Description
Ducati 900SS 1981
Superb motorcycle in stunning condition
Recent major service work completed including engine overhaul
Supplied read for show or go. Complete with bespoke display carpet (worth £200)
One of the truly great motorcycles of the modern era the Ducati 900SS is a true design classic. This particular was acquired by MIS in early 2025 and has been the subject of much work by inhouse and specialist experts. It needs to be seen to be appreciated. The market at present on all classic bikes is quite depressed and the price reflects this. If you are seriously interested in acquiring a truly classic 900ss thsi bike is worthy of very serious consideration. Delivery can be arranged anywhere in the UK or indeed globally
Work completed August 2025
Performed cylinder leak down test, both cylinders tested in the moderate range
Removed both front discs and machined in lathe to remove all irregularities.
Realigned rear brake calliper as it was binding
Removed cylinder heads and barrels. Found pistons to be on the first oversize. Pistons
and rings gummed up due to lack of use. Cleaned up and check ring gaps once cylinders were honed, all in or very near acceptable limits, reassembled rods and pistons. No appreciable play in main bearings or gudgen pins was detectable.
Found broken fin on vertical barrel that had been repaired with epoxy, removed, and had
it welded
With cylinder heads removed, removed all valves, light grind and lapped valves, all valves guides were good. Replaced oil seals on valve stems.
• All valve clearances on opener and closers rockers were out of spec. The closer shims were split and used hardened washers to a give correct clearance. Set all to . 000”clearance. On the openers , was able to lap all but one to get them with in spec.
Horizontal
Intake opener -. 005
Closer -. 000
Exh. opener -. 006
Closer - . 000
Vertical
Intake opener -. 005
closer -. 000
Exh. opener- . 006
closer - . 000
Replaced one opener shim with used one. 8mm diameter shims from later belt drive 2 valve 900’s are the same.
Honed both cylinders, horizontal had slight pitting that could not be totally removed.
Reassembled engine with new Ducati “O” rings at cylinder bases.
Sonically cleaned both carps after complete disassembly, reassembled and bench synced them
Replaced drive sprocket and neutral indicator switch
Test ran engine, found both cylinder heads were being over oiled. Made two brass restrictors plugs and installed them in the vertical/ horizontal cam support bearing housings.
Although the bike ran on original Bosh electronic system it was replaced with a modern Sachse electronic ignition system with two Dyna coils, new plugs, caps, and plug leads
Repaired left engine case upper brass plug
PARTS REPLACED DURING ENGINE TOP END OVERHAULO
Original speedo was in KPH. It indicated 17, 178 km’s. Replaced it with a NOS mph speedo that indicate 2miles
Hardened steel shims for all closer shims.
One used opener shim
New battery
Oil filter and 20-50 oil
New valve seals
New neutral switch
New drive sprocket
Gaskets as required
Numerous SS. nuts and bolts mainly for bodywork attachments
Brass oil restrictors, one for each cylinder head oil supply made up and installed
New Sachse ignition system c/ w two new Dyna coils, new plug leads, 5k ohm plug caps and Champion spark plugs, L86C’s
BODY WORK COMPELTED
As the bike. Had been modified in its layout and colour scheme the following was done
Added side covers as they had been removed along with mounting frame brackets. Painted, added 900SS decals, clear coated
Rear seat was in poor condition, repaired body work and painted
Petrol tank was usable as supplied
Painted front fender
Repaired, to some degree, fairing and painted with “Desmo “decals, clear coated
SUNDRY NOTES
Chassis electrical wiring harness is in useable condition
Bike has a modified oil feed system to improve oil feed to the crankshaft roller bearings, Feed from the top of the oil filter housing to the left side engine case
Bikes appearance has been modified to replicate that of a 1975 Ducati 750SS. That theme has been maintained in this recommissioning of the bike,
Borrani 04777 spoke rims replaced the original mag rims from 1981
Final result is a superb example of a Ducati 900SS. Suggest retain on trickle charge and handle with care.
MIS
SEPTEMBER 2025
