125_driver

One other thing I'm looking at is flexi track. The majority of the build up of black gunk on the track which just keeps coming back after a short running session seems to congregate on sections of flexi track. Has anyone else had any issues with it , and is it more likely to cause discharge from the wheels than standard dead straight Hornby track??

That's a good suggestion although I had replaced the decoder it doesn't mean its not a fault with the plug socket etc etc. I have managed to fix one loco simply by re doing a wiring repair I had made previously. For some reason or other having re soldered the wire into place and threaded it through the correct part of the chassis this one loco runs fine again. I'm thinking more and more that it is individual loco faults that are all by coincidence surfacing at the same time as opposed to a fundamental problem with the system.

Yes, there is a sudden accumulation of oil on the track when one of the "unwell" locos are used. But strangely other locos not affected seem not to be too affected by the fresh oil on the track and if anything run a little better due to the very regular track cleaning regime taking place currently! Not had chance to go upto the loft today, but I am very interested in the theory that the loco is getting very hot (for whatever reason) and this is causing the strange performance and perhaps the dumping of oil). Will put it to the test ASAP.

Interesting I hadn't ever even thought that would cause an issue so something else to try. Thanks.

Very plausible as the problem seems to surface after a period of running. The fact some locos are unaffected would surely suggest it is the individual affected locos that are getting too hot. Regarding the bit about low level short circuit, do you mind giving me an example of what could be causing it. I've checked anything obvious but there are things that more experienced modellers than me may have come across that I wouldn't even think of.

I can't imagine that's the issue as It is only controlling the power car and dummy power car. I don't generally run multiple trains all at once. I am using a CT elektronik system.

Yes another poster suggested this and I endeavoured to thoroughly clean the 8 coach mk3 rake I am currently using. Unfortunately it has had no impact on the problem. The fact some locos are working fine and yet others are impacted by this suggests to me the problem must lie with individual locos. Its almost like the affected locos develop a sort of inertia where say the horn is sounded and it either doesn't sound or sounds a few seconds later. Similarly , power can be reduced but the loco will take no notice for say 10nseconds before finally reducing its speed. The locos also need a slightly higher power setting just to keep rolling. What confuses me most is that generally stuttering is associated with dirty wheels track pickups etc yet the stock doesn't stutter at all as you might expect with stock that isn't clean. I've also tried resetting the decoder or even changing it and this has no impact. I'm truly stumped at the moment!

It does get warmer in the summer though frankly compared to the peak of past few summers where it gets much hotter, at the moment this year its never really got hot just slightly warmer than downstairs to be honest.

That's a fair point. Better had try that as well!

I've done this with one loco, but what is strange is how they are all succumbing to this problem all of a sudden. On the loco that I did go into the inner workings etc if anything I found it had less lubrication than I expected. Could lack of lubrication be a cause for this problem???!!!

The layout is in the loft and there isn't really anything I use up here along these lines.

The stock most affected doesn't have traction tyres (Hornby HST TTS power cars). I have done a pretty thorough deep clean of the locos affected , and yet the problem quickly returns (pretty much instantly). From clean wheels to filthy in the space of a minute and visible oil on the track that had just been deep cleaned. Also, I have noticed that when the problem starts, the amps drawn according to the controller start to fluctuate wildly and go quite high, higher than normal , is this likely to be contributing or is this a symptom of the problem I wonder?

Also, maybe a long shot but could this be related to voltage (sudden drop or rises of voltage)???

Sorry I should have also pointed out I have given the track the biggest clean its ever had and it was pretty much good as new afterwards. I hear what you are saying on excess grease on locos but they have all run absolutely fine for 3 years and suddenly are spewing out this oil/grease. I feel like there must be something going on that is prompting this to suddenly start happening after 3 years of excellent running performance.

The above problem began very suddenly a few weeks ago, to summarise, most of the locos on my layout (strangely not all) after a while of running, very suddenly start running very poorly, and specifically stop listening to controller commands (ie Horn or slow down / speed up). Once this has occurred, the problem afflicts said loco like a disease and I notice that after cleaning the wheels which have got very oily, the oil returns almost instantly and dirties up the wheels again and the track straight away. The afflicted locos all have run for over 20 minutes generally before this issue begins, and once affected, as I said I can't seem to cure it. Its a DCC layout if that's relevant. I'm not sure of the dirty wheels are a symptom of what's going wrong or the cause, but to reiterate when affected I am cleaning the wheels very thoroughly, only for the dirt to come back straight away. Can anyone help?

Makes me wonder if I've had a bad batch as a I bought a few sets and all are too small for the power cars. However, all this is no longer relevant as having done a bit of testing in push pull mode for the 8 coach rake, derailment was far too frequent, compared with the original Hornby coupling which from a performance point of view is excellent when being shoved at a scale 125mph. So I've removed the HUnt couplings now anyway. May still try fit them to my mk2 7x coach rake as that doesn't get propelled only pulled .

Trying to fit a set of Hunt magnetic couplings to a full Hornby HST only the ones provided specifically for the power cars do not fit in the coupling pocket ( it is a slightly larger coupling pocket on the Hornby power cars than on the coaches). But the website clearly sells them as couplings for HST power cars, yet they don't fit, or am i being daft and missing something (quite possible). Has anyone else had this problem and come to a resolution? Apologies if posted in wrong area of the forum.

Right thanks for clearing that up.

Nailed it. Thank-you so much. Cv53 was the issue, but strangely it was the opposite if what you suggested. When I reduced cv53 the loco got even slower, so, I thought I'd try increasing it, and hey presto jobs a good un! Thank you so much for pointing me in the right direction and for all the helpful suggestions others made on this post. One final question, would Hornby tts class 47 decoders have cv53?

System is CT electronick. I've generally found most things run very quick on it, and you can modify the power output pretty high if necessary. Id be very surprised if this was the cause tbh. It may just be that what looks scale to me is way out! For the record I'm wanting to run the 37s with regional railways coaches on semi fast passenger duties where they would have reached 90 (or 80???) Mph. I will check the greasing and have a play with cv53 and report back .

It was set to 248, upped it to 255 but no discernible difference. Thanks for the advice though.

Will certainly give that a try thanks .

Exactly. I enjoy my layout running at intercity speeds, it isn't a slow cornish branch by any means.

Its a Howes sound decoder.

I have purchased a couple of Bachmann class 37s and have to say I'm disappointed with the top speed, especially when a decoder is fitted, but even without. It takes one 27 seconds to circumnavigate my layout at full speed, compared to a Hornby TTs 47 which takes 11 or a TTS HST which can do it in 9! Now obviously I'd expect the HST to be faster than the 37, but to me the 37 looks to do a scale 50mph max. I'm after something that will look something like scale top speed (90mph???). Is there anything I can do to speed the locos up, are they setup to be slower than they need be???? Thanks in advance.