Bimota Forum

[hindsight]

Hi Glen -

The lambda (actually, it's a wideband O2 sensor, but most folks know the phrase "lambda") is fitted to the horiz downpipe, and I'm not planning on fitting one to the vertical. I'm currently planning on using it for tuning the ST2 fuel map, but I've recently been doing some more research, and I've found that the ECU software can run in closed-loop mode, which would mean that the sensor would need to be a permanent fixture. Haven't made up my mind on that yet, we'll see how we progress.

It's only fitted to the one cylinder, on the assumption that both are pretty much equal.. as you'll know, more modern machines have sensors fitted to both, and that'll pick up things like variances on combustion and injection, and compensate for each cylinder - that's not currently on my agenda for the DB2 though.

[welshlamb]

Well so far I have to say your capabilities and ideas generation leave me gobsmacked. I'm afraid Im another dinasour that likes to see things to understand them so electrics, electronics and software test my patience to breaking point. Fascinated by this all the same so watching the threrad closely!!
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Not as many bikes as I would like and already too many to keep up with!

[hindsight]

Thanks for the kind feedback guys, really appreciate it. I'm thoroughly enjoying this journey too

And truth told, a year ago I probably wouldn't have done much of this, mainly due to lack of time. There's definitely something to be said for a slower pace of life.

Hoping to spend some time in the workshop over the next few days, and to confirm the O2 sensor to be operative and start the bike on the ST2 fuel map for the first time.

M.

[glened]

Hi Mike,
Thanks for the reply with regards to the O2 sensor, I quite like the idea of making it simple with the use of one sensor.. Your mantra on changing just one item at time is spot on, just in case you have to re trace your steps. The ECU case looks very impressive, could you use it directly from being printed? is the enclosure strong enough or do you use it as a prototype to get one injection mounded. Enjoying the thread whatever the outcome.

Regards Glen
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Bimota DB10, Suzuki TS250, Kawasaki Z1A, T120 Trton, AJS650, KTM690 Duke

[hindsight]

Yes, the case is definitely strong enough to be used directly as-is from the 3d-printer, so no worries there.

I had the bike running on the new injectors yesterday afternoon, though I was curiously getting a lot of backfire on the horizontal (in the exhaust and throttle body), so I'll have a bit of troubleshooting to do there. I wonder if one of the new injectors is playing up?

I'm going to first try adjusting the timing of the injectors, then perhaps swap the injectors around to see if the issue follows the H injector. I could potentially pull injectors from my 888 to for testing also.

Interestingly I think the new injectors has also solved another mystery that I was aware of: when I swapped the original exhaust for the carbon one, I noted that the temperature of the exhaust gasses were significantly different between the cylinders, with the horizontal being far cooler than the vertical. This wasn't measurable with the original exhaust, as it had the 2-into-1-into-2 collector that mixed the gasses on the way out.

With the new injectors, the gas temperature now feels more or less equal.. so I'm thinking that one of the old injectors may have been constraining flow, leading to a reduced combustion..

[barnmankit]

Hi folks, I hope you don't mind me chipping in with some thoughts on fuel injection and the associated electronics and good old fashioned carburettors. This is an interesting subject because carburettors had reached a very high level of refinement and functioned very well with minimum maintenance, and moreover the carburettor is an autonomous self-adjusting device with no need for external sensors or complicated computer programs. The Keihin FCR41s on my DB2 are brilliant performance carburettors (although they sacrifice some ease of use for street riding). Fuel injection, although potentially offering finer control, depends on many external sensors (some electro-mechanical, all working perfectly), an electro-mechanical injector constructed to very fine tolerances (or not), a fuel pump subject to wear and breakdowns, impeccably designed computer programs, etc, etc. Is the massively increased complication worth it for the small benefits in terms of control (excluding emissions regulations - the original impetus for the introduction of fuel injection)? We shouldn't forget that the carburettor is a brilliant concept which reached a very high state of development. I should add that my opinion is coloured by problems I suffered with a Mitsubishi direct injection petrol engine which were beyond the diagnostic powers of Mitsubishi official workshops.
In admiration of your project and wishing you success!
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1998 Bimota DB2 edizione finale naked
1976 BMW R75/6 tractor (for sale)
ICE recumbent trike
A shed full of bicycles

"We're each given one small grain of madness - if we lose it, we're nothing." Robin Williams

[hindsight]

I think it's absolutely a fair point and it would be a mistake to not recognise the elegant simplicity of the carburettor.

As the number of "critical" components required to make a motor run increases, so does the likelihood of a failure causing an interruption. All we can do (and hope that the manufacturers also do) is to build with paranoia to increase the mean time between failure on all components, along with sufficient proving.

[TVRRICH]

Barnmankit has your FE had the FCR41 carbs on from new. My FE has them on too, in the for sale bumf for my bike it stated they were "factory " fitted and i have always wondered if this was correct. It would be interesting tosee if many more DB2 FE's on here had them on and if it was from new

[barnmankit]

I retrofitted the FCRs after buying them from Allen's Performance Products pre-jetted for Ducati 900 motor. Previously the bike (no. 064) had the standard Mikuni fitment. I can easily achieve 60mpg during fast riding on mountain roads with these carbs. Safe riding to all of you.
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1998 Bimota DB2 edizione finale naked
1976 BMW R75/6 tractor (for sale)
ICE recumbent trike
A shed full of bicycles

"We're each given one small grain of madness - if we lose it, we're nothing." Robin Williams

[2bims]

TVRRich….BarManKit et al......My DB2 has Allens PErformance Keihin FCR41 Flatslides also fitted....albeit retro fitted to the bike in 1996 when a 944CC big bore kit was added to it....V2 HiComp billet pistons...stage 2 cams.....etc etc....20-25mpg is my limit on that....30 if totalling along....although the bike is happy to do that....the rider isn't.....K&N's...flatslides and Moto Corse end cans says she sounds and runs better at full chat...

TVRRich….isn't yours kitted with FCR39's? from recollection of the advert at NLM?.....it is stamped on the left side body of the carbs on the LHS showing through the fairing....

I understand why folk put FCR41's in....as theres not much price difference between the 39's and 41#s...so...folk go bigger coz bigger is best right?...All the mods and reports I've ever read though say its not worth going for the 41's UNLESS you go the whole route with the big bore kit also.....so I imagine if FCR41's are fitted to a standard motor...then maybe they are jetted down to suit....

Factory standard or after?...Anyones guess that....I've never seen a "Sales Brochure" for the DB2FE.....and they made what?? 50?.....Bimota were famed for speccing a bike how you wanted it if ordering direct...and also for throwing on whatever parts they had available to finish a bike off....What colour are the engine casings in the FE?.....If silver greyish it would indicate the engine out of the DUcati Monster 900 from around 98/99.....as used in the DB4......as Bimota wanted the DB4 to be carbed…..and Ducatis "similar" offering of the 900SS had gone fuel injected in 98/99.....whereas the Monster was still carbed...If crankcase covers are Black.....then its the 900ss Engine from up to 1998...which remained carbed up until that period....and they evidently had Mikuni 38's on them...DB4 was offered with the "corse kit" which included FCR39's and a MotoCorse end can....no reason why they couldn't offer FCR's on the DB2FE....

Other than starting from cold.....which takes time due to no choke.....mine have needed no work from the 10 years of my ownership....and they were fitted to the bike in 1995......and just needed a clean after I bought the bike...Best mod that can be made to any Ducati engine of that era...Keihin Flatslides....

[TVRRICH]

These are mine.[img][/img]

[TVRRICH]

[img][/img]

[2bims]

Yup.....FCR41's....."Motorcycle Race Use Only".....I kept the sticker on mine also.....Interesting Push/pull twin cable routing you've got there....feeding from the throttle assembly to the Right of the carbs and across...….Mine I fed across the front headstock, through a triangular hole in the frame and down to the pulley assemblies on the Keihin Carbs which are on the Left hand side of the carbs

[2bims]

Oh...Do you want to sell your Fuse box cover?...Mine fell off a while back...and when I retraced my route I found it....crushed by car wheels many times over....I've "sort of" fixed it...but its very worse for wear...I havent found a replacement yet for it...as its not the ruddy same as the Ducatis of the era...grghhhhhhhh

[TVRRICH]

Sorry 2 Bims, not for sale. Mind you when i had my Battery escapade recently and had to remove the fuse cover it didnt feel exactly very secure so it must be a fault with them. Do i take it you have no idea what its off ?