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42 inch riding mower (1742) won’t crank

#1

2

2002sheds

Hi All,

I have a Scotts-branded 1742 riding mower made by John Deere. About 500 hours on the machine.


Typically, it is difficult to get the mower started in the Spring after sitting all winter. A few times the issue was solved with a new carburetor, but this time it is a different problem…
I cannot get the mower to turn over for very long at all (like 5 seconds). I have removed the spark plug and turned the flywheel by hand, I’ve replaced the battery, solenoid and starter and I have connected a battery charger/starter with only a small difference in how long the motor will crank before (seemingly) wiping out the battery’s amperage.
I also tested the ignition switch, which tested okay, and I made certain that the ground strap had a good, clean connection to the frame, as well as at the battery. And I even stuck a borescope into the cylinder and found no scoring or anything else unusual.
At one point, I was able to crank the motor for an extended period of time before shutting it off — like 15 seconds or so. The spark plug was still out, as I was simply trying to find ANY scenario in which the engine turned over. Since then, I have only had one instance where the motor turns for more than 3 or 4 seconds before giving out, stranding the Bendix gear in the up position…

Any hints as to why it is so hard to crank this motor over will be greatly appreciated!


Thanks,
David


#2

Tiger Small Engine

Tiger Small Engine

2002sheds said:
Hi All,

I have a Scotts-branded 1742 riding mower made by John Deere. About 500 hours on the machine.


Typically, it is difficult to get the mower started in the Spring after sitting all winter. A few times the issue was solved with a new carburetor, but this time it is a different problem…
I cannot get the mower to turn over for very long at all (like 5 seconds). I have removed the spark plug and turned the flywheel by hand, I’ve replaced the battery, solenoid and starter and I have connected a battery charger/starter with only a small difference in how long the motor will crank before (seemingly) wiping out the battery’s amperage.
I also tested the ignition switch, which tested okay, and I made certain that the ground strap had a good, clean connection to the frame, as well as at the battery. And I even stuck a borescope into the cylinder and found no scoring or anything else unusual.
At one point, I was able to crank the motor for an extended period of time before shutting it off — like 15 seconds or so. The spark plug was still out, as I was simply trying to find ANY scenario in which the engine turned over. Since then, I have only had one instance where the motor turns for more than 3 or 4 seconds before giving out, stranding the Bendix gear in the up position…

Any hints as to why it is so hard to crank this motor over will be greatly appreciated!


Thanks,
David
Click to expand...
So you have installed three new carburetors, starter, solenoid, and battery in the last few seasons? Why would you need to have the engine crank for longer than say 5 seconds? An engine that is running right typically fires right up. Have you gone through and done a complete tune up service? Are you sure the fuel is good? (Fresh and no water in fuel). Have you adjusted the valves?


#3

2

2002sheds

Hi Tiger,

Thanks for the reply. I have replaced the carburetor once or twice in the last few years and replaced the battery, solenoid and starter this go around. I have not yet adjusted the valves (I hope to get to that later today when the rain stops), and I do have fresh fuel with no water in it. I was hoping it would start immediately, but was continuing to crank the motor in order to get fuel to the new carburetor (which maybe you are saying is still longer than needed). I will report back later today after I adjust the valves and charge the battery.


Thanks,
David


#4

StarTech

StarTech

If I found the correct IPL (S1742) you have a single cylinder OHV Briggs engine. IF so then most likely one of two things is the problem especially if the engine is stopping the top of the compression stroke.
  • Valves are out adjustment causing the ACR not to work or
  • The ACR on the camshaft is broken which is common on these engines.
When adjusting the valve the lower rocker (furthermost from the flywheel) is the intake. Once the valve is adjusted to .003-.005 you should the ACR bump the rocker as the engine engine approaches TDC compression stroke. If not present the camshaft's ACR is broken. And the exhaust is adjusted to .005 - .007
ACR = Automatic Compression Release


#5

2

2002sheds

Hi Star,

Thanks very much for the reply. The engine is a 17.5hp Kohler Command, Model CV491S. I will research the valve clearances and whether this engine has an ACR and bring the results back to this forum later this afternoon, when the rain is supposed to end.


Thanks,
David


#6

StarTech

StarTech

Being a Kohler CV series the valve are none adjustable normally as the engine uses hydraulic lifters; therefore, camshaft would not have an ACR on it.

But the CV491-27509 spec does have a camshaft with an ACR on it. The problem if the ACR is broken you can't replace the camshaft with a new one as the Kohler has NLA the camshaft.
1714837815139.png1714837844771.png


#7

2

2002sheds

Hello Star,
Thanks again for your reply. Things are starting to make more sense (even if I don’t like some of the possibilities).


UPDATE: I just checked the photo of the mower’s ID label, and indeed the one I have is the dreaded CV491-27509… is there a way to get a peek at the camshaft to see if the ACR is broken/hung up?


Thanks,
David


#8

2

2002sheds

Hello Star,
Thanks again for your reply. Things are starting to make more sense (even if I don’t like some of the possibilities).


I just confirmed that the mower I have is the dreaded CV491 spec 27509… is there a way to get a look at the camshaft to see if the ACR is broken? And can just the spring be replaced if it is the issue, or is the camshaft assembly just that — all one unit?

Thanks,
David


#9

2

2002sheds

Hi Star, All,
My questions about inspecting the camshaft without tearing the motor completely apart and whether or not the spring on the ACR can be repaired or replaced just became more urgent, as I have learned that I will not be able to replace the mower with a similar gas model due to air quality laws changes in our area.

Any info about getting at the camshaft (I do have a borescope) and/or the viability of repairing the ACR will be greatly appreciated.

Thanks,
David


#10

2

2002sheds

2002sheds said:
Hi Star, All,
My questions about inspecting the camshaft without tearing the motor completely apart and whether or not the spring on the ACR can be repaired or replaced just became more urgent, as I have learned that I will not be able to replace the mower with a similar gas model due to air quality laws changes in our area.

Any info about getting at the camshaft (I do have a borescope) and/or the viability of repairing the ACR will be greatly appreciated.

Thanks,
David
Click to expand...


#11

2

2002sheds

Hi All,

Well, I received no more responses to my questions, and so I kept asking around and searching online until I found the answer myself. The camshaft on this motor is no longer available, but the spring can be removed and is available as a separate, $2 part.

I am posting this in case someone stumbles across this thread and is as mystified as I was. I hope this helps!


Thanks,
David


#12

Tiger Small Engine

Tiger Small Engine

2002sheds said:
Hi All,

Well, I received no more responses to my questions, and so I kept asking around and searching online until I found the answer myself. The camshaft on this motor is no longer available, but the spring can be removed and is available as a separate, $2 part.

I am posting this in case someone stumbles across this thread and is as mystified as I was. I hope this helps!


Thanks,
David
Click to expand...
The answer on how to check to see if the compression release is working was given, in this thread. You rotate the engine by hand very slowly, and watch the intake and exhaust valves as they go through the four strokes. You are looking for “the bump” of when the valve just moves slightly up and down, in addition to the normal movement. Could be the intake and could be the exhaust, depending upon the engine. If there is no additional “bump”, then compression release mechanism on camshaft is broken. Aftermarket camshafts for this engine my be available.


#13

S

SeniorCitizen

With 500 hrs on a home owner battery it's time for a new battery and by al means clean the battery cable ends of oxidation until you see the metal shine .


#14

H

hlw49

Tiger Small Engine said:
The answer on how to check to see if the compression release is working was given, in this thread. You rotate the engine by hand very slowly, and watch the intake and exhaust valves as they go through the four strokes. You are looking for “the bump” of when the valve just moves slightly up and down, in addition to the normal movement. Could be the intake and could be the exhaust, depending upon the engine. If there is no additional “bump”, then compression release mechanism on camshaft is broken. Aftermarket camshafts for this engine my be available.
Click to expand...
It will be the valve closest to the cam gear which in this case it is the exhaust valve.


#15

S

Skippydiesel

If cranking speed is slow/laboured (even with a new starter) try improving the (-) ground /earth return by using a jump cable between (-) battery ground/earth and anywhere you can get a good connection on the engine.

!2 Volt systems are notorious for developing (corrosion/loose connection) a poor (-) ground/earth return. Clean ALL your earth return connections, making sure they are tight.

I do not rely on the earth return through chassis/body and install a dedicated earth return on all my own machines, running from battery (-) to any suitable point on the engine (usually a engine securing bolt) and rarely have electrical problems.


#16

M

mcHarley

2002sheds said:
Hi All,

I have a Scotts-branded 1742 riding mower made by John Deere. About 500 hours on the machine.


Typically, it is difficult to get the mower started in the Spring after sitting all winter. A few times the issue was solved with a new carburetor, but this time it is a different problem…
I cannot get the mower to turn over for very long at all (like 5 seconds). I have removed the spark plug and turned the flywheel by hand, I’ve replaced the battery, solenoid and starter and I have connected a battery charger/starter with only a small difference in how long the motor will crank before (seemingly) wiping out the battery’s amperage.
I also tested the ignition switch, which tested okay, and I made certain that the ground strap had a good, clean connection to the frame, as well as at the battery. And I even stuck a borescope into the cylinder and found no scoring or anything else unusual.
At one point, I was able to crank the motor for an extended period of time before shutting it off — like 15 seconds or so. The spark plug was still out, as I was simply trying to find ANY scenario in which the engine turned over. Since then, I have only had one instance where the motor turns for more than 3 or 4 seconds before giving out, stranding the Bendix gear in the up position…

Any hints as to why it is so hard to crank this motor over will be greatly appreciated!


Thanks,
David
Click to expand...
I also think, could be an valve issue, check also if the flywheel key isn't broken (timing issue.)


#17

K

Keithpeb

I have just had a similar problem with my 3 year old mountfield ride on mower. It has stayed outside since purchase. Went to it for first cut, no click or anything. Long story short, starter motor had rusted fairly solidly so pre engage not moving either. Turned it bit by bit with a screwdriver to get it moving and its now free and running no problem. Access was by removing the tor fan/engine cowl. Yours maybe the same, worth a look before you cover the floor with mower bits.
Regards
KeithP


#18

L

lefty2cox

Do we know if the OP has done a voltage drop test at the starter?


#19

2

2002sheds

Tiger Small Engine said:
The answer on how to check to see if the compression release is working was given, in this thread. You rotate the engine by hand very slowly, and watch the intake and exhaust valves as they go through the four strokes. You are looking for “the bump” of when the valve just moves slightly up and down, in addition to the normal movement. Could be the intake and could be the exhaust, depending upon the engine. If there is no additional “bump”, then compression release mechanism on camshaft is broken. Aftermarket camshafts for this engine my be available.
Click to expand...
Hi Tiger,

Thanks! I didn’t know about that thread — I will check it out and then know if it is truly an ACR issue. Interestingly, my question about access to inspecting the camshaft was not addressed, but I have since purchased a used John Deere, so I will come back to this as time allows.

Thanks,
David


#20

2

2002sheds

SeniorCitizen said:
With 500 hrs on a home owner battery it's time for a new battery and by al means clean the battery cable ends of oxidation until you see the metal shine .
Click to expand...
Hi Senior,

Battery was replaced, as described earlier in the thread.

Thanks,
David


#21

2

2002sheds

Skippydiesel said:
If cranking speed is slow/laboured (even with a new starter) try improving the (-) ground /earth return by using a jump cable between (-) battery ground/earth and anywhere you can get a good connection on the engine.

!2 Volt systems are notorious for developing (corrosion/loose connection) a poor (-) ground/earth return. Clean ALL your earth return connections, making sure they are tight.

I do not rely on the earth return through chassis/body and install a dedicated earth return on all my own machines, running from battery (-) to any suitable point on the engine (usually a engine securing bolt) and rarely have electrical problems.
Click to expand...
Hi Skippy,

All connections were cleaned, scraped and even sanded (where appropriate)…

Thanks,
David


#22

2

2002sheds

mcHarley said:
I also think, could be an valve issue, check also if the flywheel key isn't broken (timing issue.)
Click to expand...
2002sheds said:
Hi Tiger,

Thanks! I didn’t know about that thread — I will check it out and then know if it is truly an ACR issue. Interestingly, my question about access to inspecting the camshaft was not addressed, but I have since purchased a used John Deere, so I will come back to this as time allows.

Thanks,
David
Click to expand...
Hi Keith, Lefty,

Thanks for the posts! No voltage drop at starter, and flywheel key appears to be intact. The valves are hydraulic on this model, so no a ability to adjust them.


Thanks,
David


#23

2

2002sheds

Hi All,

Thanks for the many replies. I was in a jam because our rainy season was just ending and lots of sunshine and somewhat cool weather was allowing the grass and weeds to grow quickly, so I found a compatible John Deere D110 riding mower minus the deck for sale and swapped the deck, allowing me to knock down the taller stuff (VERY slowly) and cut the grass portion of our lawn.



I appreciate the responses and have learned a lot about the Kohler engine that came with the Scotts S1742 mower that all of this fuss is about. As soon as I have a few hours ( not right away), I will first do the slow rotation by hand to confirm that it is indeed an ACR issue, and then remove the engine and oil sump in order to replace (I hope) just the spring for the ACR, since the camshaft is obsolete.


I also learned along the way that Kohler engines are worth the trouble… and I hope to have a reliable lawn tractor (if not a mower) after resolving the issue.


Thanks again for the help — I appreciate it!

David


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