If the main wash and rinse fills are too low for powerful and continuous water circulation you likley have a fill valve problem [ test by adding an extra gallon of water and see if the circulation sound improves ]. By far the best thing to do is to replace the complete valve, these are still available from WP Pt# 4170000.

Dissembling and cleaning an old valve without replacing the rubber valve seals is usually a waste of time and the only time I would attempt this is if no replacement parts or complete valve is available. When just taking an old valve apart and cleaning and reassembling and cleaning you are playing with a flood if the valve decides to not shut off [ I have even seen these older dual valves flood ]. Cleaning a partially blocked screen will never make any difference [ it just makes us feel good LOL ] as the screens on DW inlet valves are 30 times bigger than necessary for proper water fill, so unless it is totally blocked in a 1/4 inch thick crud a slightly dirty screen will not restrict normal water flow. 

Good Luck, John.

Do can indeed clog, my point is if you can still see most of the SS metal screen when you look into the inlet of the valve taking apart and cleaning it will not help and may do more damage than good. But if the screen area is completely packed with rust, sand, or often bits of plastic from a water hearers disintegrating dip-tube then the material must be removed.

In the field we almost never see clogged screens on DWs and Ice Makers and if these two low water use appliances are having trouble with clogging then every faucet air-rater and shower-head would have had problems many times over and one should be installing a whole house water filter.

I have never seen a bad or clogged flow restrictor and if you remove it on a timed fill machine it will overfill. Yes the overfill pressure switch should prevent a flood, but the overfill pressure on KD16s and KD17s were know for not being always reliable. The KDS17 is already one of the highest water use DWs ever made using almost 20 gallons per full load and the pump out periods were only a minute long so these DWs often had trouble getting all the water out if they were connected to a slightly restrictive air-gap anyway. So if you removed the flow restrictor the machine could consume over 30 gallons per full load, I hope you have cheap and plentiful water and a solar water heater, LOL.

The reason many older inlet valves fill too slowly is the valve diaphragms get a grove set in them and they don't allow enough water to pass through, if you replace these rubber diaphragms the valve will usually work like new.

I don't think there's that much difference in capacity between a series 17 and the series of Hobart KitchenAids that came after that.

The main difference is that series 18 and later had an upper wash arm that provided the ultimate in loading flexibility.  Your capacity issues could be resolved with a KA just one model newer.

Jim, I don't expect you to try and hunt down a viable vintage KitchenAid to replace the one you have, but if you're so inclined, look for KDS-18 through 22 models.  Your stainless door panels from the KDS-17 might fit on those.  Maybe even the 23 series, but that's when KitchenAid dishwashers started turning into Whirlpools.  Someone else here should be able to confirm or correct that information.

You might be able to unload the KDS-17 on craigslist, but if you get no takers and decide to kick it to the curb, save the stainless panels.  I'd be interested in those if you don't think you'll be getting another KA machine that they'll fit on.

I doubt any of the trouble with your 17 is due to hard water issues.  You can't get any better than Hetch Hetchy.  A couple of years ago I bought an In-Sink-Erator clone of a KitchenAid 22 series.  It had spent its life in San Carlos and was in beautiful shape.  I credit Hetch Hetchy water for the lack of scale build-up on any part of the machine.  The pipes in my house are almost 85 years old and very constricted, particularly those serving the kitchen sink.  The dishwasher wasn't filling completely.  I removed the flow restrictor in the fill valve.  The filling process is nearly silent now, and I have the valve on the hot water supply line opened only part way so as to allow a gap of approximately 30 seconds after the tank fills before washing action begins.  Just in case a toilet gets flushed during the fill period.

Ralph

Will not fit any KA DW newer than a 17 series KA DW unless they are flat panels in a trim kit and then they will only fit the Architectural series machines with the 6" high control panels.