Ok here is what I found out so far:

This was done in DC voltage

Start voltage is [email protected] forward and 2.7v @ .11a backwards
7 volts .13a forward and .15 backwards
10 volts .17 forward and .18 backwards
Full [email protected] and backwards .2a
After 5 laps (41.5 feet per lap) [email protected] forward and [email protected] backwards

No load on track 15.2volts

Stall wheels spinning [email protected]

Time after 1 lap 33sec at 41.5 feet =75 mph

Time after 5 laps 30sec at 41.5 feet =82mph

My meters are fluke 88 and fluke 87. Time was with stopwatch, power supply Athearn 16v dc out

Total time on engine about 45 min.

Engine is a Bachmann Spectrum EMD SD45 82715

Is this is good as it gets with this engine?

Thanks for all your help and input guys

Henry

Well after checking time and distance I get 95mph on one and 78mph on the other. Track voltage is 18v. I can rig up dc on one of my loops and will run them for awhile and see if that does any good on the slower one.

WGL: great link this is simple for the simple man like me

Thanks Henry

Thanks Bob I will get a draw meter and check and see what I get. I have some gp38 engines that do real good as far as pulling. I just got 2 spectrum sd45 and one runs ok I guess but the other is a DOG.(I am running a 5 amp power supply on 18v) I have run both for 30 min. about 10 min forward and the reverse and then forward again and I have not seen much improvement. One will catch the other in about 8 laps (about 55') I have check lube in both axles as well as the gear. Now I have also just got a sd45 athearn now that one is awesome but these Bachmann run slow but look great.

How do you check scale speed for HO? 

Thanks Henry

Dave I have the same problem I have 2 new SD45 loco that do not run well at all. I hope someone can help Henry