Richard's ST2 pages - flywheel and clutch

Information on this page last updated 6/9/06.

I replaced my flywheel and clutch basket with aluminum versions from Nichols Manufacturing. The flywheel is part number 16MFLY which works on the early ST2s. Later ST2s and 4s have an updated alternator and a re-designed flywheel. I think this change came in model year 2000. As of 7/00 Nichols did not have a replacement flywheel for the later bikes. If in doubt about whether you have the early alternator or not give Nichols a call and they should be able to tell you. The basket will work on all modern dry-clutch Ducatis and is designed to work with a Barnett clutch pack so that was installed as well. The net reduction in weight is 8 lbs, here are the details:

These modifications really wake up the engine, allowing it to build revs much more quickly than stock. The engine starts quicker, idles about 100 RPM faster, and actually idles smoother. I have not noticed any drawbacks, other than having to be a little more careful with the throttle in order to keep the front wheel on the ground :-)

Here are some photos from the job. Nichols aluminum clutch basket on left, stock steel clutch basket on right:

Nichols aluminum flywheel on left, stock steel flywheel on right:

Left side of engine without and with new Nichols flywheel:

Left side cover:

Tools required for the job are:

• impact wrench (or a long breaker bar, a little luck, and a lot of patience)
• torque wrench capable of 180+ N-m
• 30mm socket for flywheel nut
• 1 1/4 inch (32mm?) socket for clutch drum nut
• 13mm socket for clutch basket bolts
• 3, 4, 5mm allen wrenches
• red loctite
• your favorite flavor of RTV silicone sealant for the engine side cover
• tool for holding clutch basket

The latter are available for $$$ from Ducati, about $20 from Nichols, or can be made with a few tools and some old clutch plates. To make your own, stack several plates (I used 3 friction and 5 metal), clamp together, drill several holes, install bolts through the holes, and attach a lever to the top of the stack either via bolts or welding. This Ducati and Nichols tools will hold just the clutch hub, allowing the clutch drum nut to be torqued. The home-made tool will hold both the clutch drum and the basket, thus immobilizing the crankshaft and allowing the flywheel nut to be torqued as well.

Disassembly/reassembly are fairly straight-forward, but time consuming. For the clutch, the steps are:

1. remove the clutch cover
2. remove the six bolts that hold the clutch springs
3. remove the clutch springs
4. remove the outer pressure plate, some gentle prying may be required as this is attached to a shaft that goes through a couple of seals, all the way through the engine to the clutch slave cylinder in the other side (on some bikes the pressure plate may come off without the shaft, if so the shaft will need to be removed separately)
5. remove the clutch plates
6. hold the clutch drum with the special tool and remove the nut with an impact wrench, if you cannot hold the tool then put the bike in 6th gear and have a helper stand on the rear brake
7. remove the clutch drum
8. remove the clutch basket bolts and remove the clutch basket
9. clean everything well but take care not to let debris into the hole the shaft came out of
10. re-assemble using new components, use red loctite on clutch basket bolts but not on clutch drum nut, torque clutch basket bolts to 32 N-m and clutch drum nut to 181.5 N-m.

I had a problem with the Barnett clutch plates not releasing very well. On my test run I had to actually apply some throttle while stopped to keep the engine from dying and could not shift into neutral with the engine running. I took the clutch plates back out and the friction plates had quite a bit of excess friction material and adhesive both on the tabs and on the outer circumference of the plates. I carefully cleaned up the tabs using a small file, then reassembled and the clutch worked perfectly. I mentioned this to Nichols and they said the quality of the Barnett plates is quite variable and they may add a note on this to their clutch basket instructions. Barnett said that the excess adhesive is a result of their manufacturing process but they do not believe it should cause a problem. The tolerances on the Nichols basket are tighter than stock so perhaps the Barnett plates work fine in a stock basket. In any case, once cleaned up a bit the Barnett plates work beautifully, no slipping or grabbiness.

For the flywheel, the steps are:

1. drain the coolant
2. remove the countershaft sprocket cover
3. remove the clutch slave cylinder
4. remove the three coolant hoses that go into the side cover
5. remove the side cover, it may be necessary here to tap with a plastic mallet and/or re-install one of the clutch slave cylinder bolts and use it as a bearing surface to pry the cover away and break the seal (some oil will drain out so be prepared to catch it in a pan)
6. remove the flywheel nut with an impact wrench, if the engine turns then put the bike in 6th gear and have a helper stand on the rear brake
7. slide the rotor and spacer off of the crank
8. remove the woodruff key
9. slide the flywheel assembly off of the crank
10. remove the flywheel bolts and remove the flywheel from its carrier
11. re-assemble using new flywheel, use red loctite on flywheel bolts and nut, torque to flywheel bolts to 13.5 N-m and flywheel nut to 181.5 N-m, be careful to align the dot on the flywheel assembly with the woodruff slot on the crank and also be careful to align the thin "oil flinger" washer such that it does not foul the bearing between the crank and the starter gear

There is no gasket on the side cover. I used a scotchbrite pad to clean the mating surfaces and then sealed using grey Yamabond sealant (available at Yamaha shops.) You might also use Hylomar or some sort of silicone sealant. Take care to line up the drive shaft for the water pump impeller with the slot in the driving gear while replacing the cover.

Note that for the ST2 the generator rotor only has fins on one side and that side should face outwards on re-assembly. From what I have heard this may be different for other Ducati models. Specifically, I have heard that the 916 manual says to re-assemble the side with "Ducati" cast on it facing inwards. So be careful, and the best bet is to document what everything looks like as you take it off to ensure proper re-assembly.

2006 update - Another fine looking clutch basket is available from Charlie at Procutting. I have not used one but quite a few other ST owners have and I've heard nothing but good feedback.

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