OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions on Other Engines Rover 2 stroke Suzuki hard to pull start

Hi everyone, I have a Rover Suzuki M120X 2 stroke mower.

It's now hard to pull start with the plug in - gets stuck on compression stroke. It spins easy with the plug out.

My brief research suggest some sort of overpressure, but these engines don't seem to have pressure relief valves?

Any ideas?

Take off the exhaust, you'll find a decompression hole in the port towards the top, make sure its not carboned over as this will greatly reduce the high comp you are experiencing. There's a good thread here with an image of the port
Suzuki 2 stroke

Thank you! The port is squeaky clean and it's still happening.

I wonder if it's some sort of hydrolock? The combustion chamber is clear but could there be something in the crankcase?

Maybe try fitting a Victa decomp valve to the head I have done that to a couple of bigger Briggs 4 stroke motors with great success

Hi SuziRova

If the starter handle is ripping out of your hand when starting or the handle has a sudden stop it could be a broken blade hub key or flywheel key ,a faulty spark plug will misfire.

If the key on the blade hub is broken or sheared, it could cause the blade plate to slip or become loose on the crankshaft. The blade hub helps provide rotational mass (flywheel effect), and if it's not rotating correctly, you might feel the pull start jerking, binding, or becoming difficult to pull.

A broken flywheel key (which keeps the flywheel in place on the crankshaft) can also cause starting issues, especially if it results in a misfire or if the timing is off. This can lead to uneven or erratic resistance when pulling the starter rope, potentially giving you that "sudden stop" or feeling of it being hard to pull.

If the carburetor is over-fueling, it means too much fuel is being mixed with air, causing a rich mixture (too much fuel and not enough air). This can make the engine run poorly or make it hard to start.

When you try to pull-start, the engine might flood (get too much fuel) and have difficulty starting. It could lead to the starter handle jerking or becoming harder to pull because the excess fuel makes the engine harder to turn over.

Sticking or Dirty Carburetor Needle and Seat:

If the needle valve or seat is worn, dirty, or stuck, the carburetor may continuously allow fuel into the bowl, leading to over-fueling.

This can cause the carburetor to constantly flood the engine with more fuel than needed.


Cheers
Max.

Thank you both! I'll look into this in more detail next week