there is a reason (or three ) for poor line release when trotting ,bigest is poor alignment of spool within the winding cup creating some astute angles the line has to flow through from leaving the spool too escaping the cowling apature
if the spool is near or at the top of its travel ,the spool is up inside the winding cup .and has too bend over the lip of the spool then exit the spool at a obtuse angle ,then bend around the lip of the winding cup causing friction and excessive rubbing causing jerky flow of line out of the reel.
a under filled spool won't help here ,and if the flow isn't sufficiant this will multiply the effect .
there is how ever a fix ,well a fix that only really works on the abu 500 series that are back wind only ,you see the abu 500 series has a oscillation ratio of 1:1 (one rotation of the handle = one cycle [up ,then down] of the spool cradle {the bit the spool locks into} returning too the same spot every time)
the fix is too synchronize the handle position too spool position of bottom dead centre ,leaving the handle pointing downwards when the spool is at its lowest point of travel .
remove the cowling
whilst holding the handle steady twist the winding cup (clockwise) away from you to release it
twist the spool anti-clockwise to unlock it ,and remove
turn the handle until the spool carrage is at its lowest point ,then grip and hold it there with your other hand.
(at this point your handle will most likley be at a odd angle )
start the dissasemble the handle's fittings (506 its a knobb ,501 a nut and etc) only to the point the handle is loose reposition it pointing directly down (natural position to begin winding from) .re assemble the fittings
refit spool ,winding cup and cowling
now whenever the handle is pointing down (leave in this position after casting) the spool will be fully exposed from the winding cup with less severe angles for the line too travel through .giving a improved free flow of line when trotting.
this fix doesn't work (or not so well) with other models that came later as the oscillation ratio wasn't 1:1 any more ,so synchronizing isn't really possible as the handle never quite reurns too the same place at the end of each turn ,but you should still get good results on the other models (1044,507 goldmax ,704 ,706 ? must check this one )
i set up all my 500 series without backwind and syncronized like this .for faultless trotting