Ducati 900sl Keihin 41 Fcr/ Exactfit Ignition Coil Upgrade From Ca Cycleworks.

From what I have read most people that have fitted Keihin 41 FCRs ended up with flooding troubles........but someone (sorry, can't recall who) on here solved the issue.

 

My recollection as an ex SS owner and member of the SS Yahoo group is that the first step is to open the airbox, fit slip-ons and install a jet kit. The Desmodue was a lovely but noisy and dirty motor that Ducati had to strangle to get through noise and emissions regs. The above eliminates most of the strangulation and makes for a much nicer bike to ride.
Next step, which I also did is to install a CCW coil-kit which gives better throttle response and a much steadier idle and low-speed running and pick-up. It also eliminates plug-fouling.
Next step is then the FCRs, which as I had a 750, I could never justify. I can't say I ever heard of the flooding problem, People generally raved about them.
Next step towards real power is a big-bore kit - 944?? After that, it's head work but you are starting to get into diminishing returns. Chris Kelley reckoned 100 bhp was achievable though.

 

There were several people on the old Ducatisti website that had problems with FCRs and I think the guy on here cured some of it with an electric cut-off valve.

 

Fitting FCR's transforms the bike, I recon it's one of the best mods you can do to an old SS. They're easy to fit, only a bit of cutting to the battery box area for the cables and if my memory serves me right CCW will jet them depending on what kit you have on the bike. Cut the top off the airbox, fit a K&N filter and open pipes and you'll be grinning like a Cheshire Cat ; )
Have heard a few stories about carb flooding over the years but haven't had it happen on mine, something to do with the fuel pump pressure I believe...
Ian.

 

I've got FCR 41s on my Monster, although they are the split-single carbs on short intakes which require a little more work and parts to fit than the banked pair.

I can't compare to the original carbs because I built my bike with these and a few other mods (944cc, HC pistons, gas flowed heads, ST2 cams, ignitech, dynacoils etc.) but I can say that the power delivery is brutal, it makes strong low-down and mid-range power - up to 6k rpm it makes my 916 feel slow and although it loses out after that it still makes over 90hp at 8k.

I did fit an electric fuel tap, wired in conjunction with the fuel pump so that it can't leak all the fuel into the cylinders whilst sitting in my garage overnight (have heard of a few that have done this) and have had no problems otherwise.

As I said I can't compare to standard carbs, but I'd be surprised if a standard bike pulls anywhere near as strongly as mine...

 

Gotta love torque...

 

I would certainly go for FCRs but also worth considering the 39mms, especially on an otherwise standard engine.

I've had one instance of flooding, which put lots of petrol into the oil. Spotted it before startup so just drained and refilled and sorted out the leak ... which turned out to be a tiny sliver of float bowy bolt O ring stuck in the needle valve (I'd had the float bowl off).

Bought mine from Power Barn .... gave Mike the engine spec and I've not touched the jetting since taking them out of the box. Lots of spare jets in the kit, though.

My bike has 39s, hi-comps, ignitec and mini-dynas and used to go like a train until I decided to make it go like a plane. Now it's gone to Wiltshire for a facelift and I'm wondering when I'll see it again.

 

What everyone says about FCR's is absolutely right - the biggest single improvement you can make.
Not so convinced about changing the coils - haven't found much wrong with the standard ones

 

My SS was a snatchy, recalcitrant beast that refused to trickle along without lots of feathering of the clutch until I changed the coils. It also had a habit of fouling plugs and that stopped completely.

 

Not sure if you realise this but @Exige on here is now importing products from CCW and that makes an enormous difference to the price you'd end up paying for a personal import. He is also giving a 15% discount on top of that to forum members .
The website is www.exactUK.com

 

Indeed, although it makes a few lbs/ft less than the 916 it does it 2k rpm lower down. That, combined with the lower weight and less forward weight distribution makes it much more lively up to around 80mph.

For anyone interested, this is the fuel shut-off valve I used; http://www.ebay.co.uk/itm/221203801425?_trksid=p2060778.m1438.l2648&ssPageName=STRK:MEBIDX:IT it's small enough to fit easily, brass bodied so should last well, reasonably priced and has a manual override in case the electrical side fails - works great.

 

I have wondered how it would be, if in MotoGP, they were to cap bhp but allow unlimited capacity and/or torque...

 

I am indeed but he appears to be in South Africa :smile:

 

So he is... :Shamefullyembarrased:

 

I had 41's on my SS. All I will say is rolling road.

The other thing to bear in mind is that they are racing carbs so no chokes and also don't be at all surprised if as part of the bikes annual birthday you check over the carbs as part of the duties. The float needle wears out quicker than other regular carbs. As you're going for ignitech as well, I can give you some links for adaptor plates for a TPS if your provider won't supply it as part of the carb.

On average look to lose half a day in rolling road setup cost in the price.

When your float needles wear out you can get anything from cylinder flooding through to half of your tank ending up down your exhaust pipes and on the floor as I did.

As there is no constant velocity how much and fast you crack the throttle open is how much and fast you'll lift the slides, and what you'll find is you'll develop a silk glove feel. Early on in your FCR apprenticeship you may well flood the engine in certain gears.


In return for this expense you'll be reward with one of the most wonderful soundtracks ever. The induction roar is sublime and the slides like the rest of the bike will chatter with a music of their own.

The throttle response is wonderful, and the benefits in midrange will leave a massive grin on your face.

The desmoquattro boys think they have it all with their engines, but there is still something wonderfully spine tingling about the mechanical symphony that is a 2V on FCR's.



(hopefully the video link should work - complete with wheelybin and cat litter tray shots!)

 

Agree with everything Sev says (except I haven't experienced any flooding problems (yet)).
Wish I'd known about the availability of tps adaptors - ended up making my own.