series of mathematical calculations" (an algorithm).
Both terms stink of contemporary marketing technobabble.
Which is a shame because it puts me off before I've given them a chance to prove their worth.
Whatever happened to Gardner carbs ?
As for flatslides, the only reason I bought a pair was because their direct-pull slides a purport to overcome the carb icing that the vacuum-pull std carbs are susceptible to.
Well that and the fact that a pre-brexit discounted price deal was too tempting.
They're still in the box though for now, so I can't comment further.
Its a somewhat hollow boast which can often belie what lies beneath.
I give you those dangerous new motorways as an example.
And those ultra-short wheelbase, small-wheeled cars which can't cope with bumps in the road.
As for an "algorithmically designed venturi".
Well how else would you design one, other than by using a "series of mathematical calculations" (an algorithm).
Both terms stink of contemporary marketing technobabble.
Which is a shame because it puts me off before I've given them a chance to prove their worth.
Whatever happened to Gardner carbs ?
As for flatslides, the only reason I bought a pair was because their direct-pull slides a purport to overcome the carb icing that the vacuum-pull std carbs are susceptible to.
Well that and the fact that a pre-brexit discounted price deal was too tempting.
They're still in the box though for now, so I can't comment further.
Mark64
UKMOC Member
I can't believe you've got flatslides and not fitted them, they are the best modification you can do to a Monster, night and day difference, or if you aren't going to use them and you got them at a good price, cash them in because they are real spendy now ;-)
Yeah, I get that.
But the bike's always been a keeper so I do tend to take a long view.
I bought the flatslides when I used to ride a lot more in carb-icing conditions.
I much prefer bits for the bike to cash.
But the next big job really ought to be front suspension.
Then maybe the flatslides.
But the bike's always been a keeper so I do tend to take a long view.
I bought the flatslides when I used to ride a lot more in carb-icing conditions.
I much prefer bits for the bike to cash.
But the next big job really ought to be front suspension.
Then maybe the flatslides.
900Rebuilder
Registered
As you got them carbs for a bargain price Utopia I'd hang onto them and keep them in the spares dept.
RichardDDuke
Registered
I've got a pair of FCR flatsides 39mm which are in need of a good clean as they stood unused for about 8 years.
I've got a carb rebuild kit from MX in Holland that I'll be using when I do strip and rebuild the carbs. I know the jets were "adjusted" by Baines Racing when the carbs were fitted in late 90s as they reckoned that Ducati Kaemna always set them up lean. However, what they actually installed I've no idea as the mechanic said he modified / drilled a jet as it needed a non-standard size.
...So, does anyone have any recommendations as to what jet sizes run best in FCR 39s on a 944cc 2V engine then please let me know. Hopefully they'll be close to what I find when I strip the carbs down.
I've got a carb rebuild kit from MX in Holland that I'll be using when I do strip and rebuild the carbs. I know the jets were "adjusted" by Baines Racing when the carbs were fitted in late 90s as they reckoned that Ducati Kaemna always set them up lean. However, what they actually installed I've no idea as the mechanic said he modified / drilled a jet as it needed a non-standard size.
...So, does anyone have any recommendations as to what jet sizes run best in FCR 39s on a 944cc 2V engine then please let me know. Hopefully they'll be close to what I find when I strip the carbs down.
Each setup is specific to the bike in question but, there seems to be a decent amount of 'adjustability' with them.
Mine has split-single FCR41s which I bought from a US supplier with 'standard' Sudco jetting for a 900 engine.
Like yours, mine is a 944 and I had the heads & ports gasflowed, short intakes, High Comp. pistons etc. and it ran lean with the carbs straight out of the box, popping and farting excessively on first startup.
I took it to SPR Racing (who were excellent BTW), https://www.sprracing.co.uk/ to get it setup on the dyno and we only needed to increase the main jets from 155 to 165 and, at the time I could get the jets locally from Allen's Performance (sadly closed down now) but everything else could be optimised using the various adjustments.
But, as I said all bikes will be a little different and mine are 41mm anyway so probably not much to reference there.
Worth contacting SPR though as they have plenty of experience with FCRs and Ducati and were very helpful, highly recommended.
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Im not averse to FCR flatslides for one of my 750s but i cannot justify over £1800 or more UK price ,,,, when they are available for a fraction of that price in USA .. if i was still going to USA I would pick up a set , when carbs cost more than the bike they are on thats plain silly
crust
rattles when he walks
I fitted a pair of FCR41s to my Monster and was amazed at the performance increase, a lot better mid-range. A pleasing bonus was better fuel economy. In my experience a well worth it upgrade - caveat being I bought mine on ebay a fair while back when they were a lot cheaper.