Slow turning over leads to Crankshaft and sprag clutch issues

I have covered 52500 miles and the Ducati has been pulled apart now. I am in the process of taking the engine out. It started of all things with the bike turning over slowly and not starting as normal.

A few months back, I used to press the starter and the bike would fire up within a couple of turns. Gradually it seemed to get slow in starting and cut out on occasions. Very rare and also if it did cut out it would start again. I did not think too much about the delay in starting as i was searching for what could be causing this. I balanced the injectors which helped the tickover and acceleration. I adjusted the tps, put a new fuel pump. Which turned out to be not the issue. Each time it made a slight difference but not as good as it was before. The bike was getting a lot of use in turning over as it was slow to start, could cut out and needed starting up. It might take a few times to spin before picking up. This all makes sense now as I look back but at the time it was just going out of tune it seemed.

A couple of weeks ago, I took the starter motor of and with the help of Harry diagnosed it was the starter. Putting a meter on the battery and turning it over, there was no drain on the battery. So Harry took off the starter, cleaned it, found the brushes worn and repaired it. Back testing the starter motor off the engine it worked now and very quick.

 

In the video you can see what is taken off to fix the starter. After this video the starter was fitted. It would not turn over and once i cleaned the starter solenoid connections with sand paper it turned over but did not catch the engine. I could hear the starter whirring away but not actually turning the engine over. I phoned Dave Robinson in Wandsworth who is a Ducati specialist. He listened and asked questions as to why I had taken the starter off. Then when I mentioned the engine was not turning over he mentioned the sprag clutch had gone. He also asked me to check the crankshaft. I grabbed on the end of the shaft and felt movement.

So it seems from the bike starting slowly, this has put pressure on the sprag clutch, this has put pressure on the crankshaft and the bike is laid up now. I can remember now that a rumble developed of where the bike would develop this noise between 3 and 4 thousand revs. Looking back now this must be the bearings as they wear. The slow starting putting pressure on the crank via the sprag clutch. It all fits in to place.

 

So I hope that if you own a 916 make sure that if the bike slows down or takes more turns then normal with starting that you catch it early. I hope you get away from serious engine damage. For now I am taking the bike apart and will get the engine repaired.

 

Video of the starter motor removed

 

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