201 won't start hot

[Westphalian]

Hi, I bought a used MS201 CM a few years back for limbing. It no longer starts when hot. Because the starter rope pulls fairly easily I checked compression which was 150, the cylinder had slight scoring but I am no expert. I took the opportunity of giving it a deep clean and retuned the carb and at home I thought I had sorted it but obviously on site after one tree it wouldn't restart. After a google, people are saying fuel filter, spark plug, vapour lock or ignition module. Can any wise person put the possibilities in order of likelihood so I don't waste too much time and money? 
Thanks

[rusticretreater]

I don't think there is any order of likelihood for these things.  It is more a process of elimination. It might be a combination of things.

You said compression was 1500. Did you mean 150?

These things are usually fuel related.  When they are spark related, usually you get some indication while using the saw.

Start with a deep inspection of the fuel system with a highly critical eye to things.  Pour out the fuel and get a good look at the in tank filter and hoses.

Gauge how well the primer bulb works and compare it to how well it works when the saw is hot.  Heat makes things expand and also get softer.  A fuel line may start to collapse when softer and no fuel is being pulled through it at running pressure.  The primer bulb test might show less fuel getting through.

[DHansen]

What is your hot starting procedure?  Are you putting the saws throttle on high idle no choke position when starting it hot?  Or just pulling it over at base idle speed?  Did you install a carburetor rebuild kit or just clean up the carb?  Have you inspected if the spark plug electrode tip or ground strap is wet when it is a no start situation?

[Westphalian]

I don't think there is any order of likelihood for these things.  It is more a process of elimination. It might be a combination of things.

You said compression was 1500. Did you mean 150?

These things are usually fuel related.  When they are spark related, usually you get some indication while using the saw.

Start with a deep inspection of the fuel system with a highly critical eye to things.  Pour out the fuel and get a good look at the in tank filter and hoses.

Gauge how well the primer bulb works and compare it to how well it works when the saw is hot.  Heat makes things expand and also get softer.  A fuel line may start to collapse when softer and no fuel is being pulled through it at running pressure.  The primer bulb test might show less fuel getting through.

sorry yes, 150, I have edited it. I had a spare spark plug so I will check the fuel system as you say. Thanks

[Westphalian]

What is your hot starting procedure?  Are you putting the saws throttle on high idle no choke position when starting it hot?  Or just pulling it over at base idle speed?  Did you install a carburetor rebuild kit or just clean up the carb?  Have you inspected if the spark plug electrode tip or ground strap is wet when it is a no start situation?

I just put it to "I" and pull the rope. not cleaned the carb just general clean while saw was dismantled looking at manifold and piston. I had a spare plug so just installed that, not tested hot yet.

[DHansen]

The position between the I and full choke is the position I would use on a hot or warm restart of the saw.  You may want to try that and see how it reacts.

[Westphalian]

thanks all seems to be sorted with combo of new plug and a fiddle with L. It started straight away when hot and when lukewarm warm needed to start with throttle open