Titan ReloadingLee PrecisionMidSouth Shooters SupplyRepackbox
WidenersInline FabricationADvertise hereRotoMetals2

Results 1 to 20 of 20

Thread: Kawasaki engine issues

  1. #1
    Boolit Master Thumbcocker's Avatar
    Join Date
    Oct 2007
    Location
    East Central Illinois
    Posts
    2,896

    Kawasaki engine issues

    Our zero turn has a Kawasaki 24 hp engine. It is turning over slowly and will backfire sometimes. Replaced solenoid and battery. Charged battery fully. No change. Last week it started with the booster pack. Once started it ran beautifully. Did not start tonight with boost pack or battery charger in boost mode. Starter?
    You'll go far providin' you ain't burnt alive or scalped."

    Will Geer as Bear Claw in "Jeramiah Johnson"

  2. #2
    Boolit Master

    Winger Ed.'s Avatar
    Join Date
    May 2007
    Location
    Just outside Gun Barrel City, Texas
    Posts
    2,412
    Quote Originally Posted by Thumbcocker View Post
    Starter?
    That'd be my first guess.

    The backfire might be from it turning over so slowly and not a engine problem.

    I've had one or two on old cars that you could take them apart, clean everything real well,
    if the brushes looked decent-- put them back together and they'd be OK.
    It wasn't playing the blame game, finding fault, and complaining about every little thing that made America great.
    It was God, guns, and guts.


    Never pick a fight with old people.
    If they don't think they can win it: They'll just kill you.

  3. #3
    Boolit Master
    Join Date
    Dec 2016
    Posts
    608
    Maybe a bad ground on the engine block?

  4. #4
    Boolit Master
    Join Date
    Sep 2016
    Posts
    1,396
    Have you cleaned the battery terminals and lugs one the wires?. Had the same or almost the same with mu Kubota tractor. battery posts were black and some corrosion on one of the lugs. used the brush that can clean both the posts and the inside of the terminals or lugs. Started up but turned over slow. Put on 2amp charger overnight. hook the battery up and same thing. New battery time. Recleaned both new battery posts and lugs and started right up in 3 cranks. Old battery kaput. Check your switches as one could be on and you don't notice its on. On my Kubota the light switch is a multi function for headlamps, signal lights and flashers. When I put the new battery in service and sitting in the seat one position looked odd. Yep the 4 way flashers were on but no lights until engine is running. put the switch where it's supposed to be. Frank

  5. #5
    Boolit Grand Master
    Join Date
    Nov 2012
    Location
    Central Virginia
    Posts
    6,536
    That engine has an automatic compression release mechanism that holds the exhaust valve slightly open at very low rpm's (like when first starting to rotate the crank). If that mechanism fails, the starter motor must overcome the full compression of the engine and it will not spin fast enough to start.

    So if you eliminate all of electrical problems (battery, cables, starter motor, etc.) the next place to look for slow cranking is the automatic compression release.

  6. #6
    Boolit Grand Master






    Lloyd Smale's Avatar
    Join Date
    Mar 2005
    Location
    munising Michigan
    Posts
    15,698
    its possible to that because of the compression release they have it programed to advance timing to make it start easier. If the release isn't working it could have to much advance for the compression and actually be detonating (preignition or spark knock in other words)
    Quote Originally Posted by Petrol & Powder View Post
    That engine has an automatic compression release mechanism that holds the exhaust valve slightly open at very low rpm's (like when first starting to rotate the crank). If that mechanism fails, the starter motor must overcome the full compression of the engine and it will not spin fast enough to start.

    So if you eliminate all of electrical problems (battery, cables, starter motor, etc.) the next place to look for slow cranking is the automatic compression release.
    Soldier of God, sixgun junky, Retired electrical lineman. My office was a 100 feet in the air, closer to God the better

  7. #7
    Boolit Master trails4u's Avatar
    Join Date
    Feb 2013
    Location
    Upstate, SC
    Posts
    924
    Quote Originally Posted by Lloyd Smale View Post
    its possible to that because of the compression release they have it programed to advance timing to make it start easier. If the release isn't working it could have to much advance for the compression and actually be detonating (preignition or spark knock in other words)
    I'm of the mind that this is the right track. If it's turning over (ever) I don't think starter, unless I'm not getting the whole picture. I also had a carb issue once upon a time that allowed the cylinder to flood while sitting. Similar symptoms to what you described. Would not turn over unless boosted....as it needed the extra 'oomph' to overcome a cylinder full of fuel. Also smoked a good bit at startup (guessing all the gas washed the cylinder wall pretty good.
    "Do not follow where the path might lead, go instead where there is no path and leave a trail" Ralph Waldo Emerson

  8. #8
    Boolit Grand Master
    Join Date
    Nov 2012
    Location
    Central Virginia
    Posts
    6,536
    It's really not that complex. The cam is equipped with a pin that interacts with the tappet and opens the exhaust valve mid-compression stroke to release the compression. As soon as the cam shaft starts to spin, (like when the engine starts running) centrifugal force pushes a weight outward and that action removes the pin from the path of the tappet. At that point the exhaust valve opens and closes normally and full compression is achieved during the compression stroke.

    The Automatic Compression Release [ACR] allows a smaller starter motor to start the engine but if the ACR fails, the starter motor will need to overcome the full compression of the engine.

    The spring the holds the weights inboard at zero or very slow camshaft rotation is a weak spring. It doesn't take much speed at all to overcome the ACR and return the engine to full compression.

    There is no ignition timing involved in the ACR on a Kawasaki small engine, it is entirely mechanical and it acts on the exhaust valve.

    The OP stated the engine was turning over slowly, which can be caused by the starter working against the full compression of the engine during an attempt to start the engine. So once all of the potential electrical problems are eliminated (starter motor, battery, etc,) the next logical place to look is the ACR. Because the OP stated that the engine ran fine once it started, that also supports the theory the ACR has failed.
    Last edited by Petrol & Powder; 04-05-2020 at 01:34 PM.

  9. #9
    Boolit Master Thumbcocker's Avatar
    Join Date
    Oct 2007
    Location
    East Central Illinois
    Posts
    2,896
    I think I have a new starter motor somewhere. I am guessing that the compression release would be a puppy mother to replace/repair.
    You'll go far providin' you ain't burnt alive or scalped."

    Will Geer as Bear Claw in "Jeramiah Johnson"

  10. #10
    Boolit Master

    rockrat's Avatar
    Join Date
    Aug 2005
    Posts
    4,048
    Pull the spark plugs and see how fast the motor turns over. If still slow, you know then its not the ACR. Check for corrosion on the cable at the starter solenoid and to the starter if separate from the solenoid. Also, the connections from the starter switch to the solenoid

  11. #11
    Boolit Grand Master
    Join Date
    Nov 2012
    Location
    Central Virginia
    Posts
    6,536
    Quote Originally Posted by Thumbcocker View Post
    ...........I am guessing that the compression release would be a puppy mother to replace/repair.
    In a word, YES.
    But;

    A good place to start is to check the valve clearance (valve lash). If there is excessive clearance on the exhaust valve, the ACR will not work well or maybe not at all. So adjusting the valves (setting the backlash) may be all that needs to be done to correct the problem. if you can get to the valve covers, this isn't a difficult job on a Kawasaki.
    If the ACR mechanism on the camshaft is broken, that's a major job.

    And spinning the engine with the spark plugs removed will not tell you much. The starter will have no problem spinning an engine with the plugs out, even if the starter is weak. My experience with electric starter motors is they either work or they don't, there's not a lot of in between.

  12. #12
    Boolit Master
    Join Date
    Nov 2014
    Location
    'Bout a hundred miles from the Gulf of Mexico
    Posts
    717
    ^^^^^^^^^^^^^^^^^^^^^ what he just said!!!!! If lots of hours on engine, valve lash will change. just my experience. Good luck.
    I firmly believe that you should only get treated by how you act, not by who or what you are!!

  13. #13
    Boolit Master
    Join Date
    Nov 2017
    Location
    brisbane ,qld,australia
    Posts
    1,076
    My brothers mower had one of these engines ,rebuilt for head gasket leak once,was running well ,but recently it dropped a valve and wrecked ....seems wise ,he says ,to renew the keyhole type valve retainers and valves ,as a retainer fail was the cause of the wreck.His wife was running the mower,possibly there was a warning noise ,but unfortunately the motor was run to destruction.

  14. #14
    Boolit Buddy Rapidrob's Avatar
    Join Date
    Jun 2009
    Posts
    152
    You said it was working normally then not. This rules out a lot of problems.
    Basic trouble shooting is key. Look at simple fixes first.
    Fuel: how old? Water in it? Fuel filter clogged? Tank strainer plugged? Remove it and try to blow through it. If hard to do it is clogged. A normal breath should go right through. Drain the carb. Make sure the fuel is clean and smells normal. Alcohol in the gas attacks the aluminum in the carb and causes all sorts of problems. Clean it if needed.
    Linkage bent or missing to the carb and governor?
    Air: Air filter clogged? Full of old grass/dirt/mouse nest? If it has a foam band on it make sure it too is clean. Try to start it with the filter off.
    Spark plug(s) Remove them and ground them to the engine, do they spark BLUE? Orange is a bad plug. MANY of the spark plugs sold today are phony Chinese crap. They look real but are not. I've had Three fail this year alone,this has never happen in my 57 years working on small engines! Buy real NGK's their the best IMHO.
    Make sure the pick-up coil adjustment is correct. A loose coil will cause problems.
    Battery: As stated above check all wiring to ground and positive. Lawn mower batteries suck. Poorly made with a short life.Try jumping the battery with your car/truck or spare known to be good battery.
    If these things all pass with flying colors, THEN check for a mechanical malfunction. Such as a lose/broken shaft key holding the flywheel in time. Hitting a large rock or branch can cause this.
    Check the simple things first. It WAS running now not.Sitting all winter always has me checking all I have posted.

  15. #15
    Boolit Grand Master
    Join Date
    Nov 2012
    Location
    Central Virginia
    Posts
    6,536
    What the OP wrote was that it was turning over slowly but once it started - it ran beautifully.

    Because that engine is equipped with an Automatic Compression Release [ACR]; a malfunctioning ACR will result in the engine turning over slowly. (the starter is fighting against the full compression during the attempt to start).
    Because the ACR works by slightly opening the exhaust valve during the compression stroke, excessive valve lash on the exhaust valve side will prevent the exhaust valve from opening when the ACR is in play (during attempts to start the engine). Once the engine is running the ACR is no longer in play and the engine will run fine. This explains why the engine ran "beautifully" once the OP got it started.
    Last edited by Petrol & Powder; 04-06-2020 at 08:38 AM.

  16. #16
    Boolit Man 1006's Avatar
    Join Date
    Apr 2013
    Location
    South of Atlanta, GA
    Posts
    80
    Make sure the fly wheel has not twisted on the shaft, making the engine out of time.

    I had that happen on a Kohlar Command engine, with the compression relief setup similar to the Kawasaki. It had the same symptoms you are having.

  17. #17
    Boolit Grand Master
    Join Date
    Nov 2012
    Location
    Central Virginia
    Posts
    6,536
    From the OP:

    "Our zero turn has a Kawasaki 24 hp engine. It is turning over slowly and will backfire sometimes. Replaced solenoid and battery. Charged battery fully. No change. Last week it started with the booster pack. Once started it ran beautifully...…………."

  18. #18
    Boolit Master Thumbcocker's Avatar
    Join Date
    Oct 2007
    Location
    East Central Illinois
    Posts
    2,896
    I am going to check the valve clearance tonight. Just got a set of feeler gauges.
    You'll go far providin' you ain't burnt alive or scalped."

    Will Geer as Bear Claw in "Jeramiah Johnson"

  19. #19
    Boolit Master Thumbcocker's Avatar
    Join Date
    Oct 2007
    Location
    East Central Illinois
    Posts
    2,896
    Adjusted the valves to .004. IT STARTED!!
    Petrol&Powder was right.
    You'll go far providin' you ain't burnt alive or scalped."

    Will Geer as Bear Claw in "Jeramiah Johnson"

  20. #20
    Boolit Grand Master
    Join Date
    Nov 2012
    Location
    Central Virginia
    Posts
    6,536
    Quote Originally Posted by Thumbcocker View Post
    Adjusted the valves to .004. IT STARTED!!
    Petrol&Powder was right.
    You're Welcome !

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check