Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Hi Richard,

Though I am fairly competent at repairing things my knowledge of Mamod components is limited. Most of my '0' ring conversions have been on Mamod locomotives, to be able an 'O' ring to work well the bore of the cylinder has to accurate to size, too big and the ring falls through, too small they don't work as well and wear quickly. I have repaired Mamod cylinders similar or maybe the same as the one on your roller, a lot of the problem I found was the reversing gear and the steam ports not lining up very well, so the engine works better in one direction than the other: because the cylinder is moved for reversing, the port faces don't necessarily marry well in both positions. Most of the time I have found that it is a combination of elements that effect how well the way an engine runs. Fitting an 'O' ring might help but it too tight the engine probably won't run as well as it does now. I don't make spares, but if you could send me the engine complete I could see what could be done. This would mean un soldering it from the boiler and drilling out the 'pop' rivets that hold the engine to the fire box.

I am away from the UK until the end of the month.

Take care Tony.