Husqvarna 265 RX - Vapour Lock ??

[ecovandal]

Hi,  I've got a load of 265RX Husqvarna clearing saws.  I know their old 'skool' but they do the job for me.  We use them a lot in the clearance of decent sized scrub.  The problem is , is that they are all becoming increasingly more difficult to re-start after running.  I've changed carb diaphragms, cleaned filters, plugs etc but they all seem to have some difficulty in re -starting which is becoming increasingly frustrating.  I'm assuming vapour lock but was wondering if anyone had similar issues and any resolving solutions ( I buy the more premium petrol )

 

Many Thanks 

 

Gary

[Muddy42]

You say the machines are hard to start when warm.  Are you sure its pure vapour lock (fuel boiling in the lines/carb) rather than fuel delivery issues?  Does loosening the fuel cap help?  Is the fuel tank vent clear?

[Stubby]

Or it could be low comp especially on a machiene well used and that old . Once it heats up clearances open up to the point its not enough to support combustion .

[spudulike]

As Stubby said, it may just be that the engine is lacking compression. It is worth doing a compression check...anything over 150psi cold is OK and over 145psi warm is sort of OK. 175psi cold would be much nicer.

If low, fit a new piston if you can get a new OEM part or decent aftermarket one.

[adw]

Just to add if you think this is vapour lock, get the heat out of them by cutting some windows out in the top cover, this always helps especially as the covers well enclose the cylinder, do it opposite side of the flywheel to allow air flow over the cylinder.