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New X738

11K views 87 replies 21 participants last post by  CJadamec 
#1 ·
Just had my X738 delivered and I can't wait to use it! I'm impressed with how easy and quick it is to take the mower deck and bagger off. We have plenty of snow up here in Maine so no grass cutting anytime soon. Although I did pull the deck and try the four wheel drive out in the snow! I was honestly impressed with how well it did.

Can't wait to put some hours on it!!
 
#80 ·
Per manual for 738

Starting the Engine

MXAL42688

MXAL42688-UN-22MAR13
CAUTION: Engine exhaust fumes contain carbon monoxide and can cause serious illness or death.
Do not run an engine in an enclosed area, such as a garage, even with doors or windows opened.
Move the machine to an outside area before running the engine.

IMPORTANT: Starting fluid combusts rapidly and can cause internal engine damage.
Do not use any type of starting fluid in cold weather to assist starting. The engine is designed to start in cold-weather conditions. See your authorized dealer for other starting aids for your machine.

NOTE: Depress brake pedal, or lock park brake, before you can start the engine. Be sure that PTO/RIO switch is off.
  1. Lock park brake or depress brake pedal.

  2. MXT013435

    MXT013435-UN-08MAY15
    X710 with standard carburetor shown

    MXT013436

    MXT013436-UN-08MAY15
    Remaining models with EFI engine shown

    Push throttle lever (A) up to between 1/2 and fast position.

  3. Turn key to run position.
  4. Check indicator lights:
    • Instrument cluster does a brief light check
  5. NOTE: You may not need to choke a warm engine.
    Choke engine:
    • Model X710 with cold engine - Push and hold up choke lever (B) all the way.
    • All remaining models with cold engine - Push and hold up throttle lever (C) all the way.
  6. Turn key to start position:
    • Crank engine.
    • If engine does not start within 5 sec., release choke lever or throttle lever, turn key to stop position and wait 10 sec.
  7. Repeat this procedure if necessary.
  8. IMPORTANT: Unnecessary engine idling may cause engine damage. Excessive idling can cause engine overheating, carbon buildup, and poor performance.
    When engine starts, release key, and release choke lever or throttle lever. The key will return to run position and all indicator lights.
OUO2004,0000C3A-19-20150818​
 
#82 ·
This applies only the older series x7 tractors 2013 and older. Past 2013 all x7 tractors are EFI or diesel none of them have a choke.
 
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#81 ·
CJadam I agree a closed loop system would definitely improve how thirsty these engines are but would point out all engines that I am aware of with a feedback system utilizing exhaust gas oxygen sensors start in open loop . It takes a period of time after start up for the sensor to heat up by exhaust and internal heating element to provide feedback to the computer .
 
#83 ·
This is true.

I'm inclined to think the Kawi engine defaults to a richer setting than most closed loop efi systems even at start up.

On a technical note many cars use a heated oxygen sensor to drastically limit the amount of time the car is in open loop startup. Also a heated sensor is more stable during varied engine loads.
 
#85 ·
Normally you would think the throttle position sensor would give enough info to determine the amount of air entering the throttle body regardless of the throttle setting . If the system can establish a warm air fuel mixture I would think the limiting factor is how good the software is at low ambient temps combined with fuel quality crank speed etc. As an example a similar system (open loop) and same sensor configuration is used on my sons snowmobile and it starts perfect at an idle in colder temps than my Lawn Tractor is exposed to . Would be a lot of smashed up sleds if they had to be started at 1/2 to full throttle when using a centrifugal clutch set up. At least the system is reliable , I doubt it would require much tweaking to help the cold starts if JD felt it was a priority.
 
#86 ·
If there was a throttle position sensor on the engine you would be correct.

The EFI system on the x7 engines only has, intake air temp, intake manifold pressure, crank position, and engine coolant temp sensors for inputs. Its a very basic fuel injection system.
 
#88 ·
I had to look at the engine manual myself to be sure.

You made a good point, if there was a throttle sensor it would help the situation a lot.
 
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