OK, where were we? That's right, The Pup, and The Corporal, were 'Done', or so I thought........... and I was pressing on, looking to do the Black-One as my 'next' project; to which end, the first thing to do was to sort out that dead engine.
So, time to get busy, and the engine was pulled out to be stripped down for a look-see.
Learning from experience doing the first one, the inlets were plugged with corks, rather than rags, and the cam-caps diligently marked up so I'd know which way round to re-fit them!
A bit of welding rod was attached to the cam-chain to save silly questions and much fiddling later, and Donna was let loose with a rubber hammer to tap the barrels from the base gasket.
Inside, was much as expected. The cause of failure was 'gummed' piston rings, leading to poor bore lubrication & premature bore wear. Looks like common 'lay-up' problem, and fits with the sellers comment that the bike had been sat in his uncle's garage for many years unused, until he decided to do his motorbike tests, and he basically did an oil change and started using it! With the gummed rings, it would have run, but not giving proper compression, which would have got worse and worse as the bore suffered accelerated wear. This sort of explains why in the receipts that came with the bike, it had been in for anomalous running problems that had resulted in the carburettors being fully reconditioned, and then almost the entire ignition system replaced, before compression testing identified the real problem!
Cylinder head was in fair shape, though sooty and with the valves out, the seats were a bit pitted, which wouldn't have helped the compression. So, conclusion was, a top end rebuild ought to sort it out, and another barrel kit was ordered, as for the Corporal.
Conveniently I have done this before, and written it up as HOW To: (Honda CB/CD/CM 125/200 'Benley' Series Engine) Top end Rebuild, so if you want to look at gory guts of Benley engine, that's where to look, and I need not repeat it all here!
However, THIS was about as far as it got. 23rd May, a week under a year from starting it, the Pup passed its MoT.
Two weeks later, on the 4th June, Donna was aboard, using it to complete her CBT, and the very next day, we decided to celebrate by riding The Pup & the Corporal to Leicester to show the Pup to her Mum.
Except THIS happened!
The Corporal, decided to snap its cam-chain! HINT... if the cam is easy to time in..... the chains probably stretched beyond use! SO! The engine for 'The Black-One' was bagged and boxed and put on a shelf, so I could tear into the Corpral's engine.... again! Actually, plural, engineS! After trying for a week to retrieve all the broken bits of cam-chain from the crank-case with a magnet on a stick; and pondering how to loop a new cam-chain on the crank, I ended up deciding that my best bet was to strip the engine that had come out of the Corporal, that had a seized crank, and rebuild that with the salvageable bits from the one that had just gone 'pop'. This meant THREE engines all in bits at the same time! However.... eventually.....
Now, remember Donna's Pup had not had an engine rebuild. She planned one to learn about engines; but her bike was bought, supposedly, as a recent MOT fail, and a runner. So we didn't anticipate any major problems using the engine 'as was', and doing a rebuild to teach her engines on another that she could slot in later. Maybe building a 'big-bore' engine for after she passed tests.....
Yeah... That's right, I said, The Pup, and The Corporal, were 'Done', or so I thought. Well, the Corpral, proved it wasn't finished with me, and..... 5th July, Donna was on her way to Rider-Training for Mod 1 practice, he test booked for the following morning....... yup, her engine went 'pop' too!
I had 'just' finished the rebuild on the engine for 'The Black-One', and was all set to put it back in the frame and set about fettling the bike up for MOT.... but some-how, it disappeared! Yes, ALL of it!
Donna had 'Borrowed' the engine. But to hide the evidence, she had decided to 'Help' me by stripping down the rolling chassis..... and HIDING all the bits in the caravan, hoping I wouldn't notice! So I had to wait for her to pass all her tests, AND find her another engine, before I could finish this project!
Part 4 - Putting it together.... Finally!