retro fitting carbs for 02 LeMans

[Guest Warren Rhen]

I've had 2 previous Guzzi's. Both 1000 SP's. Both rarely ever got less than 45 MPG no matter what the driving conditions. I'm tired of this 30 MPG crap with this new LeMans. I also have a Gran Canyon with FI and it gets at least 10 MPG less than my carburated 900SS. So I'm considering reverting back to carbs and electronic ign. Has anyone done this and what will I need other than carbs, manifolds, and cables? I'm thinking probably keihen flat slides probably 41 -42 MM. Whats the best way to go with the ign?

[docc]

It makes me wonder how the ECU will set the igntion mapping without input from the TPS ? ?

[al_roethlisberger]

Yeah, this is pretty tricky as unlike older bikes, there isn't any way to add a distributor, etc to the V11 engine. AFAIK, it doesn't even have a drive gear for a distributor .... so you'll still have to use the ECU for timing and ignition.

 

I've seen this idea floated around on the Wildguzzi and Guzzitech forums a few times, but after it is all said and done, even the old-schoolers that grew up with carbs end up convincing themselves that wouldn't go back to carbs. You might want to ask this question and/or search for an old thread there for their insight.

 

I think they found that when well-tuned, the flexibility and performance of the EFI trumps carbs.

 

Keep in mind that over time, and as the bike loosens up, MPG will improve with the EFI bikes. But it is also true that I've seen many carb'd bikes of the same model that later went to EFI, get better mileage

 

al

[Steve G.]

We should all remember that these injected bikes are making more power than the old carb equiped bikes. And as an internal combustion engine is basically a self powered air pump, if it is putting out more power, it is easy to assume that it is using more fuel to make the higher power.

I think 30mpg is a bit low for these machines, but that is not much less than alot of high output new bikes these days. It seems like a whole bunch of money to get another 10mpg. Have you checked the cost of new Mikuni flat slides? WOW!

My bike really needed some mileage before it loosened up, needing less of it's own power to spin. I'm 38-45mpg/us gallon now, and happy with it. You wouldn't want the fuel bill of my cbx, maybe 25 to the us gallon, and it is dialed in very well.

Ciao, Steve G.

[Cliff]

Both my bikes get better than 5l/100km or 20km/l on my near legal weekend rides.

 

Bad economy is not a function of FI/carbs, its an indicator of bad tuning. Unfortuantely the powers that be have made it pretty awkward for endusers to tune standard FI vehicles.

[Murray]

I have 41.5mm kelien flat slides on my 1100 sport, you are unhappy with 30mpg are you? Try between 9.5kms per litre and 17kms per litre. To get 17 kms per litre you have to really pat it flat ground little overtaking, They have been professionaly jetted in normal is 13-14kms per litre. As you havn't said weather you are speaking of the imperial gallon or the US gallon I'll let you sort out the coversions. The delorto's are no better the fuel injected bikes are vastly better remebering things improve with run in. There is definatly no cog on the cam to drive the distributor even on the carbed 1100sports/cali 1100's let alone the fuel injected bikes. Fuel injection genrally gives better enconmy and definatly more consitant. Before you ask the Kelien are a vast improvment on the delorto's and are matched to a full termi race exhauts system and yes the sound is to die for. The 1000sp's have a very mild cam small valves in the head much more leniant emission laws and as someone else pionted out have a fraction of the preformance the V11 Lemans have.

 

In short I severly doubt carbs will improve anything and its very likely you will go backwards not to metion a very expensive exercise. For the kind of money you are talking about you can buy a full Motec ECU for your bike which is infnetly user tuneable. Alternativly cliff produces a intresting device for less than what they ask for a power crapper.

 

BTW I am sure some of the Europeans would be intrested in what you actully are paying for fuel.

[belfastguzzi]

BTW I am sure some of the Europeans would be intrested in what you actully are paying for fuel.

Good point!

[Guest friz]

WARREN THEIR IS NOTHING LIKE FUEL INJECTION YOU JUST NEED TO DIAL IN THE GUZZI I JUST GOT BACK FROM MY DEALER ON THE BUBBLING ENGINE CASES WHERE I GOT 47.9 MPG AT THE SPEEDS BETWEEN 70-100 SO GO DO SOME ADJUSTING!!!!!

[Guest John T]

Remember that if you are riding in cold weather, the FI thinks the bike is cold (as in just started) and it will run very rich. When it gets warm out, the FI will lean out and mph will rise. If this is still happening in warm weather, the FI needs to be leaned out. A good dealer might be able to help, or a power commander and a custom map will get you in the 40mph range.

 

Stick with the FI, way better than carbs.

[belfastguzzi]

Remember that if you are riding in cold weather, the FI thinks the bike is cold (as in just started) and it will run very rich.

I've been wondering about that. So far I have been only riding in cold weather. Acceleration can be rough with hesitation through 5,000 and 6,000 rpm – just where you want it to be smooth. Most of my winter journeys have been short so I can't really tell how much things change with warming up over a long trip.

 

I've never had a bike with EFI before. Cars seem to drive ok from start in the cold, but I suppose they don't have all their bits hanging out.

 

When out this afternoon, I would say the bike was a bit rough accelerating around 5,000 rpm for about 20 miles. I'm not sure when/if it smoothed out, but that would indicate that it probably was better after 25 miles or so and therefore I didn't notice it.

 

Does that fit with your experience of warming-up symptoms in cold weather?

[al_roethlisberger]

In short I severly doubt carbs will improve anything and its very likely you will go backwards not to metion a very expensive exercise. For the kind of money you are talking about you can buy a full Motec ECU for your bike which is infnetly user tuneable. Alternativly cliff produces a intresting device for less than what they ask for a power crapper.

 

 

I love Cliff's work, but just to be clear, his My15 ECU is right at twice the cost of a PCIII

 

al

[Martin Barrett]

I allways wondered why I have a choke lever fitted with EFI. I assume its because there is a sensor reading air temperature in the air box but nothing reading the actual engine temperature. So the bike can't make any adjustments for cold starts.

I've not experianced the rough running mentioned above. I tend not to ride when there is snow or ice on the ground, but otherwise have done so .

From memory I think 6 degres celcius is about favorite for icing, allows a good degree of moisture to be held in the air and any drop in pressure over a venturi will allow ice to form as the temperature drops at that point. I might be mixing up carb icing and wing icing.

I would like to think that there would be enougth heat flowing back from the cylinders to keep the throttle venturi clear. But obviously not in every case as kawasaki had a big problem in the late 80's with the introduction of watercooling.

[Murray]

    In short I severly doubt carbs will improve anything and its very likely you will go backwards not to metion a very expensive exercise. For the kind of money you are talking about you can buy a full Motec ECU for your bike which is infnetly user tuneable. Alternativly cliff produces a intresting device for less than what they ask for a power crapper.

 

 

I love Cliff's work, but just to be clear, his My15 ECU is right at twice the cost of a PCIII

 

al

Cliff charges around 5-$800 AUD for his devce depending on how handy you are with a soldering Iron. 800AUD+ is what they are asking for the USB power commander III which is not a closed loop system how much do you pay for the power crapper (remebering figures are in Australian Dollars).

[Cliff]

I allways wondered why I have a choke lever fitted with EFI.

Its not a choke, its a fast idle.

Cars usually add a soleniod in to do the same thing.

[Cliff]

I think there where some "limited run" PCs for around US$150 for a while. Don't know if thats still the case. There's also a run of 2nd hand PCs from those upgrading to the USB version.

 

The annoying thing is you shouldn't need them at all with the 15M as you should be able to flash map the ECU. Even stranger, you buy an aftermarket exhaust and they give you another ECU.

 

I should do what these guys in europe do and charge euro200+, just to change your ignition map. Although I'm not comfortable charging people for nothing.