Starting ts410 Fitted new cylinder and piston and carburetter but machine wont start

65 lb compression doesn't sound very much but could be fairly normal on a fairly highly tuned 2-stroke at kickstart speed, especially if the piston, rings and bore are dry.

Exhaust tuning causes a 2-stroke engine to grow in capacity when it is "on the pipe" resulting in a sudden increase in compression ratio and pressure and so if this is not to cause devastating detonation the designer must make allowances and probably utilise electronic automatice timing retard. Starting with a lower compression ratio is another method.
Having said that I would have expected at least 100 psi pressure and probably a little more...

Assuming you checked the new cylinder thoroughly before fitting and ensured all the ports including the transfer ports are open and correctly line up with any ports or recesses in the crankcase and ditto with the base gasket...
Assuming you checked the piston size matched the new cylinder and the piston rings were correctly gapped prior to fitting...

These things should not be taken for granted and should be checked to ensure they are correct. Assuming you did these things and assembled everything correctly (especially getting the piston the right way around) with a smear of clean oil a good induction should be assured and the compression should be almost as good as it is ever going to be.

I suggest you ensure there is a good spark and fuel is reaching the cylinder. If it isn't I suggest you revisit the new parts you fitted and the way you fitted them before investigating anything else.
Good luck!

check that the gasket to the barrel is installed correctly and not upside down blocking of an air hole to the carby
the problem is that the fuel level is excessive causing flooding when the filter is fitted
that is normally from lack of control to the carby diaphragm from blockage or vacuum hole problem
if you have reconditioned the carby , check the way the diaphragm has been fitted in relation to the gasket

Thick white smoke often means something besides gas and air is getting into the cylinders. Possible blown head gasket, holed piston, etc.

Fuel pick up will be your problem. Buy new fuel filter and fuel line from in tank to carby. Most likely a split in the fuel line in-tank

http://www.mediafire.com/download/dk8dipzr69pksrk

I've added the breakdown manual for you, have you replaced the fuel and air filters. could be a simple issue of not being able to draw up the fuel from the tank. Stone saws deal with a lot of dust and this seriously effects their running and also their cooling capabilities.

Starting procedure for Stihl.
(cold starting)

Place cutoff saw on floor (flat clear surface).
Hold throttle in, while pushing on switch all the way down.
Hold cutoff saw firmly.
Pull starter handle until saw fires, it should then cut out.
Click the starter switch up 1 click to half choke.
Pull starter handle again until cutoff saw fires up. note: it will be reving because the trigger is loched on, (blip the throttle once) and it should go to tick over.

There should be np need to keep playing with the choke when the saw is warm. No need to lock the trigger when starting warm..

Power cutters run in a very dusty enviroment, if concrete dust passes the filter and enters the cylinder it will very quicky remove the plating on the cylinder and wear the piston skirt, once into the bearings it will destroy them, if the rings are badly worn ( remove them from the piston and check the end gap by entering them into the cylinder, if the gap is excessive you have had dust entering the cylinder )

It could be seized, or had dust throught the filter wearing the piston and rings, if this is the case it will be a new cylinder and piston required, it is possible to do it yourself if you have a good knowledge of mechanics.

Yes it can be bored, .050 over is fairly common on this bike. Before boring the cylinders, the new pistons should always be matched to the old ones. You always find problems with aftermarket parts. Have the cylinders bored to match the new pistons. Don't bore the cylinders and expect the new pistons to be a perfect match. I hope this helps.

If timing belt was replace due ti timing belt failure, more then likely it has piston to valve damage, this engine is an interference engine, to find out for sure, need to do a cylinder compression test, if any cylinder with zero, bent valves.