Chainsaw cutting out

[Paddy_Power]

Hi all,

I have a Proplus chainsaw (Chinese brand). I took it out the other day after not using it for a few months. It fired up and idled but when I started cutting with it it would stall. It has gotten worse and now when it fires up it over revs and cuts out. I have changed the main fuel line to the carburetor as it was perished and cracked and checked the filter at the end of the pipe, I have changed the needle and spring in the carburetor, the diaphragm and gaskets. I have checked the fuel tank vent too which is fine. It has a walbro carburetor/

Any help or suggestions would be greatly appreciated.

All the best
Paddy

 

[Bob Hedgecutter]

Not familiar with the brand- but sounds like an air leak issue.
Pressure and vacuum test to check for leaks arond the engine pan bolting up to the cylinder and main crank seal regions- not sure if it runs a separate impulse line- but that will need checking as well.

 

[Paddy_Power]

Not familiar with the brand- but sounds like an air leak issue.
Pressure and vacuum test to check for leaks arond the engine pan bolting up to the cylinder and main crank seal regions- not sure if it runs a separate impulse line- but that will need checking as well.

I will check for leaks. I have noticed there is pressure in the fuel tank when I open the fuel cap after tried to run, I am not sure if this is normal.

 

[Bob Hedgecutter]

No there should not be a pressure difference between atmospheric and tank internals- so you might also have a blocked/damaged tank vent.

 

[Paddy_Power]

No there should not be a pressure difference between atmospheric and tank internals- so you might also have a blocked/damaged tank vent.

I thought as much. I checked the tank vent and it appears to working as it should. It has a check valve and only lets air in to prevent a vacuum as fuel is used up but it won't relieve a build up of pressure due to the check valve. What could cause a build up of pressure in the tank. Its a relatively new saw, less than two years, with very little hours on it.

 

[Bob Hedgecutter]

Sorry, like I said I am not familiar with the model and how it is assembled.