|You want your tramp very tight, but not so tight as to break the boat. By tightening the tramp it helps to stiffen up the boat.
On new boats I have used my main blocks to "winch" the side bars together, then tighten the tramp using pliers and a lot of force, and then let the blocks go.
But your boat isn't new so I would go easy on it and not go all out first time. Force some bend, then tighten the tramp and see how it feels. If it needs more tension then do it gradually. Just remember it is possible to break the boat if you go too nuts.
Hope this helps