That abrasive reminded me of the service bulletin that Briggs sent out decades ago warning dealers not to sand blast spark plugs because they had found that some sand would sometimes get stuck inside the spark plug, and come out during operation, then scratch up the cylinder wall. I guess the sand would get trapped in the piston rings and cut away the metal. You don't need a very deep scratch to lose a lot of compression. Spark plugs were expensive until they started importing them from Asia. You had to change them since the electrodes burned away a lot quicker than they do today, with metals like platinum and iridium used as electrode tips. You would think that a 50,000 volt spark would soon erode any metal surface. For decades, sand blasting plugs 'clean' to get the carbon off of them was routine.
well he's actually culling through engines trying to re-power a decent deck. Had a B&S Sprint non-Q engine, used too much oil. It ran but I just pulled it & tossed the whole thing. Needed at least two hours of labor every season, over & above typical blade sharpening, oil change, air filter cleaning. Not worth it when there are better engines out there with more power & greater dependability. Problem is the Quantum when running is the single best flathead available, any year, any model. Not made anymore. So I'd hesitate to toss any Q without picking its bones for any & all parts. I would love to see an autopsy of that Q engine he was setting up in Part III. Guess the rings are shot or the camshaft lobe(s) are slipping or something.
Just a couple of things. First. I love this season 1 of thr snapper series. Second, the very next thing i would have done is a test on a known good engine to test my testing equipment. Third, i keep a temporary tank setup all the time. Put some gas to it and spin it over with a drill. It doesn't mean that it will start with a recoil but definitely rules out a zero compression issue.
Tom, this is my first visit to your channel. I have not seen any of your other efforts to repair this engine. I had a problem a while ago that never occurred to me before I saw it myself. Some of those engines have a plastic bonded camshaft drive gear that can come loose. It looks completely normal, but it has slipped timing and will not run. Have you looked at your camshaft? Is it a plastic geared unit? Have you ever seen a plastic camshaft? Both intake & exhaust should be closed at top dead center, but they should be 100% closed much before and after TDC as well. TDC is not the only answer, 90 + and - TDC should be closed as well. If your cam timing is wrong it will not seal the valves when necessary and a slipped plastic drive gear could be causing your grief. Good Luck on your repair
I have a mower with the OHV version of the second engine in it. I had a weird problem that had me stumped for a minute with that engine. this mower belonged to my grandfather, and I got it a few years ago. It had been sitting in his back yard for several years before I got it. I got it running again a few years back, and started using it regularly. A couple of years ago, I winterized it and put it up for the winter in my shop. When I pulled it out the next Spring, it had no spark. After doing a lot of troubleshooting and getting irritated, I eventually found that the kill switch had failed. I didn't even know it was possible for that Briggs kill switch to fail. I cleaned it up spotless, and it still wouldn't work. It just failed sitting indoors over the winter. I actually picked up another one a couple of months ago with the same issue, though I was able to get that one working again. I come across some strange issues sometimes. lol
Does the crankcase vent to the air cleaner box, or to the intake manifold ??? If so, remove that tube and check to see if your escaping air, during leak down testing, is coming from that disconnected tube. If so, the rings are bad. And you have done the valve job twice, for nothing. I did enjoy seeing the valve job, though.....especially the spring compressor tool !!!
And beyond the leak down test, how much compression could you generate on a compression gauge, while hand cranking a small engine equipped with an internal compression release....????
Something isn't making sense here. I'm certainly not an expert by any means, but unless it has a stuck ring, I don't see how the rings could be the issue with that engine. It has zero compression. If it was simply worn rings, the engine would have quit running long before it got bad enough to have no compression. Break that engine down again and take a look at the piston. You probably have a stuck ring or two from the engine sitting. The engine is probably okay. Whether I am right or totally wrong, I would like to find out what it is.
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
Toooom Doooobyyyy! Good Lord, Tom! Hopefully, 5TH time's a charm! Good luck! God bless.
Tom you’re definitely keeping us in suspense. 😂😂 👍👍👍
Gr8 vid. Not many on RUclips to this detail on doing a valve job on a flathead lawnmower
That abrasive reminded me of the service bulletin that Briggs sent out decades ago warning dealers not to sand blast spark plugs because they had found that some sand would sometimes get stuck inside the spark plug, and come out during operation, then scratch up the cylinder wall. I guess the sand would get trapped in the piston rings and cut away the metal. You don't need a very deep scratch to lose a lot of compression.
Spark plugs were expensive until they started importing them from Asia. You had to change them since the electrodes burned away a lot quicker than they do today, with metals like platinum and iridium used as electrode tips. You would think that a 50,000 volt spark would soon erode any metal surface. For decades, sand blasting plugs 'clean' to get the carbon off of them was routine.
Tom, Steve’s Small Engine Saloon just put out a video about compression testers. Check it out.
Just buy otc stuff and it’s correct
what is otc? a brand?
Yes 👍
@@TomDobyMowerRepair
It sells at NAPA. Good tools.
Way more patience than I would have it been junked long time ago
well he's actually culling through engines trying to re-power a decent deck.
Had a B&S Sprint non-Q engine, used too much oil. It ran but I just pulled it & tossed the whole thing. Needed at least two hours of labor every season, over & above typical blade sharpening, oil change, air filter cleaning. Not worth it when there are better engines out there with more power & greater dependability. Problem is the Quantum when running is the single best flathead available, any year, any model. Not made anymore. So I'd hesitate to toss any Q without picking its bones for any & all parts.
I would love to see an autopsy of that Q engine he was setting up in Part III. Guess the rings are shot or the camshaft lobe(s) are slipping or something.
did a video on that particular engine today! its going on a toro deck hehehe
Come on Tom, I haven't seen a carb cleaning video in a few days now, I'm starting to get the shakes. 🤣🤣
Come on Tom, let's GET IT! 😆
Just a couple of things. First. I love this season 1 of thr snapper series. Second, the very next thing i would have done is a test on a known good engine to test my testing equipment. Third, i keep a temporary tank setup all the time. Put some gas to it and spin it over with a drill. It doesn't mean that it will start with a recoil but definitely rules out a zero compression issue.
you'll see i used 6 different compression testers
It’s the top of the line for tools and equipment 😊, I got a shop full of it
@@philliphall5198 thought you were trying to get me to buy over the counter meds
@ lolol
No don’t take no meds , just eat right
Tom, this is my first visit to your channel. I have not seen any of your other efforts to repair this engine. I had a problem a while ago that never occurred to me before I saw it myself. Some of those engines have a plastic bonded camshaft drive gear that can come loose. It looks completely normal, but it has slipped timing and will not run. Have you looked at your camshaft? Is it a plastic geared unit? Have you ever seen a plastic camshaft? Both intake & exhaust should be closed at top dead center, but they should be 100% closed much before and after TDC as well. TDC is not the only answer, 90 + and - TDC should be closed as well. If your cam timing is wrong it will not seal the valves when necessary and a slipped plastic drive gear could be causing your grief. Good Luck on your repair
yea watch the whole series, think it will explain everything!
Part 5 coming soon to a RUclips video near you.
great vlog on channel
I have a mower with the OHV version of the second engine in it. I had a weird problem that had me stumped for a minute with that engine. this mower belonged to my grandfather, and I got it a few years ago. It had been sitting in his back yard for several years before I got it. I got it running again a few years back, and started using it regularly. A couple of years ago, I winterized it and put it up for the winter in my shop. When I pulled it out the next Spring, it had no spark. After doing a lot of troubleshooting and getting irritated, I eventually found that the kill switch had failed. I didn't even know it was possible for that Briggs kill switch to fail. I cleaned it up spotless, and it still wouldn't work. It just failed sitting indoors over the winter. I actually picked up another one a couple of months ago with the same issue, though I was able to get that one working again. I come across some strange issues sometimes. lol
Think it time take dip stick out and push a other mower under and put dip stick back lol
Capt-N the engine can't take anymore.. LMAO
Does the crankcase vent to the air cleaner box, or to the intake manifold ??? If so, remove that tube and check to see if your escaping air, during leak down testing, is coming from that disconnected tube. If so, the rings are bad. And you have done the valve job twice, for nothing. I did enjoy seeing the valve job, though.....especially the spring compressor tool !!!
it vents to the area of the valve springs, the intake tube sits behind the valve seat so its completely isolated, that couldnt be it
And beyond the leak down test, how much compression could you generate on a compression gauge, while hand cranking a small engine equipped with an internal compression release....????
it won't release the compression to zero
I'm biting my nails man.... Lol
Tom another set of eyes might help. Maybe your missing something
you spend so many hours you start to miss things for sure
5Th times a charm.
😂
Something isn't making sense here. I'm certainly not an expert by any means, but unless it has a stuck ring, I don't see how the rings could be the issue with that engine. It has zero compression. If it was simply worn rings, the engine would have quit running long before it got bad enough to have no compression. Break that engine down again and take a look at the piston. You probably have a stuck ring or two from the engine sitting. The engine is probably okay. Whether I am right or totally wrong, I would like to find out what it is.
stay tuuuuuned haha