Flywheel / Alternator Tech

[Kato]

Because I've been asked about this a few times recently I thought I'd have a go at writing a bit of guide, there is often talk on this board of engine swaps, mostly people looking to transplant a 900 motor into their 600's, this is not usually a problem if you can find a 900 motor of the correct variety, the 1 question I get asked most often is
"can I use an injection engine with carbs"
The answer is YES, you just need to swap a few parts around, it’s not all that tricky to do, there are a couple of gotcha’s but also advantages the later motors use the 3 phase alternator, much better than the old single phase ones that keep cracking, a little wiring mod will be needed later but it’s not hard to do

Flywheel
PickUps
Case Oil seal for the wires

And thats pretty much it, the first task is to remove the clutch slave cylinder then take off the side case to reveal the flywheel assembly.
http://i142.photobucket.com/albums/r94/kato--/IMG_1231.jpg
Remove the nut from the crankshaft and the flywheel will pull straight off, taking note of the alignment marked by the dot on the flywheel,
http://i142.photobucket.com/albums/r94/kato--/IMG_1247.jpg
Now remove all the allen bolts to separate the alternator case from the flywheel, then flip it over to remove the sprag gear, this can be done by putting back a couple of the allen bolts just loosely on the wrong side and gently tapping them through the sprag will eventually come out, be patient it’s a tight fit.

I’m putting this one back together with a light alloy flywheel from CA Cycleworks, you don’t have to use one of these but it might be cheaper and easier then sourcing the correct part from the dealer, of course the advantage is your engine is going to pick up revs a bit quicker, or you can just swap the parts straight from the smaller engine.
http://i142.photobucket.com/albums/r94/kato--/Fly.jpg
Looking at the two flywheels there isn’t that much difference, I apologise for the crap photo, note the trigger on the alloy one, the main difference here is that the steel one on the left is just over 1lb or for those of you that speak French 534 gms heavier than the alloy one, a not so insignificant saving in rotating mass and in my opinion well worth the effort, when putting the assembly back together there is a little dowel that lines everything up, I only mention this because the last time I asked the question “is that a spare one” pointing to said dowel on the bench the was an eruption of expletives followed by much dismantling, more swearing and a lot of low flying spanners, use the dowel to get the sprag lined up and then with 2 or 3 of the allen bolt evenly pull the sprag into the flywheel, you'll need to take the bolts out after to put the alternator caseing on

http://i142.photobucket.com/albums/r94/kato--/IMG_1255.jpg
So the flywheel assembly is back together and looking like these
http://i142.photobucket.com/albums/r94/kato--/IMG_1249.jpg
It’s time for the most important part of the job............
http://i142.photobucket.com/albums/r94/kato--/IMG_1251.jpg

The two assemblies in the picture are essentially the same, the only difference being the one on the left is fitted with a Corse lightweight alternator, to feed my fetish for all parts not really necessary for a road bike and probably not a good idea if you ride in the dark as they do not push out the power of the standard one, your lights won’t like it, that aside they are fairly easy to source S/H the problem is they never come with this bit http://i142.photobucket.com/albums/r94/kato--/Untitled-1-1.jpg and will never fit without it and of course you cannot buy that part seperately from Ducati:Furious:

[Kato]

If you do deside to go the Corse route and can find the adaptor it fits in here..

http://i142.photobucket.com/albums/r94/kato--/IMG_1266.jpg

Ducati haven’t significantly changed the casting for the for the 2v cases since production started, so that makes life really simple for us in this instance because we need to fit some pickups and even thought not used in the injection motor the casing still has the mounting points.
http://i142.photobucket.com/albums/r94/kato--/Bolts.jpg

Here’s the first of the gotcha’s some of the later casings have the mounting posts but they are not drilled, no great effort to do just a pain as we need them to bolt these on.

http://i142.photobucket.com/albums/r94/kato--/IMG_1300.jpg

The last bit thats going to catch anyone out is here..
http://i142.photobucket.com/albums/r94/kato--/IMG_1233.jpg

The picture is a 2001 900 SSIE it had the blanking plug pictured, again there is a gotcha in that some of the later cases were not drilled at all, it is possible to drill and tap the hole, but you end up with not many threads as the casting is very thin, so I like to machine a top hat thread that and press fit it to the case like this.
http://i142.photobucket.com/albums/r94/kato--/IMG_1246.jpg
Now we can fit the grommet assemble and thread the wires for the pickups, last bit to do before putting the outer case back on is to set the correct air gap should be between .6 and .8mm
http://i142.photobucket.com/albums/r94/kato--/IMG_1252.jpg

Casing back on there is one last job to tidy it up, the injection motor has a pickup sensor poking out the side, I used to just leave it and tuck the wire up out of the way, get some very puzzled looks from people wondering why its there on a carb bike, it's an ugly bit of kit so I now like to make my own replacements
http://i142.photobucket.com/albums/r94/kato--/IMG_1265.jpg
http://i142.photobucket.com/albums/r94/kato--/IMG_1243.jpg

JOB DONE!

[Stafford]

Nice job Rob, have you seen the alternators on the bay? Any good for a track bike? (http://cgi.ebay.co.uk/Ducati-Corse-RS-F0-Race-Alternator-280Watt-/270726122715?pt=UK_Motorcycle_Parts&hash=item3f0888ccdb)

[dr chris]

Great post! Thanks for this. Maybe you can help me ...

I took my alternator off at the weekend not realizing i had to note it's orientation with the crank (duh!). I see you have shown to align the dot to the notch on the end of the crank shaft, but which one it is as there are two? I guess it's the one that lines up with a key way deeper down the crank shaft? Do you know?

Cheers,

Chris.

[Kato]

Nice job Rob, have you seen the alternators on the bay? Any good for a track bike? (http://cgi.ebay.co.uk/Ducati-Corse-RS-F0-Race-Alternator-280Watt-/270726122715?pt=UK_Motorcycle_Parts&hash=item3f0888ccdb)

Stafford thats the ticket mate, just be aware you need to source the casing adaptor I can let you have a drawing to get one made, I've already asked that chap and he does not have them, Ducati only sell them with the full kit at about £400.

[dunlop0_1]

Great write up that very informative.
You might want to add this though. I did this conversion on my spare 620 engine and found out that there are two (at least) sizes of alternator windings/housing. The difference was only 2mm in diameter but the existing 620 windings would not fit into the 900 housing. I had to source some more windings.

http://i139.photobucket.com/albums/q289/dunlop0_1/untitled-6.jpg

[Kato]

Great post! Thanks for this. Maybe you can help me ...

I took my alternator off at the weekend not realizing i had to note it's orientation with the crank (duh!). I see you have shown to align the dot to the notch on the end of the crank shaft, but which one it is as there are two? I guess it's the one that lines up with a key way deeper down the crank shaft? Do you know?

Cheers,

Chris.

Which one do you have?

If its two yellow wires then its the older single phase in which case line the dot up with the woodruff key

If its the later 3 phase (3 yellow wires) look at the end of the crank you'll see it has one short slot and one slightly longer thats goes up onto the shoulder before the threads start, line the dot up with the longer slot.

Hope that helps.....K

[gary tompkins]

Top write up as usual

[900Rebuilder]

Does anyone happen to have a copy of this thread saved with all the pictures still accessible? Just about to get into this part on my build and this post is exactly what I need to talk me through the process :)

[Kato]

I don't even remember writing that :-)

[Kato]

What are you thinking to do ? happy to answer any Q's either post them or PM me

[900Rebuilder]

I've got a 900ie motor to go into my carbed frame (with loom and carbs etc) so need to make the "new" engine work in the old frame. I'll also be using an Ignitech ignition system as well if that helps or matters :)

[Mark64]

I fitted a lightweight flywheel to my s4rt, it made a huge difference in throttle response, I spoke to Nelly from cornerspeed about it, I said it only weighs 250 grams, he said 250 grams isn't a flywheel - it's a pack of butter!

[Luddite]

I fitted a lightweight flywheel to my s4rt, it made a huge difference in throttle response

I fitted a heavier flywheel to my Evo and it made it so much nicer to ride on the road with no noticeable loss of acceleration (perhaps because I lowered the gearing at the same time).

Horses for courses I guess...

[Nasher]

I fitted a lightweight flywheel to my s4rt,

I fitted a heavier flywheel to my Evo

For the sake of completeness, and balanced opinions, I have a standard flywheel in the engine of my M1000.

I've not noticed any difference.

[Luddite]

For the sake of completeness, and balanced opinions, I have a standard flywheel in the engine of my M1000.

I've not noticed any difference.

:chuckle: :chuckle:

[900Rebuilder]

I've got a lightened flywheel for the original carbed engine but I suspect that its not going to work with what I need to do the ie to carb swap

[Dukedesmo]

I'm not sure if it's the case with the 900 engines but are the crankshafts the same as the older carbie?

Asking because, on Desmoquattro engines when they changed from single-phase to 3-phase alternator they used a different crankshaft, such that you can't (easily) retrofit the 3-phase to older bikes as the flywheel assembly won't bolt on.

If this is the case with the 900 then, maybe the carbie flywheel with the pickups won't fit onto the crankshaft?

I have to add, I don't know if this is the case but you'd need to investigate - check the end of the crankshaft, threads, length, keyway etc.

[Mr Gazza]

I've got a 900ie motor to go into my carbed frame (with loom and carbs etc) so need to make the "new" engine work in the old frame. I'll also be using an Ignitech ignition system as well if that helps or matters :)

This seems to be a simple enough question.
Assuming that the new engine already has an alternator, then all you have to do is match it with either a two or three wire Regulator/Rectifier, depending how many Yellow cables come out of the alternator. 900ie should have three.
If you don't have an alternator yet then 3-phase is definitely the way to go.

Not sure how this swerved to flywheel, but standard will work just fine on that.

[900Rebuilder]

The casing is still on the ie engine and the carbed one is completely apart so will be easy to compare the parts when I get into it.

I think what the issue maybe is the combination of ignition pickups / flywheel / crankshaft. The ie engine has the 3 yellow wires and the carbed version has 2 but its the pulse coils that are different as the ie motor has 3 wires where as the carbed version has 4

If the ie coils will power the Ignitech unit ok then that should be much easier or am I missing something really obvious here?

[Dukedesmo]

The casing is still on the ie engine and the carbed one is completely apart so will be easy to compare the parts when I get into it.

I think what the issue maybe is the combination of ignition pickups / flywheel / crankshaft. The ie engine has the 3 yellow wires and the carbed version has 2 but its the pulse coils that are different as the ie motor has 3 wires where as the carbed version has 4

If the ie coils will power the Ignitech unit ok then that should be much easier or am I missing something really obvious here?

The Ignitech powers the coils and picks up it's signal from the 2 pickups in the engine that the flywheel actuates 90 degrees apart.

I don't know but would think the i.e. uses a 'missing tooth' pickup on the gear for reference and then the ECU determines firing points?

If so then you'd (probably) need to fit the carbie style flywheel and pickups for which, pickup mounting points should be there (they are on a 916) but, if the flywheel mounting is different then it might complicate things?

[Nasher]

Do you have the Ignitech already? and so have the instruction manual.
I have it as a pdf if you need it.

You are right in that the Carbie 900 has a 4 wire bundle coming out of the case from the pick-ups, but having looked at the pdf wiring diagram for the Ignatech I fitted to my M900 it appears to only show 3 wires.
The 4 wires go straight to the IC ignitors which are of course replaced by the new unit.

It can't have been that difficult to sort out if I managed it, and I don't remember it being difficult.
It certainly worked.

[Dukedesmo]

Carbie engine showing the 2 pickups under the flywheel, albeit not too clearly;

https://www.ducatiforum.co.uk/data/photos/l/2/2237-1381679455-19151ed87a395a5dea7bdd4a25293d00.jpg

Later injected engine, all be it a 4v so maybe not the same as 900i.e.? showing the 'missing' tooth (actually 2 teeth) setup that a single sensor reads from, there is no pickup on the flywheel as the sensor fits through the outer crankcase and simply 'looks' at the timing gear.

https://www.ducati.org/attachments/img_3525-jpg.86042/

Obviously you can remove the pickup from the 'i.e' type (carbie cover doesn't have the hole in the case) and there should be the mounting holes for the 2 pickup bracket from flywheel assembly. What I don't know is whether the carbie flywheel is interchangeable with i.e. alternator/flywheel as the 3-phase alternator is (in 4v engines anyway) a different setup and the flywheel to crankshaft fitting is different.

There maybe ways round this but it might not be plug and play?

[900Rebuilder]

Looks like I need to get into the ie engine and do some digging.

If not possible I'll have to sell the 900ie engine and put the proceeds towards rebuilding the carby motor which will teach me for buying something without checking first and delay things greatly :(

[Darren69]

You can get heavier flywheels? Lighter is usually to way to go, to improve performance. poor low speed running is usually down to poor (lean) fuelling.

[Mark64]

:chuckle: I love the sense of humour on here :mand:

[900Rebuilder]

Ignitech have come back to me within 24 hours to say that they produce a version of the ignition TCIP4 that accepts the ie pickup coil and will suit my needs for 155 Euro's plus an additional 5 for the reduced harness with the correct female plug on it :)

Glad I took the time to email them now!

[Dukedesmo]

Yes, I am aware that Ignitech make different versions of the unit. I recall, when I was building mine there was a chap I met at SPR's dyno who was building a similar setup to me (air cooled, 944cc) but was using the bottom end from an ST something and I think he had a different Ignitech, designed for use with a single sensor/pick up?

[900Rebuilder]

Yes, I am aware that Ignitech make different versions of the unit. I recall, when I was building mine there was a chap I met at SPR's dyno who was building a similar setup to me (air cooled, 944cc) but was using the bottom end from an ST something and I think he had a different Ignitech, designed for use with a single sensor/pick up?

Yes they have said that this is quite a common request for them and saves me the hassle of getting into the engine too deeply although I'm now torn about fitting a lighter flywheel now I have the cover off ;)

[Darren69]

The single phase bikes like my 748 have a different crank so not straightforward to swap to 3 phase or vice versa. If that helps?

[Dukedesmo]

Yes they have said that this is quite a common request for them and saves me the hassle of getting into the engine too deeply although I'm now torn about fitting a lighter flywheel now I have the cover off ;)

I'd definitely fit a lighter flywheel, in fact I did on both my Ducatis and it certainly livens them up.

Not sure about 900 i.e. engines but whilst the carbie engines need a flywheel as it carries the pickups, some of the early i.e. bikes (again 916 as an example) don't even need the flywheel. It is there simply as a weight bolted to the rotor part of the alternator with the timing coming from the gear, so you can completely remove it.

There is more than enough weight in the crank assembly of any of the Ducati v-twins IMO and especially the older variants.

[900Rebuilder]

Hmmmn not sure I'd be brave enough to try that and I didnt have a big enough or deep enough impact socket so I'm stuck at moment anyways

I can see your point though as I spotted the missing 2 teeth that you mentioned so I can imagine what you describe is entirely possible

[Luddite]

There's an old article by Shazaam on the subject of flywheel weight on Ducati.ms, which is an interesting read.

https://www.ducati.ms/threads/lightweight-flywheel-pros-and-cons.29734/

[Mark64]

Lighter flywheel = spin up faster and slow down faster, the engine braking effect is mega, like weighing anchor!