Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > 620 engines SS/Monster/Multi are they all the same?

[phil_h]

The only differences are :
early ones are 5 speed boxes.
ignition/engine management units

[Simps]

thanks for the info Phil, much appreciated.

[skidlids]

Apart from the amount of gears already mentioned

the Early ones have a standard type clutch and later ones come with the APTC clutch.
Electronics wise the early ones don't have the neutral feeding into the ECU where as the later ones do as part of the start interlock system.

Although your not stuck with Standard ECU as there are Options
Such as
Standard ECU reprogrammed (setup on a Dyno by either CJS or BSD) and the IMMO removed so you don't need coded clocks or a key, if going this route I would change the TPS for a Linear one

1.5M ECU such as Andy Challis uses, limited to about 8500 rpm by the rev-limiter. Although these can also be reflashed (Direct Link software and key) and the rev limiter moved as per the one on Dallas's bike. As the 750SSie uses the same stoke as the 620 your better off using its ECU than the one off the 900SSie

Another option woulld be the good old 1.6M ECU as used on 748/916/ST2
with a EPROM programmed to suit, as the 748 Shares the same stroke as the 620 I'd go with a 748 chip for the ignition curve

Also after market units such as Nemesis and FIM can also be used

On my spare bike I'm currently looking at using a 998 ECU with the 750SSie Injectors as that ECU knows nothing of coded clocks and runs a normal rev counter, I make it about 11% that I would need to reduce the fuel by using a Power commander

[Imola Duke]

Originally Posted by skidlids

Another option woulld be the good old 1.6M ECU as used on 748/916/ST2
with a EPROM programmed to suit, as the 748 Shares the same stroke as the 620 I'd go with a 748 chip for the ignition curve

This maybe a daft question .....
The 1.6m is for a watercooled engine and uses water temp sensors in the loom.
Do you bypass this ?

[skidlids]

No Steve the Oil temp sensor in the front rocker cover of the 620 does the same job.
to go with the 1.6m ECU You would need the 748/916/ST2 harness, MAP Sensor and Air Temp sensor

[Imola Duke]

Originally Posted by skidlids

No Steve the Oil temp sensor in the front rocker cover of the 620 does the same job.
to go with the 1.6m ECU You would need the 748/916/ST2 harness, MAP Sensor and Air Temp sensor

Thats good news then! i have a st4/2 1.6m ecu and harness complete in my shed!
Ecu has a ducati performance ST4 eprom fitted at the moment.

[skidlids]

The 4.5mm longer stroke of the ST4 may cause ignition timing issues, but then again the EPROM may have a advance curve that works, hard to tell until its tried.
As for fueling which injectors did the ST4 use was it the green ones, if so a Powercommander should easily be able to sort out the air/fuel ratio.
Only other concern is the TPS as the connector is different but the signal should be OK as the Mathesis can test both

[paynep]

620 multistrada motors don't have bearings for the swingarm in the back of the cases so won't work in Monsters/SSs.

Or you could buy my spare cases and swap all the internals over!

6speed boxes and ATPC "slipper" clutches can be fitted to early 5 speed motors

HTH, Paul

[Simps]

Thanks Skidz, you are the DD fountain of knowledge as always!

Originally Posted by paynep

Or you could buy my spare cases and swap all the internals over!

Now that would def be well above my pay grade!!!! Cant imagine what a mess I would make of that.

[skidlids]

I have a complete 620 Engine sat up at Dallas's, think its done 4 meetings since it was refreshed by Baines Racing at the start of this year.
Dallas swapped engines part way through the year in attempt to find his missing horsepower, the engine swap made know difference. Thought about sticking it in my bike to save me refereshing mine but happy to sell it for the right money, I need to check how many gears it has but I think its the 5-speed box