]OK......
thank you everyone for your patience, information and suggestions .
I have now had the opportunity to measure all the dimensions of the 3x engines that I have and have finally worked out what the problem is. It is the 200cc barrel or more accurately it is the inaccuracy of the bored and tapped holes for the inlet manifold which on my barrel are about 5mm closer to the engine mount than a cast iron OEM 150 barrel....
As Bristle says....... the LiS crankcase uses the late style engine mount with the long bolt .
The diameter is the same diameter as a standard series 3 mount 70mm except S3 TV and LiS were painted white .
Neither have 3x holes but are listed as 'silent mount' by many sellers
.
GP and later mounts have 3x holes and are also erroneously called 'silent mount' which is a bit confusing as I thought it was the holes that created the cushioning effect .
So my options now are
1. extend the manifold length
2. fit offset cones
3. fit a different carb
4. modify the inlet manifold by welding/brazing
4. fit a different engine
The aluminium barrel is a very crude casting with barely sufficient depth of thread insertion for the inlet and exhaust .
Due to the crude porting there is insufficient material left around the ports to drill the inlet manifold and swivel it to gain sufficient clearance for the carb.
If anyone is considering buying an Indian small block kit all I can say based on my experience is
DON'T
The supplied cylinder head is a standard 175cc head with no clearance for a 200cc piston. The porting on this barrel must have been carried out by a blind man with a grinder , it is appallingly poor and the manifolds barely cover the edge of the ports.
None of the ports have been deburred within the barrel which would wreck a piston in minutes but I guess that would be something you'd need to do on any after-market barrel. Just don't go there