250 wc engine concerns

[asmith411]

I've been away from the forum. My son and I have been working on cleaning up wheels etc., plus the Thanksgiving holiday took some time away.

In the back of my mind I've been thinking of the engine concerns that I have. The engine was last run about 1978. It's been sitting in a damp garage since then.
The engine has been removed from the frame. My son and I removed the head and cylinder. The engine was seized. We found some minor rust on one side of the piston and cylinder. I'm hoping that can be cleaned off with with some wd40 and steel wool and honing won't be needed. The piston dome has a dent in it from the installation of an improper spark plug. The threaded portion was too long. I'm thinking that it is not a major issue, but the forum can make a judgement on that. The valve ports seem okay. Some carbon deposits and a tiny bit of rust. We have been cleaning with a brass wire brush on a drill. The piston dome also.

We have removed the covers on both sides of the engine to expose the clutch housing and the flywheel/generator. We did not remove the cover with the points. I'm not sure how to approach the removal. Maybe we can deal with that on another post.

The generator and the clutch are my concerns now. What condition the generator is in and whether it will function. I'm assuming I will have to pull the flywheel to inspect it and what do I look for?

The clutch I would like to inspect. I'm not sure how to disassemble it. Seems to be a lot of pieces. The blow out doesn't help much. It appears that some lengthy conversation is required to deal with these issues. I'm wondering if phone conversations can be part of a solution. Is there someone out there who can discuss this with me? Let me know if this is possible.

Thanks,
Art

[double diamond]

The clutch can be inspected by simply removing the six spring retaining screws, removing the pressure plate and removing the clutch plates. Alternator removal is a bit more problematic. You’ll need the appropriate flywheel puller tool and an appropriately sized socket to remove the primary nut. You also have to lock the crankshaft somehow so you can loosen the primary nut. If the engine is still in the frame, this can be accomplished by putting the transmission in gear and using the rear brake to prevent the crankshaft from rotating. This method depends upon the clutch being installed , so do this before or after you’ve inspected the clutch. A pneumatic air wrench is the easiest method if you have access to one. This eliminates the need to lock the crankshaft. The tang on the primary nut lock tab washer must be bent away from the nut before you can remove the nut. Once the primary nut has been removed, the primary gear slides off the crankshaft. This gear is keyed to the crankshaft and should take little effort to remove but depending upon the state of your particular engine, you may have to use a 2-jaw puller to remove it. Make a note of the flywheel location relative to the crankshaft, either referencing the notch on the end of the pinion or relative to TDC of the connecting rod. You will need to reinstall the flywheel in the same position. Install the flywheel puller and remove the flywheel. This will expose the alternator coils mounted to an aluminum base plate that is attached to the center case by three cheese head screws. If you decide to remove the baseplate/coil assembly, the wire harness passes through a plastic fitting on the upper center case. This plastic fitting is very delicate and breaks easily. If you see no reason to remove the stator assembly save yourself some grief and leave it in situ. You should also consider inspecting the kickstarter assembly since it’s exposed and this is a weak point of the design. Matt

[ducwiz]

If one is not shure how to remove/dismantle things, it is a good advice to read the fine manuals ;o)

narrow case 250 manual:
http://motoscrubs.com/Ducati_Manuals/4-5-speed-shop.pdf
supplement for wide case model:
http://www.pdfmotomanual.com/index.php?r=site/getdownload&unique=612109d07755a527074ee89853a5f18b
spare parts catalog pt1:
http://www.pdfmotomanual.com/index.php?r=site/getdownload&unique=5acdd9fef52781b975e03ce993359db4
spare parts catalog pt2:
http://www.pdfmotomanual.com/index.php? ... 77bcc83213

Basic testing the alternator can be done without removing it, by electrical measurements (winding resistances, insulation to ground/engine case.

[asmith411]

Thanks, all for your comments.

Art