2020 Toro Z-Master 2000 - cold starting

Proctor164

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Hi Everyone - have a new z master 2000 60" with the Toro 24.5 commercial engine. Model 74494. Everything was perfect until the weather turned cooler - now the engine is hard to start! Half-throttle and choke pulled out...it cranks and cranks. Eventually does go, but this can't be normal...especially considering it started easily during warmer temperatures. Starts fine on a warm re-start. Nothing appears wrong...any ideas? A common issue for the Toro 24.5 engine?
 

Scrubcadet10

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Check to be sure the choke is closing all the way, if you remove the air filter cover and box, or the air intake hose, you should be able to see the choke valve in the carburetor, when the mower is choke position, see if you can close them further by manually pushing the choke shaft on top.
 

Proctor164

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Check to be sure the choke is closing all the way, if you remove the air filter cover and box, or the air intake hose, you should be able to see the choke valve in the carburetor, when the mower is choke position, see if you can close them further by manually pushing the choke shaft on top.
Thanks for the reply. I will check on this. Has it been a common issue on these engines? It has less than 10 hours on it. FANTASTIC machine aside from this issue
 

Scrubcadet10

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it can pretty much happen on any engine, usually over time, but this may be a case of poor adjustment from the factory.
 

Skippydiesel

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As a general principal, a carburetted engine should not be started with throttle advanced and choked at the same time - If your manual says to use throttle, only use very very little - fast idle position only.
Many of the smaller, usually single cylinder engines, have throttle/choke on the one lever - in this case the manufacturer has designed the system, to cold start with wide open throttle and closed choke, you have no choice in the matter and it usually works quite well.
With larger engines, that have been fitted with a separate choke, opening the throttle fights/apposes the closing of the choke - so starting will be difficult (particularly in cold weather).

With my larger mowers, for a cold start,
  • I make sure the throttle is fully closed.
  • I close the choke fully (usually a pull up button ).
  • Crank the engine very briefly.(If no immediate start, do not continue cranking, as this may flood your carburettor and stresses your starter motor/system unnecessarily)
  • If start, I allow engine to run for a few seconds, until I can hear a change in engine note, I then slowly open (push down choke button) until smooth idle is achieved.
  • If no start, I open my throttle very slightly, to fast idle position (no further) and crank again. I always get a start at this point, no matter how cold or long, it has been sitting. Again I wait until the engine note changes and I start to open the choke gradually (push down choke button) until smooth idle is achieved.
Note: Always allow a few moments/minutes for your engine to warm up. Engaging drive or cutter system, when engine is still cold, is likely to cause it to run roughly or even stall. At the end of work allow a few minutes for cool down befor shutting off (this is the time I take to blown clean my mower)
 

Skippydiesel

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I forgot to mention:
If you inadvertently flood your engine.
Do not keep cranking/ trying to start - this will just make the situation worse, overheat/damage your staring system and drain your battery
Open the choke fully (choke button down/in all the way)
Open throttle all the way.
Place hand on starter motor - if cool proceed - if warm/hot wait until cool.
Crank engine - should fire and run within a few revolutions. If fires and "dies" reduce throttle to fast idle position & try again.
Reduce throttle to fast idle
Allow engine to warm up.
 

Skippydiesel

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I was quite specific about engines fitted with a separate choke control V engines with a combined throttle/choke.

I stand by my advice, for engines fitted with separate throttle/choke controls, to have the throttle closed or at most open a "smidgeon" for cold starts.Try it - you will get far more reliable starts.
 

bertsmobile1

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It should make no difference to a governed engine because the governor will have the throttle WFO while cranking till it fires .
 

Rivets

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