Thanks again for your info, I shall try your recommendationsPut some Rislone in the oil. If something is plugged or the pressure valve is sticking it will help. If the oil turns black right away you know the lower end is dirty and is getting cleaned.
Change your mufflers . Plugged exhaust on old barn bikes is common. Run without mufflers at all for a bit just to see what happens.
Raise the needles a notch, once again, just to see what happens.