I'll take a closer look at the Ariens tonight. I just got this blower free from someone who got a new one. He got it free frome someone else a while back. Looks like an after market electric start on this thing, so there isn't a shroud piece besides or around the plug. Looks like this piece may have been removed to fit the electric starter plug/button.

Air starvation is what I was indicating from your description of starts easier with the air filter off allowing adequate air to fuel mixture. As JL has advised dirty or loaded filter medium will cause this extreme condition. However as JL has requested (orientation) if the hose connects to the venturi area of the carb it will have a direct effect on air entrainment into the fuel air mixture. As we have stated previously , not having you engine at arms length make diagnosis rather difficult (hit & miss) . A torn or cracked or loose impulse line is something any technician inspects and replaces as a matter of fact. This from a former diesel mechanic who has chased numerous vacuum / return to tank fuel line issues causing air entrainment hard or no start diesel applications . Anyhow for what ever reason glad you have solved your hard starting dilemma :)

Thanks for info. What I was referring to was just moving the shift lever through the gears with engine not running and clutch not engaged. It seems stiff moving from one gear to another. When engine is running and I change gears by engaging the clutch, the stiffness is still there. Maybe this is just wear as tractor is now just under 20 years old. Are there any areas to lubricate on linkage that I have not mentioned above? Jim

Isn't this kind of work fun? The only time you can measure and test for the problem is while it's happening. Any other time that the car actually starts, everything you test will be "spot on" as you put it. Which is a reference to the most likely suspect for your mothers car's symptom. Low fuel pressure I.E. a bad pump. These things will not start with 54PSI of fuel pressure, they must achieve 56PSI! Your gage has to be accurate within 1PSI in that range to actually see this occuring. The thing is, hitting this with a little ether (I prefer propane) will give it some fuel to burn and increase manifold vacuum, and often times allows the car to start, because the vacuum actually helps open the poppet injectors. The poppet injectors are why this thing needs a minimum of 56PSI to start. Other things to consider. "Spark volume" I know you replaced secondary ignition, did you clean the breathers in the base of the distributor? They tend to clog, and then crankcase gasses will collect in the distributor causing corrosion, and then the spark will short to ground inside the distributor. Fuel: It takes more than just fuel pressure to ensure the engine is getting fuel. The injector must be triggered on by the PCM. I have had the two wire connector between the engine harness and the injector corrode and cause a loss of injector command. Plus you need to have a good crank signal trigger to not only tell the computer to drive the injector, but to command the module to trigger the coil. Tell me, when the car acts up. Key on, you hear the pump run for two seconds. Start cranking the engine, do you hear the pump turn back on? This would tell me if the PCM sees the signal from the crank sensor.