I recently purchased a photo 2000 GP7 on eBay and I'm curious if anyone has had a problem with theirs running really sluggish? I have other Proto 2000 locomotives (mostly SD7's and 9's) that are fantastic runners, quiet, excellent low speed operation etc. Ive never had a Proto GP unit before but this one is a dog. it was analog when I purchased it and it didn't run that great on DC. I converted it to DCC and it didn't really run any better, the problem being that I have to get it to about speed step 40 before it will start moving. I noticed that one of the flywheels was rubbing against the counterweight, so I adjusted the flywheel location and trimmed some from the counterweight so it wouldn't rub... no noticeable change in performance. I removed and inspected all of the drive gears looking for cracks or breaks, cleaned and lubed them, put it back together, no dice, still was sluggish. next I replaced the motor with a motor from a spare SD unit that I use for parts and it still has issues. Next I tested it with a different DCC decoder, you guessed it, still the same problem which is really confusing seeing as I have basically replaced or inspected and cleaned the entire drive train and electronics. I've started thinking about giving up on it as a lemon and getting another one but I don't want to spend the money if this is a chronic problem for the Proto 2000' GP's. If anyone has had a similar experience or if you just have an idea of something I've missed or that I may want to try I'd be interested in hearing them. thanks, -Paul
Heard on one site awhile back that life like early walthers proto had different gear ratios almost unit to unit. Also heard that some get funky with the boards. Just my thoughts opinions.
Thats the other thing, the decoder I used is a PNP so I removed the factory board... its just weird. I may look into the gear thing though, I believe I have heard before that they are clones of athearn bb's and it looks like it, I've thought about finding some athearn replacement gears in case there was some damage that I may have missed.
I have 4 GP7's and 9's (Proto 2000's) I purchased 12 years ago from the C&O Historical society, lettered for Phase I issue of each to the C&O. They look really good. One has a real running "issue". There is one truck (cab end) that seems to bind and runs, as you say, sluggish. The other 3 have run fine. Funny thing was, it ran great for about a year and then just started its shenannigans w/ the jumping and sluggishness. I pulled it apart way back when and cleaned the gears, check everything, but could never figure out what was causing this. With all the other layout chores and stuff to do, I put it away and it is still in the box. I got frustrated with it and moved on. At some point and especially after thinking about it due to your post, I may have to pull that sucker out and give it another go. The bottom line is, check the gearing and drive train to the trucks. There's something there w/ mine, just never was able to put my finger on it. Good luck!!!
The gears when they crack can have the smallest crack but under load the crack widens just enough to cause grief.
I actually just pulled the axles out again today cleaned them off and looked at them under my magnifying lamp and could not see any cracks. I tried turning the wheel sets also to see if they would spin free and they seem tight.
Its just really weird and frustrating. I'm pretty mechanically inclined and am usually good at figuring problems out but this has me stumped.
Try replacing the wheel sets (wheels, gears and axles) I've fixed slow and lumpy running on my Proto 2000 locomotives by dong that.
have multiple Proto GPs that run fine, it is not an inherent problem, seems you have a TLC candidate. if it don't run on DC, it won't run any better on DCC! and you are better fault finding and curing running issues as DC, only once you have it running spot on put a decoder in it. Most likely a gear problem but definitely a "mechanical" issue. yes the gears are the same as Athearn BB units. I recommend replacing all 4 together so you know they are all the same ratios. check the top worms, make sure nobody has replaced something that isn't the same.
UPDATE!!! I had mentioned earlier that I had tried a couple of different decoders with no change in performance, well... I have been over this loco a half dozen times, I was positive it was not cracked gears. I took out the motor and bench tested it again with a different decoder and it ran like a champ, that made me think it was a decoder issue. The decoders that I had used were some older non sound ones that I had removed from other loco's and just kept on hand for temporary use so I changed it again with a brand new soundtraxx econami sound decoder and it solved the problem. I cant explain why the other decoders hadn't worked (I don't know if they just get worn out) but this one did the trick. I now have an excellent running PK2 GP7. Thank you all for your help and suggestions, That kind of help and support sharing your knowledge and experience from the community is priceless, thank you all again. -Paul
