LAPPING THE VALVES IN WILL take care of this problem, they are not seating properly, for me it removed all the spitting and popping, cracking that i first believed it to be a water issue, mine is 20 years old it is a tecumseh 13.5 HP . As i sit here looking at these engines you must agree it is a modern miracle with all that goes on inside a combustion engine , thousands of explosions, over and over again that these things even work for one single day. Imagine how smart and clever the man was to invent such an engineering piese of work to allow the one in front of me now to do this twenty years 6 months a year every week . THIS proves that changing the oil every 50 hours WORKS, IT ONLY HOLDS A SINGLE QUART FROM EMPTY. Now retired physician 45 years practicing, nothing brings me more pleasure than working on small engines. thank you great video.

I had the same issue with backfiring through the intake on a B&S engine on a 1998 Husqvarna Swedish Rider. My issue was caused by carbon buildup preventing the exhaust and intake valves from seating properly. The way I identified the problem was by pressurizing the cylinder while just past TDC (to ensure the pressure relief was closed) and was able to hear the air escaping past the exhaust and intake valves by listening to to exhaust pipe and intake manifold . Lapping the valves fixed the issue. Also, running an engine with that condition on the exhaust valve causes the exhaust manifold to glow cherry red. Thanks for the video I enjoyed watching!

I watch your video for 45min ..I got bored and i,went to sleep @4:15Am....i was the cause of that..I was looking for one other PROBLEM FIXTURE in MY video.. @the very very very last end 4:40AM...I SKIP AROUND. SUDDENLY MY LAWNMOWER STARTED UP AT LAST FROM YOUR VIDEO. I COULD HAVE CRYED. INSTEAD I THANK GOD FOR GOD MAKING IT POSSIBLE FOR ME TO WATCH YOUR VIDEO..AFTER WATHING OTHER VIDEOS THAT WASN'T THE ANSWER... I AM PROUD TO SAY IT WAS THE LAST ONE..THANK YOU CUZ IT WAS THE LAST ONE ...IT WAS WELL EXPLAINED I WOKE UP @5:30AM AND SAID I DID IT, OR DID I.

Hi my friend good video. I’m sure it will run ok when serviced. Good on you for investing the problems. Will stay tuned

Change fluids, check compression, clean coil and regap, clean carb, Adjust valve clearances.

Like the green look on this mower

looks like the valve guild seal has moved up.

Nice work.

I'd figure the backfire/popback is due to the intake valve not opening and closing at the right time, or not being sealed when closed. It could be the cam isn't timed properly, or the seat isn't sealing the valve properly, hence air/fuel is getting pushed out the intake when combusted. And that could be a bad seat angle, bent valve, or carbon buildup like you noticed.

I work on a lot of vintage riding mowers, And the one rule i can never bypass is, Always remove all fluids from the machine, And replace. So far i have a 100% success ratio at getting the engines running, And it's mostly due to this rule. You would not believe the crud that I've found in the crank cases of the ones that were left outdoors. But by changing the oil, I am able to determine what kind of shape the crankcase is in, And whether i need to open it or not.

First thing I do is check valves adjustment and check for bumb

Double check your valves. From the looks of your video, the top val v e is the exhaust valve and the bottom one is the intake valve. Remember the aluminum push rod is always the intake valve

never seen a head where the intake valve is smaller than the exhaust valve !!! th e intake valve has the alum. push rod the exhaust has the steel push rod !!!

Nice video 👍🏼

Good Job Ellis .

Man U Got Them For a Steal , Good On You. I need a Few more Cheapies Like That

Those craftsman’s are very reliable the Ayp is probably the easiest system to work with.

Nice, but you shoulda cleaned the fly wheel magneato assembly carefully, and the same with inner coil assembly where it's mates with the flywheel, it is very very dirty and rusty. Sure glad it sparked👍.

working on the same kind of mower, LT1000. Got some issues idling and flames spitting back through the carb, havent been able to open the carb up because of stuck bolts.

You have your valves mixed up! Exhaust on top, intake on bottom with aluminium pushrod.

what did you do to the valves?

Good job showing, I am working on the same mower 2009 craftsman with a21.0 braggs called a platinum are they ok let me no. PS have a good one

Great video. I have a Craftsman 18 HP LT1000 Intek. And it was dieseling and I shut it off. It started then dieseled again and shut off and now wont start. Turns over and every now and then it will backfire out of the carb and near the exhaust. Changed Spark plug, carb, coil, engine oil, adjusted valves, checked flywheel key. Even tried starting fluid but wont start. It did hit some roots about a month ago and it stopped, I had to change the blade but started up and ran OK at that time and recently. Not sure what do do now. Ideas?

Where did you learn the serial number codes?

Compression test, could revealed a problem

Guys I got a craftman tractor with a 24 HP engine , I change the starter battery and it wont start rapidly, I put on the charger and then it runs fast some times , if I take off one spark plug , it runs good and get on with one spark , what’shappens ?

How does someone run the tread off a riding mower's tires? I've never seen that before. I get dry rot, or a flat, but worn tread?!

what model is your electric impact drill / tool? looks like a good one i'll have to check specs on. btw, i wouldn't run that on full throttle like that just sitting there with no blades turning and no air moving over the engine. There's a lot of violent things happening inside a small engine, and then mix in heat and you have a recipe for disaster (head gasket, premature engine wear, etc.) just a little tip. keep up the good work!

Ellis i have the same problem with my engine but mine fills up the valve room with oil. can you help?

I think you have a safety switch grounding out somewhere. Seat are blades

Not a good idea to run engine at full throttle for any length of time, without a load on it. Start it and bring it down to close to idle until it warms up a tad, then 3/4 throttle to get going and engage blades then you can go to full throttle.. Running wide open for any length of time without a load is how engines get ruined or things break.. One of the worst things for these small engines is the automatic choke.. Full throttle and choke on a cold engine is really bad, get it off choke and slower RPM as soon as possible and let the engine warm up and get oil supply.. Best thing to do is run a separate choke cable.. and start the engine at 1/2 or less throttle.. You may have saved yourself some time by putting some gas in the spark plug hole first (best is 2 cycle mix - gets oil to cylinder wall, piston and rings right away), if it starts and runs then you, move to the next step (carb will be 95% of the problems).. Always do step 1, Step 1 - check the oil level (too high, will hydro lock the engine - gas may have leaked into crankcase past needle and seat), Step 2 - check for spark, Step 3 - put some gas in the spark plug hole to see if it starts and runs.. Then go from there - carb clean, valve adjustment, blown head gasket etc..

Check to see if the valve seats have moved. If the engine overheat the valve seat will move and be knocked back into or pressed back into the head.

thought you had to step on the clutch to start it

Did you clean gas tank before trying to start that shit looked awful

I run B12 in fuel tank and just let it run to remove some excess carbon

Most likely it has been apart, and maybe the person didn't time it correctly, as in line up the dots.... If the flywheel key is ok, then the timing problem is internal..... But nice job man.

Spray it in there as you’re turning it over

I'm having the same exact issue with my Briggs & Stratton 18.5 hp Intek engine. Backfire from muffler and air intake (flames). Flywheel key is intact.

The top valve is the exhaust valve...

The top valve is not intake valve

Ok ok get on with pulling the head Dang boy 😅

Needs valve adjustment. Firing on an open intake valve

If it was mine I’d pull the head and clean it up plus lab or grind valves For sure if I was going to sale it

Beware of creepy crawlers. Whenever I repair old stuff I'm looking where I put my hands. Have bug spray on hand

Clean mower first, Change oil & filter , clean tank and put new gas in , clean carb inside & out , change plug , then go internal . 25 minutes I neve get back I skipped alot after I seen you never even cleaned it or changed the fuel and oil.

Valve stuck open Run leak down test Carbon up engine and has often broke piston ring gland

Old gas has bad octane also burns dirty ,a lot of carbon . always use fresh gas .solves a lot of problems .

On some engines if they have a pressed in valve guides the valve guide can be forced out of its proper location forcing the valve to not close ,the other scratch your head it won't run and it backfires "but" flywheel key is fine ,but it still is a likely timing issue ,, impacting some engines is the illusive "Cam gear has broken loose and spun on the cam shaft throwing the valve timing way off. "spun" cam gear timing,.For engines that the starter wont spin due to high compression , look out for a broken compression release mechanism on the cam as well after ensuring the valves are adjusted correctly. kzfaq.info/get/bejne/sMqohMWf1NO-Z5c.html Valve guide example,, kzfaq.info/get/bejne/a92AidqlntOskoU.html

Well.you went to.the right person for help. Plus the gas is the first thing to check.because of the ethanol great that she running like she should see you.latet young man

Shoot..I wanted to see how to exactly remove parts to get to key but you skipped right over it..good video othereise

Plug is dead maybe or timing Look at blades for serious damage

So what the hell you do to getting from popping

Bent pushrod check that

What the price?

Now you’re full time you need to be on lookout for a old valve machine… It’s very fast and reliable way to rework the heads😊

Your about the luckiest little shit I've ever seen on getting these motors running without putting a lot if money into it good job

When you had the valve cover off ,the valve you were pointing out that had the residue around it was the exhaust valve, also you only showed one valve out of the head, that one was the exhaust valve again.

😂❤️😂❤️😂❤️

Ellis what you are calling the intake valve is the exhaust valves silly

usually back firuing is a sign the eng. is starving for gas there is an adjust ment in top of carb with a small flat blade screwdriver turn 1/4 turn counter clockwise if start up better try very slowly turning that same screw till it about normal this may help if it dont help turn back to about where it was go to plan B make these ajd at idle if you can

EXSULT VALVE

Way to much talking. Use a fuel bottle like Must I does. Got bored and have to move on.