Condor bevel drive 350 rebuild
Posted: Sun Feb 02, 2014 6:16 am
Hello everyone,
I'm new here, not strictly a Ducati owner, but I have a 1976 Condor A350 which at least has a Ducati engine, and as I am currently rebuilding the engine I thought I better sign up here.
For those who don't know, they were built for the Swiss military, with imported Ducati engines. The engine in questioning is a bevel drive 350cc single (spring valve, no desmodromics). I am not entirely sure what changes Condor made to the engines other than re-badging them. An external oil filter has been fitted, I have been told the compression ratio is lower, but the piston, cylinder and head all look normal Ducati to me, so I don't know how this was achieved. As it was all in working order when I got it, I just did routine maintenance on it and rode it all over the place.
Anyway, coming back home one day the engine cut out a couple of times. I sounded just like it was running out of fuel, so I switched to the reserve and carried on to see if I could make it home. A few hundred metres later the engine completely seized and threw me off. I was fine, only going slowly around a muddy country lane, and the bike only has a couple of scratches and a bent footpeg, but the seized engine is of rather more concern. It had plenty of oil in it, and had had an oil change a couple of hundred miles before, with no signs of anything breaking up. As rebuilding a Ducati engine looks like quite a project, I decided to bring it back up to university with me, where I could work on it whenever I get fed up of writing lab reports.
What a student's bedroom should look like
The top half came off without an issue, worryingly in a way, as a new piston / cylinder isn't the end of the world, but a new con-rod comes to over £600 .
Whilst trying to undo the nut retaining the output sprocket, the big end suddenly gave up its grip and the piston poked its head out of the crankcase.
Better that it is no longer seized solid, but the big end is still very grumbly, I am sure it must be the cause of the seizure, although I won't know why it gave up until the cases are split. There is a coating of metal shards all over the insides of the engine, presumably the remains of the big end. The metal shards are also what I assume caused the scoring of the piston;
Anyway, I carried on disassembling it, the flywheel / rotor put up a fight, but with the correct puller it eventually let go.
The stator was the next stubborn part, even with an impact driver one of the retaining screws still refused to come out. In the end I had to grind the head off the screw. Once the stator was off there was no pressure on the remaining thread of the screw so I could just undo it by hand, with no damage to the stator or crankcase. I don't think the swarf from the grinding really matters with all the flakes of ex big end decorating the engine innards, anyway it is all coming apart.
I am just about ready to split the cases now, however the manual I have states that the starter spindle (visible in the bottom right of that image) should be removed, and the starter gear behind it also before the cases are split. I can't find anything retaining the starter spindle. It has about 0.5mm of slack, but I can't pull it any further out, and it doesn't look like there should be any sort of interference fit there so I don't want to start walloping it. Does anyone more familliar with these engines know how to remove this part, or should I try splitting the cases and pull it out from the other side?
Hope this is of some interest to people, let me know if I am going to heavy on the pictures - I find it easier than trying to describe things, but I don't know if it slows the page down for others...
Any advice would be appreciated, I'm more used to mobylette engines (dead simple) or 2CV engines (fix everything with an 11m spanner and a hammer), so the Ducati is a bit different...
Thanks,
George
I'm new here, not strictly a Ducati owner, but I have a 1976 Condor A350 which at least has a Ducati engine, and as I am currently rebuilding the engine I thought I better sign up here.
For those who don't know, they were built for the Swiss military, with imported Ducati engines. The engine in questioning is a bevel drive 350cc single (spring valve, no desmodromics). I am not entirely sure what changes Condor made to the engines other than re-badging them. An external oil filter has been fitted, I have been told the compression ratio is lower, but the piston, cylinder and head all look normal Ducati to me, so I don't know how this was achieved. As it was all in working order when I got it, I just did routine maintenance on it and rode it all over the place.
Anyway, coming back home one day the engine cut out a couple of times. I sounded just like it was running out of fuel, so I switched to the reserve and carried on to see if I could make it home. A few hundred metres later the engine completely seized and threw me off. I was fine, only going slowly around a muddy country lane, and the bike only has a couple of scratches and a bent footpeg, but the seized engine is of rather more concern. It had plenty of oil in it, and had had an oil change a couple of hundred miles before, with no signs of anything breaking up. As rebuilding a Ducati engine looks like quite a project, I decided to bring it back up to university with me, where I could work on it whenever I get fed up of writing lab reports.
What a student's bedroom should look like
The top half came off without an issue, worryingly in a way, as a new piston / cylinder isn't the end of the world, but a new con-rod comes to over £600 .
Whilst trying to undo the nut retaining the output sprocket, the big end suddenly gave up its grip and the piston poked its head out of the crankcase.
Better that it is no longer seized solid, but the big end is still very grumbly, I am sure it must be the cause of the seizure, although I won't know why it gave up until the cases are split. There is a coating of metal shards all over the insides of the engine, presumably the remains of the big end. The metal shards are also what I assume caused the scoring of the piston;
Anyway, I carried on disassembling it, the flywheel / rotor put up a fight, but with the correct puller it eventually let go.
The stator was the next stubborn part, even with an impact driver one of the retaining screws still refused to come out. In the end I had to grind the head off the screw. Once the stator was off there was no pressure on the remaining thread of the screw so I could just undo it by hand, with no damage to the stator or crankcase. I don't think the swarf from the grinding really matters with all the flakes of ex big end decorating the engine innards, anyway it is all coming apart.
I am just about ready to split the cases now, however the manual I have states that the starter spindle (visible in the bottom right of that image) should be removed, and the starter gear behind it also before the cases are split. I can't find anything retaining the starter spindle. It has about 0.5mm of slack, but I can't pull it any further out, and it doesn't look like there should be any sort of interference fit there so I don't want to start walloping it. Does anyone more familliar with these engines know how to remove this part, or should I try splitting the cases and pull it out from the other side?
Hope this is of some interest to people, let me know if I am going to heavy on the pictures - I find it easier than trying to describe things, but I don't know if it slows the page down for others...
Any advice would be appreciated, I'm more used to mobylette engines (dead simple) or 2CV engines (fix everything with an 11m spanner and a hammer), so the Ducati is a bit different...
Thanks,
George