What it was I brought it last Friday as a non runner the guy said he was out on it and it just cut out on him so I done a compression test on both cylinders and they were 143psi each and there was brilliant sparks on both plugs so I new it was fuel or timing related so I took a chance and brought it for £320 so when I got it back I stripped the carb and cleaned it as the vacuum pump wasn't doing its job so thought that was my problem so rebuilt it and tried it and I was getting it to fire but that was all so I then stripped the inlet manifold and found that the rotary valve was in 2 pieces so I put a new on it yesterday and it fired straight up but want revving but after finding a bit more info today I've now got the low rev screw out as you say and the high Rev screw as you say and it'snow starting and revving like it should so hopefully all is resolved now, it doesn't quite start instantly but all is good now I think !
Also I set the rotary valve 130 degrees back from the the bottom of the inlet closest to the front of the ski with the piston closest to the front of the ski at top dead centre. I believe this is right ?! I googled it ! Which isn't always correct. And as for the rotary valve breaking in to 2 I'm not 100% as to what did cause it but the 4 bolts that bolt the inlet to the block 1 of them was missing which was causing the manifold to splay from the block and as for the other bolts they were all loose and the the female side of the threads not great at all so I tapped all new threads in to them this morning and fitted with new bolts.
