Me again....just been digging for more info....you do indeed have the restricted jet needles.to confirm this there should also be a metal plate beneath the diaphram, fits over the flat part of the slider....to regain full power you need to fit the correct needle ,5D86, remove the metal plate and also fit the correct spring, the one you have will be a bit stiffer....might be worth posting a wanted ad in the for sale section to see if anyone has the parts.......