So, has anyone had the problem I am having on this Kawasaki engine? I have been troubleshooting to find out why it is backfiring. You will see that I have reset the valves, put on a ne head gasket, and checked the flywheel key. In a previous video, I put on a new coil, new ignitor, and spark plug boot and finaly good a good stron spark. It is still backfiring! Let me know what you think. I would appreciate some helpful comments and feedback.
I had the same problem with same mower. I did everything you did. Just for the heck of it I put a new carburetor on it and I’ll be damn it started right up and stop backfiring. Maybe I got lucky but I thought it would be easy and try it for the heck of it . Have a few of those cheap Chinese carburetors from eBay laying around new in box. Hopefully you get it. when you had the valve cover off did you turn the engine over slowly by hand to see if each valve moved about the same lift. If they are not moving about the same it could be the lobe on the camshaft is worn
@@SmallEngineDIY Have you set both the intake and exhaust valves to 6 thou? Reading online I'm seeing someone has fixed this by setting the ignition coil to .3mm I like head scratchers, especially if we all learn something in the end. I'm curious as to what the fix will be.
I just had the same issue with my 25hp twin kawasaki, it felt like the timing was wrong but it cant be, the issue is that because the ignition timing is on the crank and not the cam meaning that the spark is on compression and a wasted spark on exhaust stroke, there for if the coil does not have enough spark it will not fire on compression but will fire on exhaust which has a fuel mixture in it because it did not fire on compression there for bang out exhaust and carby.
That makes the most sense. I have put on a new plug, but not a new coil. But does that also apply if the back fire is thru the carb? Because that would mean that the intake valve has to be open. And I know that my valves are operating correctly. Yet I still have the back fire thru the carb, big time.
Weak magneto coil. Spark outside cylinder is different than under pressure. That's why it works when you use a spark plug with a lower resistance rating.
I got the same problem with my kohler courage 20 but mines isn't back firing. It's just spinning and then the starter acts like it wants to hang up and then the fuse blows
Hi from Gil take the kill wire off of the ignition coil water can get into the ignition switch and start shorting the coil circuit when engine speeds up also some of the non oem coils can be doing it spark doesn’t mean it’s ok test ohms to block from plug wire and block to kill tab Kill tab. To plug wire look for high ohms or open I had a eBay coil that would start and run backward ccw the new coils have electronics built in them 20:3520:35 advance retard that fail and will drive you nuts crank compression should be 60 psig check the resister in the spark plug or change it the compression release could be stuck Engaged
Did you use lapping compound on the valves? It sounded like the intake valve wasn’t closing properly. Also when you take the head off you can put water in the intake and exhaust ports and check for leaks around the valves. It won’t hurt anything, if you’re worried about using water blast it out with some carburetor cleaner or something when you get done.
This may be to late for you but I had a briggs 20 hp do the same thing I reseated the valves and it worked for some reason because like yours they looked good go figure
I went through all the same things you have including lapping in the valves to no aval. I had spark and discounted that as the problem. I finally installed new coil and igniter and it solved the problem. would it be possible that the igniter even though new is still not functioning correctly?
Check your spark putting in line tester check your spark for it sounds like your coil is going out or is gone out also use a little hit of fogging oil or starting fluid it has to have done something probably the coil went out that's why it died or is going out it's a weak spark I just have to have fire and gas and it will run
I know this is an old post, but did you ever find the problem? I have a Kawasaki fc540v doing the exact same thing. Had it running after changing igniter, fuel pump, carb, fuel shutoff solenoid, spark plug, fuel lines. Sat idle for a week, went to start and won’t fire and backfires very loudly.
Wow...I'm in the process of tuning and fixing up my JD GT275 with the FC540V. New hood and muffler. Then two days ago it did the same thing yours is doing...including a LOUD backfire. It actually ran well enough to make it around the block, but I could feel puffs of air coming out of the air filter inlet. I thought it needed a valve adjustment. Turned out it's a broken intake valve spring.
@@clutch5sp989 remove the valve cover and look for a broken valve spring. Easy to confirm or exclude this cause. I replaced the spring myself. I videoed the process, just haven’t had time to edit and post.
@@jedi_mapperp4073 OK...today I pulled the plug and checked having NO SPARK. Put a new plug in and had spark. WoW...nothing is supposed to be that easy to fix. I have never seen a plug go bad and not work.
@@jedi_mapperp4073 Also...when it cools off a little more here in TX, I'll pull the cover & check clearances. That and many other mech projects to tackle.
Definitely a timing issue. If the valves are not sticking and the valve springs are good, then maybe a camshaft to crank misalignment. Seems that would be quite odd from the way it just quit. That it fires out both the intake and the exhaust indicates either the timing keeps changing or both valves are sticky and are taking to long to close. Try some carb or parts cleaner in the valve guides if you think they are sticky. Make sure both springs are not broken. Other possibility is the timing gears are slipping. Those would be the mechanical things to look at. If I understand right there are no points. That means it must have a cam or crankshaft position sensor to control the timing, which then activates the ICM. Could be a bad sensor or loose screw/wire, or bad ICM. Those darn electronic ignition modules and sensors can be a pain. Give me the old points and condenser any day, much easier to tell if something is good or bad. I thought is was either a head gasket or slipped flywheel key. Had the latter happen to me once. I would start with the sensor and ICM, make sure it has ground good. I gather you have checked the timing and the spark after it quit running. Let us know how it goes. Would really like to see what the fix is. One other thing to check is that the battery voltage is not low, and the charging system is working. Some electronics do not work very well when the voltage is just a tad low. Maybe try running it with a charger hooked up, or a boost from a running vehicle, or good battery.
My FC540V just recently did this. I'm still working on it but I do know if I pour just a little gas straight into the carburator, it will run for a few seconds, making me think it's not a timing issue.
@@philliphall5198Sorry, didn't really think anyone read my comment. It turned out I had water in the gas. Pretty sure it was from the ethanol gas. I would much prefer to run straight gas in my mower but unfortunately there aren't any gas stations near me that sell straight gas. Anyways, I drained all of the old gas out and put in fresh and it ran just fine. Because of the issue I was having, I took the carb apart and cleaned it which it really needed.
I have a Craftsman with a Kohler Pro 16hp CV16S and when it's on idle it purrs like a kitten. Run it up to speed and it sounds like a jalopy! Keyway is perfect. Can't adjust valves. Pushrods are perfect. Switching out w a new carb and spark plug and we'll see how that goes.
Hopefully this will help you. UA-cam: "Why your lawn mower or generator backfires/misfires and how to fix." EASY. The presenter gives a great explanation. Back to the valves, he said it is 100% of the time the Valves also check the flywheel key, which also goes to the valves for timing. I have the same problem with my DR Mower with a Kawasaki FC 420V. The presenter said "Try tapping the intake valve with a soft mallet" to break loose the buildup on the valve. The additives in the gasoline build up around the Intake Valve. Hopefully this will resolve both of our problems since they appear to be the same. If it is the exhaust valve, it will normally have a bent stem.
I think you're on the right track with timing. I agree with what someone else said to watch the valves to get any hints on possible cam issues. If it's not the lobes then maybe the gear not lining up properly? But how does that become misaligned after running properly? Maybe broken teeth on cam gear? Definitely puzzling. Keep us posted
i have 2 mowers with the same engine , and 3 with the slightly larger fc540v engines . they're really particular about the plug . i've had them that would spark real well with plug out of engine , but wouldn't when plug was installed . swapped the plug from one that ran , and it would start then . usually though , the igniter has gone bad .
Thanks for the video bought one yesterday of course it had no hood. It was raining on the way home now the symptoms are the same I have a fan on it let it dry out. We will see Update fan did the trick runs great
This john deere i have backfires so loud when it turns too much and i hate it i had a craftsman older but it started every time first try even after a long chrismas
Leak down test, spark test, plug test, flywheel magnetic in correct place to fire on compression, valve movements, fuel pump test and starting fluid test
My 170 does this and I just feather the choke down and it fires up. So maybe full choke first few cycles and then when it starts puffing I back it off and it fires up. I’m no small engine mechanic but it’s been like this for 5 years since I bought it. Runs every summer like a top lol.
Here's what I think it is myself. It's one of three/3 things valve sticking& not seating properly.,or the lifters need readjusted again. It could be from A blower head gasket aswell to.
This happened to me I bought the lawn mower the breather cover was removed the the oil had water in it. I could get it to run but it kept backfiring ended up just switching the engine
@@SmallEngineDIYI cut with it almost every weekend 1 to 1/1/2 acres. I thought of getting another JD sometime soon but I have wondered if there is anything comparable to this one today. I am in limbo. :)
So, has anyone had the problem I am having on this Kawasaki engine? I have been troubleshooting to find out why it is backfiring. You will see that I have reset the valves, put on a ne head gasket, and checked the flywheel key. In a previous video, I put on a new coil, new ignitor, and spark plug boot and finaly good a good stron spark. It is still backfiring! Let me know what you think. I would appreciate some helpful comments and feedback.
I had the same problem with same mower. I did everything you did. Just for the heck of it I put a new carburetor on it and I’ll be damn it started right up and stop backfiring. Maybe I got lucky but I thought it would be easy and try it for the heck of it . Have a few of those cheap Chinese carburetors from eBay laying around new in box. Hopefully you get it. when you had the valve cover off did you turn the engine over slowly by hand to see if each valve moved about the same lift. If they are not moving about the same it could be the lobe on the camshaft is worn
@@thunderroad7289 Good pointer. I'll try cleaning the carb first and see what happens.
Small Engine DIY Let us know , I'm no expert - but I'm puzzled also .
@@SmallEngineDIY Have you set both the intake and exhaust valves to 6 thou? Reading online I'm seeing someone has fixed this by setting the ignition coil to .3mm I like head scratchers, especially if we all learn something in the end. I'm curious as to what the fix will be.
Are you sure it’s just not flooded?
I understand everyone when they say timing issue. I had the problem on a 460, same thing . I changed the carb, makes no sense to me, but it worked.
I just had the same issue with my 25hp twin kawasaki, it felt like the timing was wrong but it cant be, the issue is that because the ignition timing is on the crank and not the cam meaning that the spark is on compression and a wasted spark on exhaust stroke, there for if the coil does not have enough spark it will not fire on compression but will fire on exhaust which has a fuel mixture in it because it did not fire on compression there for bang out exhaust and carby.
This makes sense. I had these same problems and finally changed coil and igniter and it solved the problem.
That makes the most sense. I have put on a new plug, but not a new coil. But does that also apply if the back fire is thru the carb? Because that would mean that the intake valve has to be open. And I know that my valves are operating correctly. Yet I still have the back fire thru the carb, big time.
Yes at TDC on exhaust stroke both valves are open, on the rocker on the cam.@@4569badboy
so what would be the fix?
Good comment sir..
Weak magneto coil. Spark outside cylinder is different than under pressure. That's why it works when you use a spark plug with a lower resistance rating.
I just pickup a JD 170 FC420v and it’s got that same problem, working on it now.
Good luck!
hi did you find the problem?
Attach the igniter to the dipstick for a better ground? Seen someone else do it and it worked🤷🏼♂️
LOOK AT THE COIL WIRE FOR CRACKS IN WIRE TO THE PLUG. PLACE RAG UNDER WIRE TO TEST. IT MAY BE ARCING TO MOTOR.
I wish people would use the right descriptive term. Cranking means the starter is spinning the engine. When it fires up it is running, not cranking.
When u had the head off I noticed both valves were in, could u have a lose valve guide...
I checked them. The valve guides are OK.
I have exactly the same problem - did you sort it? what was your remedy for it or you could not fix it.
Shane you Magneto you
I got the same problem with my kohler courage 20 but mines isn't back firing. It's just spinning and then the starter acts like it wants to hang up and then the fuse blows
Check coil
I think the problem with mine is it doesn’t want to cut the grass
The starter motor acts a capacitor
Hi from Gil take the kill wire off of the ignition coil water can get into the ignition switch and start shorting the coil circuit when engine speeds up also some of the non oem coils can be doing it spark doesn’t mean it’s ok test ohms to block from plug wire and block to kill tab Kill tab. To plug wire look for high ohms or open I had a eBay coil that would start and run backward
ccw the new coils have electronics built in them 20:35 20:35 advance retard that fail and will drive you nuts crank compression should be 60 psig check the resister in the spark plug or change it the compression release could be stuck Engaged
I think the problem is the hamaflam through the Dyno flow
It could be the turbo encabulator effecting the unilateral phase detrators.
Could be the chrome muffler bearing, or the flamigizer is completely shot or needs re calibrated.
Eureka!!
Hey
I had one Kawasaki engine that the camshaft teeth wore down and jumped time and backfired like yours.
Did you use lapping compound on the valves? It sounded like the intake valve wasn’t closing properly. Also when you take the head off you can put water in the intake and exhaust ports and check for leaks around the valves. It won’t hurt anything, if you’re worried about using water blast it out with some carburetor cleaner or something when you get done.
Anti- backfire solenoid on carborator on mine. Grind the stem down on the solinoid and put a fuel shutoff on gas line. Or buy a solinoid.
This may be to late for you but I had a briggs 20 hp do the same thing I reseated the valves and it worked for some reason because like yours they looked good go figure
I’m no expert but it sounds to me like the camshaft timing is off
try installing the coil upside down, tyrel has a video about this
I went through all the same things you have including lapping in the valves to no aval. I had spark and discounted that as the problem. I finally installed new coil and igniter and it solved the problem. would it be possible that the igniter even though new is still not functioning correctly?
Check your spark putting in line tester check your spark for it sounds like your coil is going out or is gone out also use a little hit of fogging oil or starting fluid it has to have done something probably the coil went out that's why it died or is going out it's a weak spark I just have to have fire and gas and it will run
I have the same mower with the same issues. Did you ever figure out what the problem was?
I know this is an old post, but did you ever find the problem? I have a Kawasaki fc540v doing the exact same thing. Had it running after changing igniter, fuel pump, carb, fuel shutoff solenoid, spark plug, fuel lines. Sat idle for a week, went to start and won’t fire and backfires very loudly.
I’m having the same issue and can’t figure it out new coil new spark igniter new regulator and no spark!
Look how hot it got because you didn’t have the cooling fan on look at the cylinder fins smoking you stuck the motor
Wow...I'm in the process of tuning and fixing up my JD GT275 with the FC540V. New hood and muffler. Then two days ago it did the same thing yours is doing...including a LOUD backfire. It actually ran well enough to make it around the block, but I could feel puffs of air coming out of the air filter inlet. I thought it needed a valve adjustment. Turned out it's a broken intake valve spring.
How did you remove the muffler? Need to replace front axle
Exact same thing here. Ran great yesterday....today a no start with a few LOUD backfires.
@@clutch5sp989 remove the valve cover and look for a broken valve spring. Easy to confirm or exclude this cause. I replaced the spring myself. I videoed the process, just haven’t had time to edit and post.
@@jedi_mapperp4073 OK...today I pulled the plug and checked having NO SPARK. Put a new plug in and had spark. WoW...nothing is supposed to be that easy to fix. I have never seen a plug go bad and not work.
@@jedi_mapperp4073 Also...when it cools off a little more here in TX, I'll pull the cover & check clearances. That and many other mech projects to tackle.
I just pull gas down off choke and it started up could be flooding
Definitely a timing issue. If the valves are not sticking and the valve springs are good, then maybe a camshaft to crank misalignment. Seems that would be quite odd from the way it just quit. That it fires out both the intake and the exhaust indicates either the timing keeps changing or both valves are sticky and are taking to long to close. Try some carb or parts cleaner in the valve guides if you think they are sticky. Make sure both springs are not broken. Other possibility is the timing gears are slipping. Those would be the mechanical things to look at. If I understand right there are no points. That means it must have a cam or crankshaft position sensor to control the timing, which then activates the ICM. Could be a bad sensor or loose screw/wire, or bad ICM. Those darn electronic ignition modules and sensors can be a pain. Give me the old points and condenser any day, much easier to tell if something is good or bad. I thought is was either a head gasket or slipped flywheel key. Had the latter happen to me once. I would start with the sensor and ICM, make sure it has ground good. I gather you have checked the timing and the spark after it quit running. Let us know how it goes. Would really like to see what the fix is. One other thing to check is that the battery voltage is not low, and the charging system is working. Some electronics do not work very well when the voltage is just a tad low. Maybe try running it with a charger hooked up, or a boost from a running vehicle, or good battery.
If customers won’t a China coil or electric part they have to buy it because I won’t to get paid when it fails
Does it have plastic crank gear???
Mine does that and ever time i pull the carb and clean it does good for about 4 or 5 starts then I have to do it again
What if the problem that you are having is NOT a mechanical problem but an electrical problem that is causing a mechanical error?🤔🤔🤔🤔
That has been bouncing around in my head...
That crossed my mind as well & have had issues in the past with a defective safety switch
My FC540V just recently did this. I'm still working on it but I do know if I pour just a little gas straight into the carburator, it will run for a few seconds, making me think it's not a timing issue.
What was the Fix ????
Would like to know what you found and what the fix was
Thank you
@@philliphall5198Sorry, didn't really think anyone read my comment. It turned out I had water in the gas. Pretty sure it was from the ethanol gas. I would much prefer to run straight gas in my mower but unfortunately there aren't any gas stations near me that sell straight gas. Anyways, I drained all of the old gas out and put in fresh and it ran just fine. Because of the issue I was having, I took the carb apart and cleaned it which it really needed.
check the cam it may be off ,,briggs are bad for that
I have a Craftsman with a Kohler Pro 16hp CV16S and when it's on idle it purrs like a kitten. Run it up to speed and it sounds like a jalopy! Keyway is perfect. Can't adjust valves. Pushrods are perfect. Switching out w a new carb and spark plug and we'll see how that goes.
Hey small engine diy. I'm currently worked on mine john deere 170, but I just can't get the flywheel off. Do you have any tips to get it off
Take a look at the John Deere series of videos. One of them shows me removing the flywheel.
Hopefully this will help you. UA-cam: "Why your lawn mower or generator backfires/misfires and how to fix." EASY. The presenter gives a great explanation. Back to the valves, he said it is 100% of the time the Valves also check the flywheel key, which also goes to the valves for timing.
I have the same problem with my DR Mower with a Kawasaki FC 420V.
The presenter said "Try tapping the intake valve with a soft mallet" to break loose the buildup on the valve. The additives in the gasoline build up around the Intake Valve. Hopefully this will resolve both of our problems since they appear to be the same. If it is the exhaust valve, it will normally have a bent stem.
I think you're on the right track with timing. I agree with what someone else said to watch the valves to get any hints on possible cam issues. If it's not the lobes then maybe the gear not lining up properly? But how does that become misaligned after running properly? Maybe broken teeth on cam gear? Definitely puzzling. Keep us posted
Plastic parts an agent grocery popular lately the manufacture try to cut cost at your expense
Try a new spark plug . Try the anti-backfire on the carburetor
Try a leak down test
I heard a mower in the back ground it was surging
Mine backfired from weak starter. Had starter rebuilt and problem solved
i have 2 mowers with the same engine , and 3 with the slightly larger fc540v engines . they're really particular about the plug . i've had them that would spark real well with plug out of engine , but wouldn't when plug was installed . swapped the plug from one that ran , and it would start then . usually though , the igniter has gone bad .
It the electronic shut off on you carborator
Did you find the problem??
Thanks for the video bought one yesterday of course it had no hood. It was raining on the way home now the symptoms are the same I have a fan on it let it dry out. We will see Update fan did the trick runs great
What did you find out to fix it ???
I’m dying to know, I love problem solving jobs and all the testing and stuff
Check your Valve Timing (camshaft) Compression test will be low
Cam lobes ???
I’m interested in finding out what the problem is and the solution.
did you find a solution to this yet
Be funny if just out of gas
she was also smoking a lot. Fuel in the oil? weak coil that craps out afetr it gets hot?
This john deere i have backfires so loud when it turns too much and i hate it i had a craftsman older but it started every time first try even after a long chrismas
Could be the spark plug
Leak down test, spark test, plug test, flywheel magnetic in correct place to fire on compression, valve movements, fuel pump test and starting fluid test
My 170 does this and I just feather the choke down and it fires up. So maybe full choke first few cycles and then when it starts puffing I back it off and it fires up. I’m no small engine mechanic but it’s been like this for 5 years since I bought it. Runs every summer like a top lol.
Here's what I think it is myself. It's one of three/3 things valve sticking& not seating properly.,or the lifters need readjusted again. It could be from A blower head gasket aswell to.
Did you ever find out why it kept back firing and wouldn't run ?
This happened to me I bought the lawn mower the breather cover was removed the the oil had water in it. I could get it to run but it kept backfiring ended up just switching the engine
Make me question the cam gear, seems to just free wheel like out of time
Same issue here
Still
No fix
Have even had it to a mechanic who has given up
Was a great ride on mower, just want to burn it to the ground
Wish I could get my hands on it...sounds like a challenge.👍👍
Or A damaged one instead it's A common problem on those aswell from using them.
i am stumped to
cam
That’s about how long a China coil last Lololo
BAD HEAD GASKET !! BURNING OIL TOO !!
I have a Craftsman LT 1000 giving me the same fits. It needs a top crank seal anyway so I guess I'm going in.
Good luck!
Try 4 through 8 thousandsance gap.
Try setting it at 4 to 8 thousandance gap for it's the valve man.
Why it would not back up
spun cam shaft?
Fuel pump replacement
Sir my 22hp backfires about every 3 seconds, would anyone know why?
Check valve lash
@@philliphall5198 ok thank you so much. I’ll try that.
Just wondering if you test spark with tester is it also intermittent ?
i first thought it was the fly wheel key also.
9th
Very strange
cam
cAM SHFT !!!
cam
cam
Cam
My brother gave me his JD 170 in 2003 and she's still running.
That's awesome. Although I rarely use it, it is tempting to keep it. It is actually a nice small tractor.
@@SmallEngineDIYI cut with it almost every weekend 1 to 1/1/2 acres. I thought of getting another JD sometime soon but I have wondered if there is anything comparable to this one today. I am in limbo. :)
I'm at 2:15 and my guess is you lost time .. backfiring is a tell tale sign of not being timed right .. probably loose timing chain/belt