Stihl MS181, Hard to pull cord,wont start.

[mickyblueeyes]

4 hours ago, bmp01 said:

Micky,

It probably would be quicker/easier to get some one to look at it for you.  But before you do a couple of quick things to put to bed:

-Post a picture of the piston as seen through the exhaust port (now you've got exhaust off).

-Really make sure you've got the chain brake disengaged. 

-Pull the clutch drum off  ( its the thing the drive sprocket is joined to,  held on with the 'E' clip) and the bearing inside. You need the chain brake disengaged to do this as the brake band will grip the outside of the clutch drum. Do NOT attempt start the saw like this (ignition off please while you pull the cord) we're just trying to find out if the clutch was making the saw hard to turn over. 

 

Maybe there will be a clue in here.

 

By the way, not every MS181 has the Stihl easy start mech,  but it's a small displacement saw that should pull over pretty easy anyway. 

 

bmp01

 

 

Will get some pictures up on here as soon as,and will look at getting the Clutch drum off,to be honest one thing i noticed after having removed the muffler and turning the flywheel was a loud sucking noise like a carp rising up for a dog biscuit for any fishermen reading this,seems to be a lot of compression going on here. 

[spudulike]

If the saw will spin over freely with no plug in then there are no mechanical issues so checking clutches, flywheels etc is pointless if the issue only happens when the plug is in and doesn't when the plug is out. The only thing the plug is doing is sealing the cylinder combustion chamber.

Either the plug is too long and is acting as a piston stop or there is fluid in the engine or thick oil in the bore making far too much compression.

 

[mickyblueeyes]

3 hours ago, bmp01 said:

If you read the first post through he says it was hard pull over and that's why he put some thin oil down the plug hole. .... it subsequently loosened up (or he just got used to pulling it over). 

 

Maybe the O.P. can confirm that's true AND if the brake was on or off and if the ignition module had been gapped correctly at that stage. 

Actually just take the 5odding ignition module off, take the clutch off, and show us a picture of the piston through the exhaust port.......

 

bmp01

 

The oil was added three weeks ago after that i just left it but now i really need the saw for the logs.

 

As for the brake ,i tried pulling it over with both on and off situations.

 

The ignition module was gapped using a business card but that isn't the issue as it's getting a spark.

[spudulike]

Just now, mickyblueeyes said:

Will get some pictures up on here as soon as,and will look at getting the Clutch drum off,to be honest one thing i noticed after having removed the muffler and turning the flywheel was a loud sucking noise like a carp rising up for a dog biscuit for any fishermen reading this,seems to be a lot of compression going on here. 

That is all the FLUID in the machine, it needs drying out so take the muffler off, take the plug out and pull the little bugger over in all positions - upright, on its sides, vertical etc and pull it over hard. Put the plug back and pull it over softly and see if it will spin.

 

Next we can start on how to get a flooded oily saw started!

[mickyblueeyes]

2 hours ago, spudulike said:

You sure it isn't a 181SE - now they are a bit brutish to pull over.

A little girlie can pull these saws over, if it spins over with the plug out but not with it in then it has to be some sort of hydro lock in the bottom or top end of the saw unless the plug is too long....this could run and run

It's a MS181 C Iis what it says on the box anyway.

[spudulike]

The 181SE is an old school 80cc Husqvarna with no decomp - they are a bit tasty when pulling over!

[mickyblueeyes]

3 minutes ago, spudulike said:

The 181SE is an old school 80cc Husqvarna with no decomp - they are a bit tasty when pulling over!

It's a MS181c Spud.

[mickyblueeyes]

Thanks for all replies,i will report back when i have done some of the things suggested and taken some pics.

[Steven P]

Reading this, spark plug out  amd the saw turns over mostly OK. Spark plug in and it won't turn over. So ignore things such as flywheels, brakes and clutches - they don't change with the spark plug.

 

The exhaust is still off at the moment?

 

So 2 stroke engine - I might be wrong... piston rises compressing the gas / fuel mix above it, spark happens and gas ignites pushing the piston down again which causes air / gas to move above the piston, piston rises and it all starts again/ The exhaust is an open port after ignition the exhaust gases simply escape through this open port.. To allow the piston to move then, air has to move - move out of the way as the piston moves into a space or move into where the piston was as it moves out of a space., or something could be causing extra friction on the piston. (just writing down my thoughts here)

 

If the piston moves with no spark plug in but is hard otherwise... then there is a hole where the sprark plug was above the piston allwoing air freer movement to above the piston, close the hole and it doesn't move freely.  I would be looking at how the air gets in / out of the engine.

 

- There is no exhaust on? So I assume that air exiting is not hindered

- Try putting in the spark plug and take off the carb / loosen it (it doesn't need to come al the way off, just a bit), see what that does - it is possible that the fuel pipes are blocked? then try the saw.

- If you suspect the spark plug is catching then the piston - pulling the engine over will alternate hard and easy pulling as the cylinder moves past the sopark plug and then leaves it behind. Aldo the soark pug will show some shiny sports where the pisotn rubs it.

 

Hipe that helps - but if it iosn't the spark plug then look at the carb. If it is free to move over with spark plug in but no carb on, pout some fresh fuel through into the lower part og the cylinder - pull it over and wioth luck it should start

[EricBradley]

Where in the country are you? One of us maybe local enough to just pop round and take a look.