I'm spending quite a lot of time reworking the previous owners engineering decisions, but where he got it right he saved me a lot of time and effort. I guess it depends on the price. I managed to get my brit, main frames complete and assembled and all castings unmachined and present for £100 on eBay. Had it been £500 I would have been cursing a lot more. As it is I'm quite content.

Maybe buying a part built one that you can inspect fully first is fine, but sight unseen and a large outlay would be a gamble…

I should qualify what I am saying by pointing out I'm a complete novice, so don't take what I say too seriously, just adding my experiences.

I would say yes, but before you condemn the previous builder, understand that you don't know the circumstances. They might have been well-intentioned but incompetent, lack skill or mechanical sympathy or there might be other reasons why the work is poor. My father was trying to complete a Jinty whilst he was on heavy meds for the cancer which eventually killed him. The quality of work was shocking but it wasn't because he was not a capable engineer – after all, he did a lot of work to renovate a 1:1 scale Jinty years before.

I couldn't bear to scrap it so I donated that part-built frame and all the bits to the The Gravesend Model Marine and Engineering Society with the understanding that it would need to be re-worked from the start.

I have 'adopted' three part finished projects and would never condemn the previous builder; you need to accept that he/she was having a go and that is what really mattered, particularly to them. Yes you can end up doing a complete re-make on some of the work but like Brian says you will often get a bargain that is hard to refuse …. that's how I come to have three on the go right now!

I've never bought a used model engine but I do know from long experience that motorcycle repair/restoration can at times involve more time rectifying "work" done by previous owners/mechanics than repairing the ravages of time or normal wear and tear.

The things that some people do are beyond belief. Latest example was a pair of BMW carburettors that someone had attacked the throats with a Dremel grinder where the throttle butterflies seat in the body. Result: two junk carburettors that will never ever idle because of uncontrolled air flow around the butterflies.

Another BMW one that my mate discovered: Previous owner had overtightened a cylinder stud so drilled out and tapped the 12mm stud hole in the crankcase to fit a massive 18mm OD threaded insert — in the process completely blocking off a drilled oil way that connected the oil pump to the crankshaft.

Or:: Cylinder liner not pressed all the way in so the stepped spiggot on the top stood proud of the head gasket surface. Easy fixed, some previous mangler exclaimed, before milling the top of the sleeve down level with the surface. Except when the engine ran and heated up, the sleeve came loose and rattled up and down by the amount that had been milled off the top of the sleeve.

How about roller cam followers and guides installed sideways so they rubbed on the cams and totally destroyed the lobes, the hardened particles going on to destroy the rest of the engine?

No end to the risks of buying something secondhand. But if the price is right, it's worth a punt. I once bought a Featherbed Norton twin for $200 because the previous owner could not get it to run. I cleaned the carbs and turned the float needles right-way up and rode on.

To the late professor Chaddock. I apologize for misspelling your name. (Too late to edit post)

From what I'v read on here, buying new can be just about as big a gamble as second hand.

Ian S C

My dad has a similar story about his Vincent Rapide. A couple of local wide boys were running up and down the dockside trying to bump start it without success, it was on the verge of going into the dock when he got it off them as scrap for a few notes. The valves had been changed but the push rods hadn't been shortened so they weren't getting any compression.

As far as we know, after he passed it on it ended up being fully restored.

Neil