Very well done video. You did a great job, explained how to do and didn't drag it out for a hour. Thank you for posting this. A good buddy was having similar issues and I found your vid. This video was just what we needed to get his mower going. Thank you again good sir.
Great vid DPG... I looked through comments and although this was a year and a half ago, I didn't see anyone mention the sparks flying at 10:12 in the vid... bad ground or starter solenoid. I see your gas tank right above this. I felt I should say something but probably taken care of. You couldn't see it from sitting on the mower. Anyways, very well done.
Thank you. The sparks were from manually jumping the starter solenoid to start the lawnmower. That issue has been fixed, because it isn't a safe thing to do with gas that close as you said. But yeah, it's not something I recommend doing.
I believe this might be my problem. Its been surging a little over the past year. I ran out of gas in kind of a hard area to access, I have a weak leg due to sciatic nerve pain, so I had to get one of family members to help get gas in back into. So while it was sitting it got rained on heavy rain twice. When I cranked it, it started backfiring pretty bad, me thinking it got water in the system, I pulled the choke and ran it for about ten minutes at varying speeds as it would allow me to without choking down. After choking it, it got to where it ran pretty well but is still surging and popping slightly. When I choke it slightly it levels off and runs like brand new, that tells me plugs should be ok and your vacuum leak idea sounds like the culprit. Thanks so much for giving me the idea of what's going on. Its a Cub Cadet Zero turn 52" (I think) with twin cylinder Kawasaki engine. Happy Summer everyone.
I have a 1984 or 85-86 Murray 12/36 garden tractor 12hp Briggs Stratton I replaced ignition solenoid replaced fuel filter replaced the old school single piece carb and all it does is sit and turnover won’t fire but maybe once I cleaned the spark plug charged the battery and even rebuilt the starter nothing just sits and spins over
i have the same exact engine in my murray and it’s done this three times now so i’m finally giving up and putting a new engine in it, if anyone knows a way to fix this for good, please let me know so i don’t have to scrap a good engine
Hey I have the same exact engine except it's on the old 42" craftsman. I have spark, have fuel, carb is clean, valves are adjusted to 0.04, woodruff key " looks" fine not sheared or bent. When trying to start the engine it turns n turns on choke then backfires once really loud then repeats itself. Any tips on what it could be?
The fuel air adjustment could be off on your carburetor. I have a tough time diagnosing things without putting my hands on it, but I would try spraying some starting fluid in the intake to see what that does. If it starts and runs on starting fluid, I would focus on carburetor stuff. If it does the same thing you described, I would focus on spark, grounds, and the rest of the wiring. Other than that, a compression test may help determine the issue.
It could be that the choke lever cable is not adjusted correctly and the choke is not actually being turned on. Put starting fluid inside the mouth of carb and see if it does anything
Well I ended up having a bent pushrod on the intake side. Replaced it and no more backfire thru carb. Then realized the choke/ throttle assembly white plastic piece that the throttle cable attaches to had broke off. Fixed that from a parts mower. I can crank and start it now but only by pouring some gas down carb, so Im gonna take apart the carb again and clean it, if that doesn't fix it I have another carb on the parts mower I can use. Thank yal for the replies.
@@aronpayne1977 if you just want to get a Chinese carb you can, I don’t know what model engine your mower has but I think it has a Briggs and Stratton Intek. You can find a Chinese carb for like 12-20 dollars on eBay or Amazon, test your luck if you want.
you had any starting issues with that thing along the lines of intermittently not wanting to start by the key but will start everytime by jumping at the starter. ive tried replacing the solenoid, starter and key switch with no help
I haven't had that issue, but I would check all the grounds. Take the grounds all loose, clean the area, make sure there is solid metal contact, and then retighten them all.
@@deadpedalgarage6457 if i ever have my handle break off i got a extra big widebody murray handle it came off 1 i got rid of a long time ago i keep parts off of old mowers never no when u gonna need em
A plastic starting gear? Wow. I don't believe I have ever seen that before, but I am guessing that it is commonplace with some makers. Just another thing to look out for, when I buy me a new mower.
I actually did get a metal one a couple years ago and it was apparently sightly different than the plastic one and it destroyed the teeth on the flywheel ring gear. So I decided to stick with plastic as it's much easier to replace than the flywheel ring gear. I read somewhere that there where 2 different flywheels, one required a metal starter gear and one required plastic and they aren't interchangeable. But if it worked for you that's awesome.
I got a Murray just like it but cleaner it is so unreliable we put a bigger seat on it and repowered it from a Briggs & Stratton 12hp flat head engine which had a bad piston it was smokin like crazy so we repowered it 2 a Briggs & Stratton 14.5hp ohv engine
The briggs & stratton engine on this one has been very reliable other than the issue covered in this video. But man everything else that could go wrong has gone wrong; the battery wires melted (so I just rewired the whole thing), deck rusted badly (so i welded big patches in), had to replace every pulley and both spindles, the steering gear broke while driving it, and currently the rear end pulley shaft has wallowed out and slips the belt off. The list goes on, but it's cheap to repair and cuts decent, so....
DeadPedalGarage yea mine the engine is a good engine also but the hole mower is the problem it had the hole side taken out of the deck I tried weldin a piece metal on it but it didn’t work well but luckily I had a extra deck which came off another Murray sittin outside and just used it and it had burnt wire I took me a while 2 find and bad ground wires I’ve put several starter solinoids on it and it went out again I’m havin 2 jump it off ever time I get ready 2 mow until I get a new 1
I keep the battery disconnected when not in use and I went though a few starter solenoids before I decided to use the universal key (the big screwdriver) I used in this video lol.
backfiring is caused by a lack of enough fuel if you have adj usually on top of carb turn 1/4 turn counter clockwise this isa fuel jet to give more gas
Yep, you are right. Although, in this case the backfire was caused by the engine timing being off so the crankshaft and camshaft weren't communicating properly. Once the flywheel key was replaced, the engine ran perfectly with no carb adjustments needed. Thank you for watching and commenting.
@@jrx2662 It's a great lawn mower, engine works amazingly. I have replaced the key switch and solenoid since then. At the time i was being cheap and didnt want to invest much in an old lawn mower, but it has proved its value to me over time, so i try to keep it nicer now. It may get a full restore eventually, but I'm not sure if there will be a video
Have a 2005 Murray model 40500 also and the key didn't completely shear it cracked enough to throw off the ignition enough to cause occasional backfiring and would not restart when hot. Think it retarded the
Retarded the timing buy at least 5 to 10degrees. As the mower deck and transmission are belt driven I didn't think there would be enough torque to shear the key... Not so.
And at about $5 a piece those start to get expensive after going through a few. I ended up ordering a pack of 15 on ebay just so I'd have them around, and it was alot cheaper than buying them 1 at a time.
The starter gear,,, clean it with brake cleaner then hit it with spray lithium grease/oil.. similar to wd40.. so the gear floats .. your starter was filthy..
I'm trying to understand how a sheered key will cause backfire thru the carburetor. I wish you would have run the mower first before the repair so we could hear it before the repair. The starter issue is a result of the backfire so that doesn't really help us. Maybe if you put the starter issue in the description you would get more hits on this video. You have a nice speaking voice but you need to explain the cause and effect more. Just constructive criticism, other than that I really like your videos.
The key holds the flywheel in place. The flywheel controls ignition timing (when spark happens). So when the key breaks, the engine turns faster than the flywheel, so it will sometimes spark when the intake valves are open causing a back fire through the carb. I honestly see the starter problem as another clue to if someone has this same issue. In hindsight I wish I would have included a clip of the problem as well. I really appreciate the feedback, my channel is very small so it helps me alot.
Magnets on the flywheel charge the coil that fire the plug. With the sheered key the timing is now off and most likely firing too soon. This is probably happening just before the intake valve is fully closed and thus burning fuel pops back through the carburetor. Also with this timing too advanced, the engine is kicking back while trying to start and damaging the plastic gear on the starter.
This was a quick simple video that was never meant to address every no start/backfire issue there is. It was meant to cover an easily overlooked issue (the flywheel key). If your flywheel key ever shears like mine did, you'll feel better that you wasted this 10 minutes. In hindsight I do wish I would have included a recording of what mine was doing before I fixed it. Thank you for your time and comment.
Very well done video. You did a great job, explained how to do and didn't drag it out for a hour. Thank you for posting this. A good buddy was having similar issues and I found your vid. This video was just what we needed to get his mower going. Thank you again good sir.
Thanks. I'm happy it was able to help your friend.
Great vid DPG... I looked through comments and although this was a year and a half ago, I didn't see anyone mention the sparks flying at 10:12 in the vid... bad ground or starter solenoid. I see your gas tank right above this. I felt I should say something but probably taken care of. You couldn't see it from sitting on the mower. Anyways, very well done.
Thank you. The sparks were from manually jumping the starter solenoid to start the lawnmower. That issue has been fixed, because it isn't a safe thing to do with gas that close as you said. But yeah, it's not something I recommend doing.
I believe this might be my problem. Its been surging a little over the past year. I ran out of gas in kind of a hard area to access, I have a weak leg due to sciatic nerve pain, so I had to get one of family members to help get gas in back into. So while it was sitting it got rained on heavy rain twice. When I cranked it, it started backfiring pretty bad, me thinking it got water in the system, I pulled the choke and ran it for about ten minutes at varying speeds as it would allow me to without choking down. After choking it, it got to where it ran pretty well but is still surging and popping slightly. When I choke it slightly it levels off and runs like brand new, that tells me plugs should be ok and your vacuum leak idea sounds like the culprit. Thanks so much for giving me the idea of what's going on. Its a Cub Cadet Zero turn 52" (I think) with twin cylinder Kawasaki engine. Happy Summer everyone.
Thank you mine was running fine and I could not figure out what was wrong thank you I had the same problem
I have a 1984 or 85-86 Murray 12/36 garden tractor 12hp Briggs Stratton I replaced ignition solenoid replaced fuel filter replaced the old school single piece carb and all it does is sit and turnover won’t fire but maybe once I cleaned the spark plug charged the battery and even rebuilt the starter nothing just sits and spins over
i had that woodruf key sheer on an old outboard mtr .rare but it does happen
i have the same exact engine in my murray and it’s done this three times now so i’m finally giving up and putting a new engine in it, if anyone knows a way to fix this for good, please let me know so i don’t have to scrap a good engine
Make sure it's torqued at a 100 lbs. If it's not it will shear again.
good job sir
Thanks.
Hey I have the same exact engine except it's on the old 42" craftsman. I have spark, have fuel, carb is clean, valves are adjusted to 0.04, woodruff key " looks" fine not sheared or bent. When trying to start the engine it turns n turns on choke then backfires once really loud then repeats itself. Any tips on what it could be?
The fuel air adjustment could be off on your carburetor. I have a tough time diagnosing things without putting my hands on it, but I would try spraying some starting fluid in the intake to see what that does. If it starts and runs on starting fluid, I would focus on carburetor stuff. If it does the same thing you described, I would focus on spark, grounds, and the rest of the wiring. Other than that, a compression test may help determine the issue.
It could be that the choke lever cable is not adjusted correctly and the choke is not actually being turned on. Put starting fluid inside the mouth of carb and see if it does anything
Well I ended up having a bent pushrod on the intake side. Replaced it and no more backfire thru carb. Then realized the choke/ throttle assembly white plastic piece that the throttle cable attaches to had broke off. Fixed that from a parts mower. I can crank and start it now but only by pouring some gas down carb, so Im gonna take apart the carb again and clean it, if that doesn't fix it I have another carb on the parts mower I can use. Thank yal for the replies.
@@aronpayne1977 if you just want to get a Chinese carb you can, I don’t know what model engine your mower has but I think it has a Briggs and Stratton Intek. You can find a Chinese carb for like 12-20 dollars on eBay or Amazon, test your luck if you want.
you had any starting issues with that thing along the lines of intermittently not wanting to start by the key but will start everytime by jumping at the starter. ive tried replacing the solenoid, starter and key switch with no help
I haven't had that issue, but I would check all the grounds. Take the grounds all loose, clean the area, make sure there is solid metal contact, and then retighten them all.
how do u engage the mower deck with handle broke off
Like an idiot, lol. It's not something I recommend anyone doing or want to teach anyone. But I have replaced the handle since this video.
@@deadpedalgarage6457 if i ever have my handle break off i got a extra big widebody murray handle it came off 1 i got rid of a long time ago i keep parts off of old mowers never no when u gonna need em
A plastic starting gear?
Wow. I don't believe I have ever seen that before, but I am guessing that it is commonplace with some makers.
Just another thing to look out for, when I buy me a new mower.
most briggs engines have plastic starter gears, its pretty rare to find a steel one
i had one that would shear the key soon as it started hit the bolt with a air wrench and no problems since
Those little plastic starter ring is a pain mine breaks often so I had to get a aluminum one .
I actually did get a metal one a couple years ago and it was apparently sightly different than the plastic one and it destroyed the teeth on the flywheel ring gear. So I decided to stick with plastic as it's much easier to replace than the flywheel ring gear. I read somewhere that there where 2 different flywheels, one required a metal starter gear and one required plastic and they aren't interchangeable. But if it worked for you that's awesome.
I got a Murray just like it but cleaner it is so unreliable we put a bigger seat on it and repowered it from a Briggs & Stratton 12hp flat head engine which had a bad piston it was smokin like crazy so we repowered it 2 a Briggs & Stratton 14.5hp ohv engine
The briggs & stratton engine on this one has been very reliable other than the issue covered in this video. But man everything else that could go wrong has gone wrong; the battery wires melted (so I just rewired the whole thing), deck rusted badly (so i welded big patches in), had to replace every pulley and both spindles, the steering gear broke while driving it, and currently the rear end pulley shaft has wallowed out and slips the belt off. The list goes on, but it's cheap to repair and cuts decent, so....
DeadPedalGarage yea mine the engine is a good engine also but the hole mower is the problem it had the hole side taken out of the deck I tried weldin a piece metal on it but it didn’t work well but luckily I had a extra deck which came off another Murray sittin outside and just used it and it had burnt wire I took me a while 2 find and bad ground wires I’ve put several starter solinoids on it and it went out again I’m havin 2 jump it off ever time I get ready 2 mow until I get a new 1
I keep the battery disconnected when not in use and I went though a few starter solenoids before I decided to use the universal key (the big screwdriver) I used in this video lol.
backfiring is caused by a lack of enough fuel if you have adj usually on top of carb turn 1/4 turn counter clockwise this isa fuel jet to give more gas
Yep, you are right. Although, in this case the backfire was caused by the engine timing being off so the crankshaft and camshaft weren't communicating properly. Once the flywheel key was replaced, the engine ran perfectly with no carb adjustments needed. Thank you for watching and commenting.
the engine sound nice, why not just buy a new ignition switch key and a starter solenoid?
@@jrx2662 It's a great lawn mower, engine works amazingly. I have replaced the key switch and solenoid since then. At the time i was being cheap and didnt want to invest much in an old lawn mower, but it has proved its value to me over time, so i try to keep it nicer now. It may get a full restore eventually, but I'm not sure if there will be a video
Have a 2005 Murray model 40500 also and the key didn't completely shear it cracked enough to throw off the ignition enough to cause occasional backfiring and would not restart when hot. Think it retarded the
Retarded the timing buy at least 5 to 10degrees. As the mower deck and transmission are belt driven I didn't think there would be enough torque to shear the key... Not so.
Something so simple can really cause you to scratch your head wondering what is going on. Lol.
lol! good one! cool!
The starter gear just broke on mine today after I tried jumpin it off
And at about $5 a piece those start to get expensive after going through a few. I ended up ordering a pack of 15 on ebay just so I'd have them around, and it was alot cheaper than buying them 1 at a time.
DeadPedalGarage I just used the starter off the old flat head engine which used 2 be on it and it worked it started up
The starter gear,,, clean it with brake cleaner then hit it with spray lithium grease/oil.. similar to wd40.. so the gear floats .. your starter was filthy..
Thanks, I'll give that a try. That whole lawn mower is filthy lol.
I'm trying to understand how a sheered key will cause backfire thru the carburetor. I wish you would have run the mower first before the repair so we could hear it before the repair.
The starter issue is a result of the backfire so that doesn't really help us. Maybe if you put the starter issue in the description you would get more hits on this video.
You have a nice speaking voice but you need to explain the cause and effect more.
Just constructive criticism, other than that I really like your videos.
The key holds the flywheel in place. The flywheel controls ignition timing (when spark happens). So when the key breaks, the engine turns faster than the flywheel, so it will sometimes spark when the intake valves are open causing a back fire through the carb. I honestly see the starter problem as another clue to if someone has this same issue.
In hindsight I wish I would have included a clip of the problem as well.
I really appreciate the feedback, my channel is very small so it helps me alot.
Magnets on the flywheel charge the coil that fire the plug. With the sheered key the timing is now off and most likely firing too soon. This is probably happening just before the intake valve is fully closed and thus burning fuel pops back through the carburetor. Also with this timing too advanced, the engine is kicking back while trying to start and damaging the plastic gear on the starter.
This video didn’t address any of my issues and didn’t address any backfiring issues . That’s 10 minutes of my life I’ll never get back
This was a quick simple video that was never meant to address every no start/backfire issue there is. It was meant to cover an easily overlooked issue (the flywheel key). If your flywheel key ever shears like mine did, you'll feel better that you wasted this 10 minutes. In hindsight I do wish I would have included a recording of what mine was doing before I fixed it.
Thank you for your time and comment.