Just been playing with my Merlin and I noticed when i rake the rig aft, im loosing shroud tension, is this correct of is ther something not quite right with the one-string system?

Anyone with any ideas where to start looking or is this normal and you just have to pull some more shroud tension as you rake?

That is not right at all. What boat do you have? If it is a standard Winder one String system you should find a block aft of the king post which has your shrouds, lowers, kicker, puller and forstay all attached. Make sure your shrouds are still attached and if they are trace the rope back to shrouds. Somewhere along that line you should find a break otherwise they would be working.

If it is not a standard Winder System I suggest you speak to whoever fitted it.

Before saying it is not right, we need to know your sail number! Anything pre 3630-ish, and what you are describing is absolutely standard, and the routine for raking is jib halyard off, shrouds on, lowers on, kicker on, jib sheet on, mainsheet on, centreboard up.

For removing rake, reverse the above, otherwise you close down the leeches bar tight and stop moving forwards!

If you do have a one string arrangement, you would expect that the shrouds would keep tension so there could be somehting amiss..

GGGG

This is true, my comment is assuming that you do actually have a one string system.

Dear Newbie, you might have attracted more help from we ever-helpful Merlin Rocketeers if you had not entitled your thread "Help?!" - too vague! 
It may help you sort out your strings if you cast an eye over the diagrams shown on the 'Technical Drawings' page of my website - link below.
Happy threading!

If you need any more help why don't you say where you are and I'm sure that there will be someone nearby who would be willing to help by meeting up and having a look over your settings and explaining them.