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 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.

Hopefully this will help you. KZfaq: "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 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.

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

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

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 .

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

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 had one Kawasaki engine that the camshaft teeth wore down and jumped time and backfired like yours.

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 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.

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.

LOOK AT THE COIL WIRE FOR CRACKS IN WIRE TO THE PLUG. PLACE RAG UNDER WIRE TO TEST. IT MAY BE ARCING TO MOTOR.

try installing the coil upside down, tyrel has a video about this

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.

Attach the igniter to the dipstick for a better ground? Seen someone else do it and it worked🤷🏼‍♂️

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.

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.

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

I just pickup a JD 170 FC420v and it’s got that same problem, working on it now.

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 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?

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.

Just wondering if you test spark with tester is it also intermittent ?

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

Try setting it at 4 to 8 thousandance gap for it's the valve man.

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

i first thought it was the fly wheel key also.

I have the same mower with the same issues. Did you ever figure out what the problem was?

I have exactly the same problem - did you sort it? what was your remedy for it or you could not fix it.

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.

I just pull gas down off choke and it started up could be flooding

What did you find out to fix it ??? I’m dying to know, I love problem solving jobs and all the testing and stuff

Why it would not back up

I’m having the same issue and can’t figure it out new coil new spark igniter new regulator and no spark!

Try a new spark plug . Try the anti-backfire on the carburetor

My brother gave me his JD 170 in 2003 and she's still running.

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.

Did you ever find out why it kept back firing and wouldn't run ?

spun cam shaft?

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.

Did you find the problem??

Or A damaged one instead it's A common problem on those aswell from using them.

Try a leak down test

Check your Valve Timing (camshaft) Compression test will be low

It the electronic shut off on you carborator

I heard a mower in the back ground it was surging

Mine backfired from weak starter. Had starter rebuilt and problem solved

When u had the head off I noticed both valves were in, could u have a lose valve guide...

Cam lobes ???

she was also smoking a lot. Fuel in the oil? weak coil that craps out afetr it gets hot?

Check coil

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.

Make me question the cam gear, seems to just free wheel like out of time

i am stumped to

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

check the cam it may be off ,,briggs are bad for that

Could be the spark plug

The starter motor acts a capacitor

I’m interested in finding out what the problem is and the solution.

I’m no expert but it sounds to me like the camshaft timing is off

Look how hot it got because you didn’t have the cooling fan on look at the cylinder fins smoking you stuck the motor

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

I think the problem with mine is it doesn’t want to cut the grass

Fuel pump replacement

Try 4 through 8 thousandsance gap.

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

Cam

Hey

I think the problem is the hamaflam through the Dyno flow

BAD HEAD GASKET !! BURNING OIL TOO !!

cam

Sir my 22hp backfires about every 3 seconds, would anyone know why?

Very strange

What if the problem that you are having is NOT a mechanical problem but an electrical problem that is causing a mechanical error?🤔🤔🤔🤔

That’s about how long a China coil last Lololo

cAM SHFT !!!

Be funny if just out of gas

9th

cam

cam

cam