[tangobravo]

While I haven;t opened up the engine on my 900ss ie yet, I am hedging my bets that it is going to require considerable work to get back to a usable condition... the usual ebay trolling has shown that 99-02 900ss engines are rare, but there seems to be a number of 800 engines about, either s2r and 800ss. Physically the engine will fit in the frame, but I am wondering about the electrical system. The 800 had an immobilizer on it, but aside from that, would an 800 engine work with the 900 electronics? A wiring diagram would help, but I can't for the life of me find one online... and a search here was helpful either...

 

[Dukerdr]

When you buy an engine, you don't get any "electrics" with it. A new engine will work with the electrics on your bike, it doesn't care where the spark is coming from as long as it gets there at the proper time.

Maybe someone can verify that the timing sensor on the left side of the engine gets the same signal on an 800 engine as the one on the older 900 engine. I doubt the timing advance is very different between the 2 engines.

The 800 engine is a peppy little piece. The 800 I put in my 620 Multistrada is easily as fast as my older 900 Monster.

 

[duc96cr]

Are there no 1100 engines for sale ? “There’s no replacement for displacement”. Someone in my area has an 1100 SuperSport for sale, so I know it’s doable.

 

[tangobravo]

Oh yeah, there are a few 1100 for sale, but at double the price. I am positive the 1100s would need a completely new harness as well, due to the twin spark setup. I'm still researching what would be needed for the 900 rebuild. If I can get away with just top end work, a 944 kit would be the way to go!

 

[Punch]

A wiring diagram would help, but I can't for the life of me find one online... and a search here was helpful either...

Go here.
Service and maintenance motorcycle | Ducati

There are parts lists that are very helpful.
Also the owners manuals have a wiring diagram on the last page. For the 900SS the owners manuals are multilingual, so if you choose US or UK, it will still be multilingual as in Italian and English.

The 900 uses the 15M ECU and the 800/1000 use the 5XM ECUs.
As Dukedr wrote, the engine simply needs the right signals from whatever ECU.

"Handensco" put a 1000 in a 900 here and it ran using a 15M, but never reported back after I did a modified map.
Also, if you read it, ignore my comments about injector dead time as this was incorrect. The ECU already compensates for that.

https://www.ducati.ms/forums/57-supersport/622873-1000ds-engine-01-ssie.html#post6068865

 

[Dukerdr]

Oh, something I almost forgot. You have a "wide hip" engine. Supersports, Monsters and S2Rs are all wide.

You wouldn't want to use a narrow engine like from a Hypermotard or a Multistrada. You would need to use a spacer on each side of your swingarm, next to the engine block. This would create a weak spot in my opinion. It could be pinned in place or something, but it's just a PITA to consider.

.

 

[tangobravo]

Go here.
Service and maintenance motorcycle | Ducati

There are parts lists that are very helpful.
Also the owners manuals have a wiring diagram on the last page. For the 900SS the owners manuals are multilingual, so if you choose US or UK, it will still be multilingual as in Italian and English.

The 900 uses the 15M ECU and the 800/1000 use the 5XM ECUs.
As Dukedr wrote, the engine simply needs the right signals from whatever ECU.

"Handensco" put a 1000 in a 900 here and it ran using a 15M, but never reported back after I did a modified map.
Also, if you read it, ignore my comments about injector dead time as this was incorrect. The ECU already compensates for that.

https://www.ducati.ms/forums/57-supersport/622873-1000ds-engine-01-ssie.html#post6068865

I must be blind -- I've downloaded every owners manual and parts diagram on that site for 800ss bikes, ever year they were made, and can't find any wiring diagram contained within...?

 

[ducvet]

long and short answer is yes they will fit..... but.

The charging system is the same.
the crank angle sensor/alt cover is likely different. You can swap covers if you make sure you have the correct layshaft gear and set the gap. So using your 900ss parts on the 800 motor gets your ignition and fuel injection to work.

motor mounts may be different, check the motor mount bolt size and either drill your frame to size or sleeve the 800 motor down.

Exhaust, may fit but most small block motors have a shorter head pipe than the 900 so you will likely need a 800ss head pipe.

Throttle bodies/airbox may likewise be different due to the lower heads.

I have done a number of carby 800ss builds and it is pretty straight forward, with the parts you have from your 900 motor and a few ebay parts you should be able to easily make a 800ssie.

That said I would start with a tear down of your 900ss motor as I am a believer in fixing what you have and knowing what you have over buying a unknown motor that could be worse than what you have now. Some times you roll the dice and play ebay gambler but if your 900 engine can be rebuilt you will be better off in the long run to do so IMHO .

 

[tangobravo]

Brad Black from Aus said the same thing -- and I'm not too scared of the engine work... but I was looking at options if the teardown reveals a money pit. I am a bit OCD when it comes to my bike -- even if the case repair was "perfect" it would be niggling at the back of my mind. If things aren't too dire, I could do a 944 kit and a PCIII for the same price as a "looks nice in the ebay pictures" 800ss ie. My last scratch build had me buy 2.5 XT600 engines to get one good one. What are my case options if the 900 one is buggered? Any aircooled SS? (10 vs. 12 mm engine bolts notwithstanding). The specifics are unclear, but some of the real ducati hot rod shops have put aircooled top ends on superbike cases...

 

[ducvet]

Lets start with whats wrong with your 900 engine?

Pictures would help for sure but most anything is possible, it becomes a question of what do you need vs what is a more reasonable route.

Cases are not hard to find but if it is just a cracked motor mount 99% of the time you just fix what you have. If you have broken a timing belt the repair can range from a new belt to a new motor because there are not enough parts left of the old one.

You are simply at the point it is impossible to guess a price because you do not know enough information. tear that thing down and /or give us a better idea of what you are looking at and we can probably give you a more accurate idea of a better direction.

Watch for mission creep as well because when building motors it is easy to have the costs grow for wants that have nothing to do with needs.

 

[Punch]

I must be blind -- I've downloaded every owners manual and parts diagram on that site for 800ss bikes, ever year they were made, and can't find any wiring diagram contained within...?

Sorry - go here https://drive.google.com/drive/folders/0B5V3CDgwlc98enZJekZ2dWxsZUk
and download the service manual required and it has the wiring diagram.

This is a link that is arrived from here. https://www.ducati.ms/forums/241-tech-forum/136183-service-workshop-manuals.html

 

[tangobravo]

Punch -- thanks for the link that's fantastic!