Most Mosquito sailors find it quite hard to get the mainsail up. The reason for this is that the modern sails are cut very full so as to allow a lot of adjustment while sailing. Add to this the full length battens and you have a sail that really does not want to go up the mast.
The degree of difficulty varies a bit from one boat to the next and one sail to the next, but no-one should need to resort. to turning the boat on it’s side!
The halyard pulley at the top of the mast does not need roller bearings and “10c piece” size should be enough (though bigger would not do any harm).
The halyard is not normally run through the mast. They usually run down the bolt-rope track. The pulley at the top can be a simple one riveted to the back of the mast with the track cut away. A typical Ronstan version looks like this from the top:
| | +------- ) ( +------- | |
One thing which can make it very hard to get the sail up is a pulley at the base of the mast. People have these so that they can pull upwards or get the crew to pull from the back of the boat. They make the job a lot harder. It’s best to have the halyard come out of the track at the same slot (cutaway) where the sail goes in. This way you can use all your weight to pull down on this end (with sailing gloves on). You can also wrap the end around your foot and stand on it if you need to.
It also helps a lot to push the battens up the track as you pull down on the halyard.
Don’t use a thin halyard. 4mm would be the minimum.
If you’ve already tried all this and still can’t get it to go, maybe you just have the batten ends very close to the bolt rope (in which case you can unscrew them and relocate them a bit further from the luff).
Another possibility is that you have a very thick bolt rope (or thick material around it). In this case you may have to resort to spraying the track with silicon spray (like CRC). This works well, but it’s the last resort because in time you will find that you will get a black mark from the mast along your bolt rope (from the aluminium), which doesn’t look very nice.