engines

[jward]

in HO or N scale, single powered truck diesels will never pull as well as all wheel drive. that is why the standard is now to have all wheels powered. in addition, the older locomotives with only one power truck were almost always low quality even by the standards when they were new. the drastic improvement over the past 20 years or so in the quality of locomotives has not been kind to these older locomotives. if they were poor quality when new, they are even worse now.
most had 3 pole motors, and minimal gear reduction to slow them down. the result is a locomotive which runs more like a slot car than a real locomotive.

when purchasing used locomotives, especially in HO, here are 4 signs on something i'd steer clear of.

1. on a diesel, a non-powered truck.
2. truck mounted motor with no drive shaft to the other truck.
3. traction tires on any wheels.
4. truck mounted couplers with an open pilot front.

note: number 4 is not necessarily a deal breaker in n scale, as even the higher quality older n scale locos (trix, arnold) had truck mounted couplers.