Back in the days it was known that the Kato Unitrack #4 turnouts are not reliable and it was advised to go with the #6 turnouts (with which I never had any problems). Fast forward few years (me working with the O gauge in the meantime) is this still the case? I see there is also a Compact Electric Turnout (20-240) with 6" radius. This compact turnout is part of the layout I am looking to build but I am wondering if I should rework the track to use #6 turnouts.
In my opinion, if you have the space, I'd use #6s on the mainline. The Double Crossover 20-210 uses four #6s and is a safe bet too. I'm not sure if anyone knows for sure, but some users believe that Kato has improved #4 reliability. I bought a #4 perhaps three years ago and it was awful. I recently bought four #4s, with one a troublemaker and three excellent. The location of the #4 troublemaker might have been its undoing. I notched one of its stock rails and it's been good since. The other #4s required no reworking. Unless you're running tiny equipment like two-axle locomotives or trams, I suggest you stay away from switches with a 6" radius. You ask good questions and you'll receive a lot of wisdom here I suspect.
For the harbor area I am using the 20-240) with 6" radius. My very small 4 axle locos have no problem with it and by small I mean the 44 tonners and smaller. Up on the mainline it is all number 6 Katos. Tried a couple of number 4s and they gave so much trouble that they were replaced.
I recently bought two #4 (left and right) for testing. I created a thread about it here. Anyway, it's entirely dependent on the locomotives as far as I can see, whether or not you will get issues. Notching the rail helps a lot though.
Thanks. I will rework the layout to use #6 turnout. I will run only small locos (switchers) on the layout but looks like #4 turnouts can be a hit or miss.
