Turntable on my Jensen JTA-460 is slow. I have replaced the belt and made sure table was lubricated. No change. Can not find a way to adjust speed of table.

SOURCE: Too slow?

http://www.archive.org/details/Turntable_Belt_Installation

above is a generic video that applies to almost all belt driven turntables including yours that will show how to install the belt and a few other things.

this can be caused be a new belt being too wide, you may need a narrower belt.

SOURCE: technics sl-b303

Try this company for help?

service<remove>@turntableneedles.com

they have a help line and may be able to assist you?

Note; take the <remove> bit from the link to email them?

SOURCE: sound wavers (speeds up and slows down)

you need to replace the Pitch controls. I'm presuming it is a sliding pitch control. Use the Red start stop lights that reflect on the rotating wheel. put the pitch in center 0. does one row of the dots on the wheel stay completely still.now just turn it up op down a bit until it starts to move the dots slightly. now watch the dots now while there moving. Do they fluctuate they should be smoothe. do this on both decks to find out which one is fluctuating.

SOURCE: Just received my Jensen JTA-460

There is a speed selector directly under the needle arm.

SOURCE: JVC Turntable model AL A1 BKX , need to know how to adjust speed

I have just fixed this problem on my Aiwa PX3800 with improvisation.
The platter was rotating too slowly, I didn't know how much too slow only that the records sounded wrong.
I imagined the belt, motor and platter as a bicycle gear and so simply increased the gear... I achieved this by winding a thin strip of a electrical insulation tape around the motor head to increase it's radius (like changing up to a larger front cog on a bicycle gear).
I could then time the rotations and remove a layer or two of the tape accordingly until I have achieved a perfect 45rpm. 33 is still way out but I only listen to 45s!
Be sure to trim excess tape from the motor head with a craft knife/scalpel or it'll stick to the platter.
Poor man fix up.