I have no clue on the angle. Just go 9 inches from top of axle to top of seat. 23 inches from front of seat to front of frame and 2cm below the frame rails. This should get you started and you can fine tune from there.
Mine a little over 8.5″, but you may also need to move it further forward if you are adding any weight to the back of the seat. If it has a flat spot on the bottom of the seat, make it parallel with the frame rails. This should give you a good angle to start with. What model and year may also have an effect on where the seat is placed. Mine is a 2008 CRG KT11
Could someone tell me please what is the different between the nylon washers an the rubber ones you put on the sides of the seat to mount an how thick they have to be I don’t want to start bending the brackets. Thank Yous.
The nylon will mount the seat a little more rigid than actual rubber. They both help reduce vibration from the engine. Mounting it solid with only steel washers can make the driver feel w lot of vibration. I’ve done this with a yamaha and it almost takes your breath away from the vibration. You can use as many washers as necessary but ideally you should have less than an inch of washers on the sides. The bottom on many karts regularly takes aa much as 2″