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brlawson

Wiring harness improvement/replacement

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There is so much electro-spaghetti throughout the V11, it isn't obvious looking at it on the bike, but look at the parts "fiche" and the two are clearly separate:

Page 10: "Electrical System"

Page 38: "Ignition Electrical System"

From having been fairly deep into these harnesses, it looks to me that the "Ignition" harness was installed on the production line early and the more extensive "Rest of the Wiring" harness installed over it.

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2 hours ago, docc said:

look at the parts "fiche"

...said in the voice of Obi Wan Kenobi

Thank you docc! This was a lightbulb (pun intended?) moment! Looking at the parts fiche really helps to make sense of it, and now the wiring diagram is clearer too. It seems like there are only a few wires feeding the entire EFI+ignition system, basically the ones coming out of two relays... Maybe one or two other stragglers, but at first glance it seems like that might be all it would take to move it over to the m-unit. Very encouraging stuff. Almost tempted to get started on it right now! 

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7 hours ago, sp838 said:

I wasn't aware that the harness was actually two physically separate entities, thanks docc. Looking at the wiring diagram, those two major systems seem entangled. Maybe the approach is to first rip out everything that isn't related to the EFI and ignition, and re-wire that, and then the rest might appear less opaque. I want to keep the EFI mainly from the "Sunken Cost Fallacy" cognitive bias: I already put time treasure blood sweat and tears into it. 

 

I know some people first hand who have done it with great success. Power gains and massive weight drop, simpler wiring harness and mechanical relibility. It's just very expensive - about $2500-3000 all in to do it right (carbs alone are about $1500)

As do I, in the racing world especially and it was never viable. It was always done by old school people that couldnt get their head around EFI and it turned out to be a joke. The primary reason you use EFI especially on a big twin is you cant get the power and the clean low end operation from carbs you can with EFI. Current big twins run 70mm throttle bodies and have huge power and good drive-ability. Show me a carb with 70mm throttle bodies that you can package in a twin that will give the required power and clean low down carburation.

A Guzzi MGS-01 a bike never designed to be used on the road by Guzzi and therefore no issues with emissions uses 50mm throttle bodies. Why didnt they just fit carbs if there was an advantage? Because it would be foolish to do so. Does anyone even make a 50mm carb that would fit and you still had a wrist strong enough to to lift the slides? 

I was around in the racing world when the Ducati 851 started racing in the 80's and a very well known tuner in Australian Superbikes ditched the EFI in favour of carbs and it was a joke nobody ever tried it again. Its basically a knuckledraggers mod, you know, like cutdown or removed mudgards. straight pipes no indicators and crossply car tyres type "custom bike" builders. 

 

Ciao

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I know the guys at Moto Studio personally. They convert V11 bikes to carb all the time. I seen the bikes in the metal, they run fine. The carbs of choice if money is no object are the Keihin FCR 41mm flat slides:  https://moto-studio.com/collections/builds/products/high-roller

This is a real world bike, as are all of their builds  Not trailer queens. 

The Dellorto PHM is the more budget minded route, also works just fine. Ignition provided by Sachse, comes with about 8 pre-programmed curves, you can have the box programmed for twin plugged heads if desired.

I have nothing against EFI. I think it's pretty awesome actually, especially for track/race bikes that you want to max out power and have no emissions fuel economy or noise concern with. My Daytona 675 puts out 118 hp with no engine mods, just intake and exhaust, a race alternator and some dyno wizardry by my tuner. For my Guzzi, the opportunity to drop 25 pounds while making the wiring harness more reliable is a serious consideration. But thanks to docc I think I may have figured out how to have best of both worlds. Simplified m-unit wiring and keep the EFI (for money reasons mostly)

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Drop 25 lbs by converting to carbs?
Sounds all kinds of whacky.

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On 8/8/2019 at 9:45 PM, Gmc28 said:

Sounds all kinds of whacky.

And yet, here we are. 

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On 8/9/2019 at 11:45 AM, Gmc28 said:

Drop 25 lbs by converting to carbs?
Sounds all kinds of whacky.

That's because it is. Carb conversions are generally done by two types, first group, the strip it down to the bare bones and bugger the common sense real world day to day useable bike and the second group that's incapable for one reason or another of getting their head around even the basics of a std EFI system.

The bonus is of course you get to spend around $700US to do the carb conversion when its all said and done to save a reputed 25LBS. Dont quite know where that figure comes from but there you go.

Ciao

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17 hours ago, Lucky Phil said:

That's because it is. Carb conversions are generally done by two types, first group, the strip it down to the bare bones and bugger the common sense real world day to day useable bike and the second group that's incapable for one reason or another of getting their head around even the basics of a std EFI system.

The bonus is of course you get to spend around $700US to do the carb conversion when its all said and done to save a reputed 25LBS. Dont quite know where that figure comes from but there you go.

Ciao

you can be such a ninny sometimes.

Edited to add: I do love you though. (and it's much much much more expensive than $700)

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Massive weight drop? Throttle bodies weigh the same or less than carbs. Fuel pumps aren’t that heavy. Where else you getting the loss?

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ECU and related wiring, the TB brace, various attachment points,  pump, fuel return line, 

it may or may not add up to 25lbs, but if one were to take very meticulous detail to remove any and all vestiges of the fuel injection system, it would add up to a net positive after subtracting the carb system.

I street raced a ‘77 Caddy Coupe. With the help of some friends, we chopped over 800lbs off that car. Had we known what we were doing, I’m sure it could have been much more. That’s after installing a 454 and TH400, 12 bolt etc...

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3 hours ago, Mikko said:

ECU and related wiring, 

I expect that you still need the ECU and 2 coils for ignition, unless you somehow fit a distributor system.

I always thought that EFI was a great way to avoid the "Guzzi Wave" where a rider tries to shake the cramp out of his right hand after hours of pulling against big carb return springs.

 

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3 hours ago, Mikko said:

ECU and related wiring, the TB brace, various attachment points,  pump, fuel return line, 

it may or may not add up to 25lbs, but if one were to take very meticulous detail to remove any and all vestiges of the fuel injection system, it would add up to a net positive after subtracting the carb system.

I street raced a ‘77 Caddy Coupe. With the help of some friends, we chopped over 800lbs off that car. Had we known what we were doing, I’m sure it could have been much more. That’s after installing a 454 and TH400, 12 bolt etc...

My moneys on NOT, by some margin as well. 

Ciao

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25 lbs. is a *lot.* If anyone wants, I can weigh the entire F.I. system. I have it in boxes from the Aero engine..

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I should probably clarify the origin of the 25 pounds claim and explain what it comprises, for those interested in this as well as for those who are in it simply because they enjoy getting into arguments on the internet :rolleyes:

The guys at Moto Studio are the ones who told me that that the stock wiring weighs in at around 25 pounds. They have built eight full ground up custom Guzzi V11 bikes of their own, not counting customer bikes. They know what the @#!#$# they are talking about. That said, in my comment above, I am sorry if I implied that the EFI system alone weighs 25 pounds. This thread is about improving and/or replacing the -entire- wiring harness. The 25 pounds number is for the whole stock wiring system, and I imagine they also included the handlebar switch gear in that number. Maybe even turn signals and tail light? So anyway, at least the relay blocks, fuses, many many yards of wire and plastic harness tubing, weatherpack connectors, sensors, switchgear, ignition switch, the ECU , throttle bodies, injectors, throttle body rail and linkage with the TPS and fast idle warts, fuel pump etc...

 

I imagine all of that does indeed add up to 25 pounds pretty quickly. That isn't what the net weight loss would be of course, since after removing all that you'd have to add back a set of carbs, an electronic ignition, an M-Unit, new switchgear. All of that stuff would be significantly less though. Both in weight and in clutter. Is it something that everyone with a V11 should do? Absolutely not! No one ever said so. But then, go through the forum and count how many posts there are on electrical problems with these bikes. Chuck just went through an ordeal with his. Then come back to me and tell me it wouldn't be worth it to rewire the bike from scratch. Hell, keep the EFI. The point is to make a simpler, more reliable electrical system.

So again, my apologies for not being clear in my previous comments, I hope this makes sense. And for those who are in it just for the joys of getting into internet pissing matches, well, I can't help there. That's between them and their therapists and/or liquor cabinets.

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