Hi, im having problems with the jib on my 420. Every time we go on a beat the jib starts vibrating and it backs even when all the other boats are pointing so much further. Im not too sure whats causing it, ive tried most things now and still havent found the cause.

Anyone have any ideas?

I think you are asking the impossible here

A little more info such as  what kind of vibration, whole sail, luff only, age of sail, rake, rig tension etc may help the knowledgable cast thier wisdom

Trying to point high can often be the cause of not pointing. Often the boat needs a bit of speed to get the foils working properly. Once you're up to speed you might find the height will suddenly come along!

420s don't point very high. Should sail with the inside tell tale lifting. Definitely below the average angle of a handicap fleet.

The whole set up of the boat, from mast rake to board position has to be though about if its a problem in a 420fleet though. Jib trim is quite crucial. Barber hauler in some conditions makes massive differences, there are quite a lot of various tuning guides around on the web. It does depend a lot on the sail, if its vibrating it sounds old, and a new less stretched sail will point higher. Letting off the jib cunningham flattens the entry which may help. Lowering the jib on the luff wire will allow you to sheet harder without having too closed a leech.

Its a kind of annoying vibration just on the luff of the sail,  the sail is about 2 - 3 years old, we dont often alter the shrouds so could it be their too tight or lose?

That more of a help?

Agree with the other posts. The best way to go high is to drive low and get enough speed to make the foils do their thing. Pinching rarely works as the boards stall and the boat slips to leeward despite the bow pointing in the right direction. Oh and keep her dead flat. Are your foils in decent condition or has the lake monster been taking nibbles?

But if you haven't adjusted the shrouds for a while maybe now's the time to do it. Check that your settings are on a par with faster 420s. Also check the position of the jib fairleads.

The foils are spotless, never had a crash except once when the crew messed up the jib sheets. Yeah theres a few 420s at the club one went to worlds so ill compare the theirs for the shroud position. Its not that we're pointing too high, we'er on more of close reaches than beats, we are basically going across the lake while the rest are going up. It also only seems to happen on port so that may suggest to me that we're being stupid and the shoud position is different on one of the sides making the mast bend to that side, would that effect it?

I would check the rig settings before you do anything else, bat speed is key to get foils working pointing to high to early i find almost stalls boats but i ont sail a 420, is the jib sheeted corrctly it is possible to over sheet, reading more of your later post suggest spreaders are different on each side or the mast is bent!