Newbie to the board. Replaced filters. Moto jet started strong then lost almost all flow. Main diverter valve is hard to turn under pressure. The owners manual says no reason to replace except hard to turn. Is there anything else that could block the flow? All other jets flow strong.

On our D1 spa both my diverter valves are hard to turn under pressure and have been like that since new.

You want to see if air is coming out of jet. If not it could be a broken airline - very easy fix.
Make sure the diverter lever is pointing left or right. Make sure the air control is open.
What model and year HotSpring spa do you have? A serial number is best.

Pete

http://www.makesmeshutter.com
http://www.floridahotspring.com

No air, Pete, and not very much water! It's a '96 jetsetter serial # JQ361021.
Thanks for replying.
Tom

Lets see.

Pull the filters first. Again, make sure diverter valve is in correct position. Make sure air control is wide open.
Then I would remove the jet - pull off airline from nipple, see if broken. Unscrew jet by reaching in to where it is threaded. Inspect the hose inside the ribs and see if split. Hold the jet by the threads and let it hang - it should hang pretty straight - if it has a curve replace the jet.

Hope this helps

Pete
http://www.makesmeshutter.com
http://www.floridahotspring.com