98 cali ev EFI to Carbs question how to.

[arveno]

HI !
I have a 98 cali ev and i would like to convert to carburetors.
Can someone please explain me step by step how to do the conversion ?

Things I know :

The canisters and all the hoses are gone already.
i assume i have to take out the fuel filter,fuel pump,fuel pressure regulator and the throttle bodies .
i already got a gas tank from a carbed bike ( mille GT )

I think i should leave the ecu that will function as ignition ( to time the engine ) is this correct ?

next: get a set of 36 mm carbs ( i can get a set from a 1000 SPIII ) Can i use the manifold that are already on the bike or do i have to buy different one ? which one ?
Does anyone know what would be a good starting point, jetting set up for a 36 mm carb in a 1100 cali ev engine ? ( main jet,needle etc? )

what else ?
Am i missing anything ?

Thank you so much .

note : please , i hope this thread is not going to turn into another carb vs efi thread. seriously.

[Wayne Orwig]

Odd thing to do aside.
How about putting a DigiPlex system in for the ignition. It will trigger from the sensor under the right throttle body. Made just for that bike.

Then using the EV tank, just plug the fuel return hole. Shouldn't even need to change the tank unless that is part of the 'downgrade/upgrade'.

[arveno]

Odd thing to do aside.
How about putting a DigiPlex system in for the ignition. It will trigger from the sensor under the right throttle body. Made just for that bike.

Then using the EV tank, just plug the fuel return hole. Shouldn't even need to change the tank unless that is part of the 'downgrade/upgrade'.

why should i us a digiplex instead of leaving the ecu in ?
Space ? or any other reason ?

this one ?
http://www.stein-dinse.biz/Complete-partlist/Unsorted/electronic-ignition-Digiplex::131401.html?language=sc

Sorry not very savvy here in term of electronic stuff....

thanks

I already have a gt mille gas tank , that's why i want to use it... i kind of like it better.

[v65tt]

i have fitted a v7 Stone efi engine to my 1984 V65TT with Carbs and sache electronic ignition

Best to dump the factory ecu as without the throttle position sensor moving in proportion to the throttle the ecu wont advance the ignition properly

i can highly recommend the electronic sache ignition system

http://wildguzzi.com/forum/index.php?topic=81033.0

[guzzinka]

I feel like I've seen different information on what input the ECU needs to trigger the ignition - does the ECU need the TPS for the ignition or not?  For what it's worth, I too like the idea of a carb conversion. I doubt anyone here would disagree with FI being superior for some situations and carbs being superior for others.

[guzzista]

Funny thing , I was thinking of going EFI on my 94 Cali Carb as I liked how my 95 Cali with EFI ran and got great fuel mileage . Arveno , if you decide to proceed with your conversion, maybe we could talk swap?

[v65tt]

I have only played with the current V7 Stone/ Racer engine with carbs,  if you look at the ignition map it advances on throttle position as well as the rpm

Disconnect the TPS and point a strobe at the flywheel or alternator with a test marks made and compare how far it advances compared to the advance with the TPS connected

[Wayne Orwig]

why should i us a digiplex instead of leaving the ecu in ?
Space ? or any other reason ?

this one ?
http://www.stein-dinse.biz/Complete-partlist/Unsorted/electronic-ignition-Digiplex::131401.html?language=sc

Sorry not very savvy here in term of electronic stuff....

thanks

I already have a gt mille gas tank , that's why i want to use it... i kind of like it better.

The vacuum port that you see on the Digiplex manages the spark advance, instead of needing the TPS.

[Chuck in Indiana]

Can you put a distributor in the 98s, or did they block off the casting by then?

[Cliff]

You can not use a Digiplex ( these would be hard to replace if they failed anyway) as it requires 5 lugs on the crank whereas the ECU used 4. As already mentioned it would normally need a vacuum connection to adjust spark.
The ECU also needs a valid TPS as this is used to determine spark advance.

You don't give any reason for wanting to do this. My advice ( which is the same as I gave someone recently wanting to go the other way ) is don't. The benefits (if any ) will most probably not make up for all the effort required.

[pehayes]

I have a friend who did this but is not a subscriber to WG.  He wrote back and authorized me to post his comment.  Let me know if you want to get in direct contact.  See below.

Patrick Hayes
Fremont CA
-----------------------------------------------
Hello Pat. You can copy and paste with my signature.
I ran a Late V1100 Lemans motor in my MK4 Tonti for a good 10,000 miles with the 1000 Lemans 40mm Dellorto's so very familiar with the topic. Your desire to swap to carbs is an easy and there is plenty of justification to doing so. It's all what one likes. Your biggest hurtle is the ignition. I used the stock 15M for sparks and it worked fine. I'm told the stock ign has a 3 dimensional map, and uses the TPS, along with the phase sensor (RPM) to determine advance rate relative to load. I can guarantee you it will advance w/o the TPS, at least mine did with the 15M. You have the bulky 16M but I'm sure it's functionally the same. I suspect the TPS does have an influence on the rate of advance relative to throttle position but likely not a lot. Think advance on an old school distributor. There is no load sensing, just an advance mechanism controlled by RPM. It has no ideal how quickly or far the throttle is opening. Cars used vacuum advance which could kick in a few extra degrees at low load, however that was more for fuel economy. That being said, there are very good alternatives out there for sparks. The stock ECU has no provisions for any timing adjustment which is also great motivation to Chuck it!  One of the nice advantages of carbs is you get to liberate your bike of all the crap. Fuel pump and plumbing, filters, pressure regulator, all the sensors, and oh yea, the huge ECU along with the bulky wiring harness. Do you really want to keep the ECU and bulky harness just to keep the non adjustable stock ignition? I vote to dump it all and go with a stand alone ignition. You can sell the stock ECU to help fund the new ignition. Regarding the harness, in my bikes case the EFI harness was a sub harness and easily integrated into my old Tonti harness. I'm guessing the reverse can be said for yours on its removal. On the actual carb swap I would get together with the guy who wants to swap you. You have everything he needs and visa versa. One thing you will miss is the minimal throttle effort with EFI vrs the brutal pull with Dellorto's. I used a dual cable Daytona throttle and had Motion Pro make me custom cables which eliminates the factory splitter, along with lighter springs and its as smooth as it gets. In the end I eventually went with the full EFI swap and never looked back. It was a lot work fabracating everything and yes it's cluttered, but it does work great. I'm fighting some conditional pre ignition at the moment, which BTW could easily be resolved if the timing was adjustable!!! I have one of Cliffs MyECU sitting on my toolbox which will solve that problem for good!
Have fun and reach out to me if you have any questions or concerns.
Mike Sorge

[Antietam Classic Cycle]

Can you put a distributor in the 98s, or did they block off the casting by then?

Looks like there was a blanking plate over the hole, but I can't tell for sure if the camshaft still had a "distributor" drive gear or not.

[Chuck in Indiana]

Looks like there was a blanking plate over the hole, but I can't tell for sure if the camshaft still had a "distributor" drive gear or not.

I *think* that if it was just a blanking plate, the drive gear is still on the cam. That would be a simple option, if so..
All a guy would have to do is pull off the plate and have a look.

[jacksonracingcomau]

I did it to a 95 with blown ECU
1/ manifolds from LM 12 or 3 for 36 carbs
2/ had to bore hole for points drive gear and fit early Cam
Along with some diet, extra plugs and bit of care it is excellent, 20k miles on it now
Only experiments have been 40 v 36 carbs. 40's better everywhere with matched manifolds

But I did think Cliff's my ecu box ould work with flywheel trigger (2 lugs on 95) , if not , I am certain someone sells box of tricks that would or fit complete crank driven ig that goes on front like v75 TT above (same alternator)

Wether worth it or not is entirely subjective, for me, no question, has never pinked or missed, no issues whatsoever
As experiment I'd like to try 2 ig triggers, points for inside plugs, crank trigger for outside,, different timing, but the cost / effort says I prob never will, is too good as it is to mess with

[Cal3Me]

JB,,,,has done a couple of carb conversions. Maybe he'll chime in at some point.

[guzzista]

Looks like there was a blanking plate over the hole, but I can't tell for sure if the camshaft still had a "distributor" drive gear or not.
[/quote] ....  Looked inside my 94 Cali cover plate a while back a did not see a distributor gear. By that logic there might not be one on a 98 either...

[arveno]

Thanks everyone for the good info !!

Guzzista , yes i think we should talk swap .

[v65tt]

nice simple solution

https://www.elektronik-sachse.de/shopsystem/index.php?cat=c4_Moto-Guzzi-Digital-Ignition-Systems-for-Moto-Guzzi.html

[John A]

If I remember correctly you have to finish machining the hole to fit the distributor and there is not a gear on the camshaft

[arveno]

If I remember correctly you have to finish machining the hole to fit the distributor and there is not a gear on the camshaft

you are correct.