turntables

I will say from 1990 till now I turn the motor on at least twice a month.

I would advice you to find a good Brick and Mortar store and have him set it up for you in your home. Makes a big difference.

Dear @g_nakamoto: Mainly depends on what level of quality performance you want to listen and how many LPs you own.

Pioneer design good, very good and excelent levels of products. Your TT model is not really in any of those levels for today standards, it has really poor measures as specs.
Of course that can works at some limited quality level performance. Its tonearm is not good neither.

You can get an inexpensive Pioneer vintage TT looking at the 600 series, as the PL 630 that's very good motor with good tonearm.

As I said all depends on what you want.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

I bought a PL-71 in 1974 from Radio Shack, when I was attending a university in Cookeville Tn.  Back then, there just weren't many Hi-Fi stores around, unless you went to Nashville, even then maybe a couple.  Audio Systems and Nicholsons.  Anyway, I stopped playing vinyl around 1987 and went to the CD.  About 8-9 years ago, I decided to get my old Pioneer back out and started with replacing the stylus in the original shure V-15.  After trying a few different cartridges, I installed a Koetsu Urishi Black.  It sounded awful until I beefed up the mass of the tonearm.  The difference was like day and night-truly.  I lubed the spindle and cleaned the pots that adjust the speed and the performance of the old Pioneer is very good.  Some can't tell the difference between it and my VPI Scoutmaster.  Proper motor speed, good flawless arcing, sufficient tonearm mass and of course proper cart set-up is all I need.  The main thing I found, was the stock tone arm just didn't have enough mass.  You really have to experience this, to hear the difference and it's amazing what increasing the mass will do, for the sound.  Definitely keep the "51", get a good cart and experiment.  

Dear @handymann : " keep the 51 ".  Depends on what the OP is looking for.

In the other side the 51 and 71 are not similar TT. The 71 had a way better tonearm and I mean by a wide margin and its motor was better too. You can't compare in between and think that in both TTs he will has same quality level performance because it's not that way.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.