Stihl ms151 not ticking over

[West92]

My Stihl ms151 will not take over. I climb up a tree start it as soon as I press the throttle, it cuts out could this be the time screws any help would be great thanks a lot

[kram]

Each time I've had this on other saws, my air filter has unexpectedly become caked in shite, it can be suprising how quick it can cake up.

 

It may be the idle screw is a bit low but adjusting it could be hiding other issues. Always clean the air filter first.

 

Are you warming it up before you climb?

A full throttle start can get a saw running and I usually start my 2511 like that, as it will start first pull.

 

How old is your fuel? More than a couple weeks, tip it out and a get a fresh mix to rule that out, always helps tho I happily use 3 month old mixes.

 

Next thing to check is a fresh NGK sparky and check the gap as they are rarely the specified 0.5mm that they should be for mine - I dont know if thats the same for a 151.

 

 

 

Edited 19 hours ago by kram

[West92]

Hi kram thank you for your reply my air filter is clean and I go through a can of petrol every couple of days, so I shouldn’t think it will be the fuel so only other two things to check in my opinion is the spark plug and the timing screw if anybody else on here has had this problem please could you share with me how you solved it

[Muddy42]

Id also check for air leaks in the fuel and impulse lines. Blow everything clean and bend the lines to check for leaks. Clean the carb and see if it needs a carb kit.

[Tree monkey 1682]

9 hours ago, West92 said:

Hi kram thank you for your reply my air filter is clean and I go through a can of petrol every couple of days, so I shouldn’t think it will be the fuel so only other two things to check in my opinion is the spark plug and the timing screw if anybody else on here has had this problem please could you share with me how you solved it

The stihl Ms 201t was like that I once owned even though I ran it on aspen, found out it left the factory without a gasket in the carb.

If it gives you no warning and cuts out either  on idle or when your moving around the tree or randomly after a cut . I'd rule out everything else first but that was it .

Tried gaskets and carb rebuild through a dealer no good , tried a new carb through a dealer that was roughly 250/300 from memory .... still didnt run well.

[Muddy42]

A chainsaw that starts and idles OK, but cuts out when revs are applied, normally has a problem with the fuel delivery or throughput of the air and exhaust.  The engine is not getting enough fuel for the increased demand.

 

You say you have checked the air filter, but make sure its not still clogged with fine stuff.  If its plastic it can be washed in hot water.  The cardboard ones need hoovering or blowing out with air.  Or briefly try running the clean saw without it and see if it makes a difference. Check fuel filter.  Again after cleaning the tank out, I will briefly run the saw without the filter to see if that helps. Look for cracked kinked or restricted fuel lines. Look for clogged spark arrestor.  remove carb and clean everything with carb cleaner, remove any dust.  See if the diaphrams are still flexible.

 

I try to do this without replacing parts and setting the carb at default settings.  If you find the issue, replace both filters and tune the carb and the lines if they look old.