I'm taking an internal combustion engine class in college for an ME degree (senior year). Your explanation cleared up more in 5 minutes than an hours worth of textbook digging and google searching could. appreciate ya!
I'm 55 and I have wondered for years how the decompression mechanism works - you would not believe how happy I am to finally understand how it works! - Huge thanks for the video
now I finally understand what this decompression valve is on my 84 Suzuki LT185. I've looked all over the net and this is the most detailed easily understood explanation of this topic. Thanks!
Thanks so much. 2:33 was the hit me over the head ah ha moment for me. I heard it explained many time but, your visual brought it to light for me. Thanks again.
Been a machine for 35 years that is a verry good explication of how compression release works and i did know B/S had that in the small engines. thank you J C
Great information here. I adjusted the valves on a tiller that was an absolute bear to start, and voila. I actually verified the spark plug was tight it pulled and started so easy!! Considering it would yank your shoulder off of your body prior, I was pretty excited.
I have a Kawasaki Fc420v, trying to start it, I would have my arm ripped out of its socket. I then realized that the valves needed adjustment. It was that mechanism that was giving me the problem! Thank You for the great video!
Well damn, I knew how the decompression worked on a big chainsaw but could not figure out how it worked on a larger mower engine... now I understand what people meant by "the bump". Thank you!
Great explanation and demo. I have a vanguard 18hp that runs perfectly and strong, but if it doesn't start on the first pull, then the second stroke you feel on the second pull can break the cord. Then it starts every time at least on that third pull if it didn't on the first. Hoping it's this, and I can live with it. Nice to know how they work now though.
I am working for the first time on a Briggstratton CR 950 and was confused with the exhaust valve because it opens a little bit and it sucked a little air and then opens all the way and discharge. Thanks for this video I learned way.thanks
Thanks for this video. A Gorilla couldn't pull the start cord on my new Honda engine. The service manager had me draining oil and pully the sparkplug before I came across your video. One hit with my rubber mallet apparently dislodged a stuck relief and the engine started with one pull. The engine was shipped to me and I suspect the relief moved. The engine has been starting easily since. Thank you very much!
I have the same Intek 18.5 HP engine that is in the video. Adjusted the valves at top dead center, and the engine was hard to start. Had to rotate engine by hand just past the compression stroke, and then it would start, and it ran good. Adjusted the valves again at 1/4 inch past TDC, and bam it cranked right up every time. That 1/4 inch was the difference between hard to start, and cranking right up like it's supposed to do. I reckon the 1/4 inch past TDC has something to do with the compression release.
That same thing happened with my Briggs V-twin 22HP. Re-adjusted the valves by going 1/4 inch past TDC and worked. Started right up no problem. It won't crank past the compression stroke before doing this. Thanks snippits75
You probably dont care at all but does anybody know a method to log back into an instagram account? I stupidly forgot the login password. I would appreciate any help you can give me!
@Magnus Clay I really appreciate your reply. I found the site thru google and I'm waiting for the hacking stuff atm. I see it takes a while so I will reply here later with my results.
I knew the exhaust was opening early but did not know why, you told me and it was so simple once you explained, many thanks now subscribed. PS I'm was a body panel man, not a mechanic until retirement.
Great explanation! Have you done a video explaining how adjusting the valves works to solve this problem when the compression release is working normally?
Thanks, when I putting my Honda GXV140 crank shaft/timing gear back together I couldn't figure out the temporary hang up as I was turning the crank. Now I know.
Some do some don’t you would have to look up your engines specifications to be able to tell but you can just pull the valve cover and rotate the engine over and it should open the valve slightly right before top dead center
Good video now I understand a little bit more about how compression release works, I've been having the worst time with too much compression and in my riding mowers for the last couple of seasons. I keep readjusting the valves and they will run normal for a while but it doesn't last and I'm thinking it's got to be something else...
Thank you for your timer brother, My mower and i watched a lot of compression videos trying to fix it but this was the first showing what the hell makes it not work in the first place. Hopefully i can get it to run now that I know how it works
Great explanation MM1, and perfect timing have one in the shop now that I suspect has a bad compression release im going to show this video to my customer to help explain whats going on.
okay, thanks. I have a Coleman Powermate 6875 that takes about 35 pulls to start. Once it's starts it runs great. But I noticed it gets easy to pull just before it's going to start. So this sounds like the compression release to me. Thanks!
I love it. Short, straight to the point explained simply. Why some cams have no compression release? Is it for racing? Just got in to small engines not too long ago.
Great. I have an old sears mower, probably 20 years old. 5.5 tecumseth i belive. It does appear to have that compression release. I had it appart to fix a broken camshaft. ( yes i tig brazed it back together. ) i thought it might be something else. But when you described how it stops, it makes sence. Ill look into to it. Thank you
It` a nice tutorial! Can you tell whether smaller Briggs engines have the same system, please? We have 7.25HP on our mower. According to its parts list, camshaft5 is made of green in color plastic (excluding its axle only :) Thank you
Excellent! clearly explained how an automatic compression release works. I have a newbie question, why is there a need to release compression at that very moment and for a given angle? If someone posts an answer I will greatly appreciate it.
Its sole purpose is to make the engine easier to crank. So you can use a smaller battery, starter, etc. while at the same time running a higher compression engine which will have more power/efficiency.
Question sir, my 18 horse briggs,, my compression release is not broken, will worn lobes on cam cause me to have to adjust the valves every time I mow?
Great video, and very clear explanation as to how that slinger lifts the valve....Thanks! May I ask - in you experience, how far out of adjustment would the valves have to be, to make it hard to start? If they were out 0.001-0.002" would that make it hard to start?
i have a 12hp briggs and just pulled out the cam . this engine ran ok full speed but like crap idle or hi idle . what i found is the intake valve was being held open thru the entire compression stroke just slightly but on top dead center it would close tight and clearance is .005 . is the cam lobe ground wrong ?
I got a question sir :) On a CG200 motorcycle engine will an aftermarket cam gear with decomp help relieve a kickback problem on my kick starter ? I gotta say my right leg sometimes hurt when my damn motorcycle kick starter kick's back 😵💫
I have a 04 Titan Sidewinder with a compression release valve the one on rear cylinder is stuck in there a quick fix to unstick it without taking off cylinder head?
Thanks for the explanation! I've been trying to get my virtually new generator to run and I think the compression release is staying on. The unit is 2 years old and has less than 5 hours on it. I have only run avgas in it, no ethanol. I tried ethanol mogas because I thought the vapor pressure on the avgas might be too low, but that didn't help. It has spark, but I changed plugs anyway. Disassembled the carb, sparkling clean, but it feels like it's spitting air back out the air intake when cranking. After cranking 10-15 seconds, it drips fuel out the air intake. Manufacturer recommended complete new carb. Same result, so they sent another complete new carb. Same thing. Fuel shutoff on carbs work, oil pressure sensor has been plugged and unplugged. Crankcase vent has been disconnected from carb as it may have been the source for air spitting back through carb, but that didn't help, either. Checked valve clearance and one intake was tight. Set it to factory spec of .006" and no change. It will sputter a little if you pour gas or starting fluid directly into the intake manifold with the carb removed. I'm thinking either a sheared flywheel key or compression release not releasing. I hate to tear into the crankcase on an engine with only 5 hours. Do you know of a way to test the compression release without disassembly? This is a Champion 12000 KW generator, #100111. Thanks!
Can we rip this out and replace it with just a pull lever that operates it like on a diesal tractor? Everyone loathes these automatic compression releases that fail fail fail.
Hard to start even if the battery and starter are good. Rotate the engine by hand just past the compression stroke, and then start it. Might take a few tries to get it cranked, but it will crank. Also, use starting fluid, and then rotate the engine by hand just past the compression stroke.
Great video, thanks. Does this mean it is useless to do a compression test on any motor that has one of these? If so is there any way to know if a motor has one or not? Thanks again from a fellow Texan!
Cylinder leakdown test is the way to go. An easy way to tell if I engine has one is to look at the rocker arm or the valve if it’s an “L” head engine and watch for that .030” inch lift just before tdc
I have a 17.5 intek that's got no compression. It never smoked, it just stopped runnin. I took the plug out, put my finger on the hole and hand turned the engine. no compression what so ever. I put a rod in the plug hole and the piston is moving. the only noise it makes is a hiss inside the engine. Could the compression release be stuck open? The hiss is only on one of the strokes. I also set both valves at .004 and am sure the cam, rods, rockers, and valves function properly and the valve guides are set properly..
@@THEMOWERMEDIC1 slipped valve seat. I put it back in, set it in the head like diamond-setting with a punch, relapped the valves and reinstalled it. Runs fine.
@@ncrdisabled those double barrel Nikki carbs can be troublesome. You can do a balance test on the engine to figure out which barrel of the carburetor is not functioning properly
I read on an old lawn mower forum from 2008, that the Briggs and Stratton Van Guard, single cylinder engines, had the decompression release machined into the crankshaft and that it worked very well, and made the engines last a very long time. The guys talking on the subject said that Briggs and Stratton had gone to the present camshaft release "lobe" as a cost savings move, but that the In Tec engines, the ones with the faulty set up, were terrible and had a bad reputation for failure. Do you know if that is true? Excellent video, by the way.
Great video, dealing with 2nd broken compression release on 19HP 33R877 motor, any chance that the slightly earlier 31P777 cam (697762) will work in our motor ? It is all metal no plastic at the CR weight similar to the design you just showed. I would have to machine the groove for the oil pump drive bit have a milling machine. It seems on the late cams I am wondering if the weigh does not walk down the CR D shaped pin and get into contact with the tappet etc. that tiny open snap ring looks like its intended to keep that from happening but seems if it gets rotated the open end could allow the weight to get by it considering the CR weight is just hanging from the bottom side of the cam gear. If i need to replace that cam with the one with plastic I may tack weld a fork to make sure that weight cannot walk away from the lower face of the cam, any thoughts on making these failures not happen, This last fail bent the cam and broke the cam locating boss in the cylinder housing ? Thanks Ken
Huh, i have yet to pull apart any of my briggs 190cc motors and all 3 run a compression release. Now i know what it is and how it works. So there is no sacrifice at all, its soley to start the engine. Really cool. But i was looking to see if i can rig a compression relief for the 66cc chinese motorized bike engine on my bike. Around 600 to 800km it gets extremely hard to turn the engine over due to higher compression from the rings seating in tye cylinder. Once started it runs fine.
This was happening to me, it turned out to be a weak battery. It wasn't amping the starter enough to turn it over. I jumped it from the car battery, and it ran just fine. Just in case someone is checking off the easier fixes first before pulling the engine apart 👍
I have a 16 ph Briggs engine, and unless it spins really fast the engine back fires through the intake and exhaust and will only start on a battery with a full charge. Could this be a bad camshaft pressure release causing this issue?
What if theres a centrifugal compression . I have honda clone 196 on mini bike and after governor was taken out after plastic plug fell out. Its been hard to pull
I've replaced a broken one and one that was worn just enough to not provide enough of a release or bump to get it to start. I believe they had quality issues with who or how they were built. Both of these were near the 500hr mark.
So....I have an 07 gravely zt40 with a courage 17 and only 250 hours....I went out, mowed and all was great....went to go mow a week later and it's as if I have an open valve...spins super free, won't start. Ni checked the lifters and they are secure and moving while cranking. Anything to do with your topic?
@@THEMOWERMEDIC1 man...you won't believe this though. The old man that had it was beyond meticulous. He used those expensive precanned non ethanol gas products, drained the carbs and tanks of all his equipment and had books of service records. When I got this mower he had stashed it away because it quit running...even then...he emptied the carb out. I know this because in my trying to make the thing run I replaced the carb, pto switch, ignition switch, ignition module thing with the plug wire, battery, all fuel lines and finally got it running very nice. Anyway... suggestions on how to resolve? My thoughts would be to spray carb cleaner down the valves and try to get it loose and then change the oil. Am I being stupid? Lol
Have a GX270 Honda engine that was running perfectly, shut it down tried to restart and no compression. This engine is not that old and was starting first pull, could there be a problem with the decompression????
The compression release was working. I adjust valves.. compression got really tight. And when compression builds its kicks motor back and spin in reverse and destroys pull cord...adjust valves 30 times at top dead center of.compr3ssion stroke. Right when cylinder is at top after compression stroke. Still not engaging compression release. Compression release is the exhaust valve? Is it because it too loose or tomtight? I went from .010 - .001 snd no compression release
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
I'm taking an internal combustion engine class in college for an ME degree (senior year). Your explanation cleared up more in 5 minutes than an hours worth of textbook digging and google searching could. appreciate ya!
I'm 55 and I have wondered for years how the decompression mechanism works - you would not believe how happy I am to finally understand how it works! - Huge thanks for the video
Concise explanation without all the blah blah blah. Thank you!
Dozens of yt videos with small engine compression release explanations - this one is BY FAR the best. Thank you!
now I finally understand what this decompression valve is on my 84 Suzuki LT185. I've looked all over the net and this is the most detailed easily understood explanation of this topic. Thanks!
WOW!!! Finally someone, you, explain how these things work. I never knew .. Thank you
Thanks so much. 2:33 was the hit me over the head ah ha moment for me. I heard it explained many time but, your visual brought it to light for me. Thanks again.
Good video Jeremy. This should help people that don't understand how it works!
Been a machine for 35 years that is a verry good explication of how compression release works and i did know B/S had that in the small engines. thank you J C
@@skatkat6885 I know some people are "machines", never met one that admitted it though.
Great information here. I adjusted the valves on a tiller that was an absolute bear to start, and voila. I actually verified the spark plug was tight it pulled and started so easy!! Considering it would yank your shoulder off of your body prior, I was pretty excited.
I have a Kawasaki Fc420v, trying to start it, I would have my arm ripped out of its socket. I then realized that the valves needed adjustment. It was that mechanism that was giving me the problem! Thank You for the great video!
Well damn, I knew how the decompression worked on a big chainsaw but could not figure out how it worked on a larger mower engine... now I understand what people meant by "the bump". Thank you!
I've just started watching you in the last few months. Awesome. Thanks
Great explanation and demo. I have a vanguard 18hp that runs perfectly and strong, but if it doesn't start on the first pull, then the second stroke you feel on the second pull can break the cord. Then it starts every time at least on that third pull if it didn't on the first. Hoping it's this, and I can live with it. Nice to know how they work now though.
Awesome, informative, no BS video! I’m definitely going to start using “Like Yay…” in daily life!
Excellent Jeremy! I understood the concept, but, had never seen the exact detail in which the ACR worked before! Thanks again!
I am working for the first time on a Briggstratton CR 950 and was confused with the exhaust valve because it opens a little bit and it sucked a little air and then opens all the way and discharge. Thanks for this video I learned way.thanks
Allways wondered what that feeling of release was when I put my small engines at TDC for storage! Awesome vid!
Thanks for this video. A Gorilla couldn't pull the start cord on my new Honda engine. The service manager had me draining oil and pully the sparkplug before I came across your video. One hit with my rubber mallet apparently dislodged a stuck relief and the engine started with one pull. The engine was shipped to me and I suspect the relief moved. The engine has been starting easily since. Thank you very much!
Thanks!
I thought for sure there was something off about my cam. This explained it. Thanks a bunch!
I have the same Intek 18.5 HP engine that is in the video. Adjusted the valves at top dead center, and the engine was hard to start. Had to rotate engine by hand just past the compression stroke, and then it would start, and it ran good.
Adjusted the valves again at 1/4 inch past TDC, and bam it cranked right up every time. That 1/4 inch was the difference between hard to start, and cranking right up like it's supposed to do. I reckon the 1/4 inch past TDC has something to do with the compression release.
That same thing happened with my Briggs V-twin 22HP. Re-adjusted the valves by going 1/4 inch past TDC and worked. Started right up no problem. It won't crank past the compression stroke before doing this.
Thanks snippits75
I only had a basic understanding of compression releases on small four stroke engines. Thanks for explaining that.
You probably dont care at all but does anybody know a method to log back into an instagram account?
I stupidly forgot the login password. I would appreciate any help you can give me!
@Decker Apollo instablaster =)
@Magnus Clay I really appreciate your reply. I found the site thru google and I'm waiting for the hacking stuff atm.
I see it takes a while so I will reply here later with my results.
@Magnus Clay it worked and I finally got access to my account again. Im so happy:D
Thanks so much, you saved my account !
@Decker Apollo Glad I could help :)
Thank you. This is the only explanation I've seen of how compression release actually works.
Very clear and concise.
I knew the exhaust was opening early but did not know why, you told me and it was so simple once you explained, many thanks now subscribed. PS I'm was a body panel man, not a mechanic until retirement.
Great explanation! Have you done a video explaining how adjusting the valves works to solve this problem when the compression release is working normally?
Thanks, when I putting my Honda GXV140 crank shaft/timing gear back together I couldn't figure out the temporary hang up as I was turning the crank. Now I know.
Your videos are awesome as always !! Been watching you for years
really help video do some lawn mowers dont have compression realese? how can you tell?
Some do some don’t you would have to look up your engines specifications to be able to tell but you can just pull the valve cover and rotate the engine over and it should open the valve slightly right before top dead center
Good video now I understand a little bit more about how compression release works, I've been having the worst time with too much compression and in my riding mowers for the last couple of seasons. I keep readjusting the valves and they will run normal for a while but it doesn't last and I'm thinking it's got to be something else...
Thank you for your timer brother, My mower and i watched a lot of compression videos trying to fix it but this was the first showing what the hell makes it not work in the first place. Hopefully i can get it to run now that I know how it works
Great explanation MM1, and perfect timing have one in the shop now that I suspect has a bad compression release im going to show this video to my customer to help explain whats going on.
okay, thanks. I have a Coleman Powermate 6875 that takes about 35 pulls to start. Once it's starts it runs great. But I noticed it gets easy to pull just before it's going to start. So this sounds like the compression release to me. Thanks!
I love it. Short, straight to the point explained simply. Why some cams have no compression release? Is it for racing? Just got in to small engines not too long ago.
Thank you. Great explanation. Now I know how it works and finally can fix my little 15 hp Honda.
👍👍👍
Great. I have an old sears mower, probably 20 years old. 5.5 tecumseth i belive. It does appear to have that compression release. I had it appart to fix a broken camshaft. ( yes i tig brazed it back together. ) i thought it might be something else. But when you described how it stops, it makes sence. Ill look into to it. Thank you
Good job my man,got the message across clear and concise!
Thanks I wondered for years you cleared it up for me in a few minutes
thanks. my brand new honda hrx is having issues with the compression release, ugh!
It` a nice tutorial! Can you tell whether smaller Briggs engines have the same system, please? We have 7.25HP on our mower. According to its parts list, camshaft5 is made of green in color plastic (excluding its axle only :) Thank you
YOU ARE THE MAN, KEEP IT UP.
Thanks for the short & sweet show & tell. Really helps me understand.
Perfect! Thank you. Great explanation with visual aids!
Excellent! clearly explained how an automatic compression release works. I have a newbie question, why is there a need to release compression at that very moment and for a given angle? If someone posts an answer I will greatly appreciate it.
Its sole purpose is to make the engine easier to crank. So you can use a smaller battery, starter, etc. while at the same time running a higher compression engine which will have more power/efficiency.
Question sir, my 18 horse briggs,, my compression release is not broken, will worn lobes on cam cause me to have to adjust the valves every time I mow?
Awesome! This is the best explanation, and demonstration, of how compression release works that I've seen. Thanks TMM1!
Great video, and very clear explanation as to how that slinger lifts the valve....Thanks!
May I ask - in you experience, how far out of adjustment would the valves have to be, to make it hard to start? If they were out 0.001-0.002" would that make it hard to start?
On my 212 engine I put a starter could I take this out thank you the video was great
Very good explanation and video, thanks!
i have a 12hp briggs and just pulled out the cam . this engine ran ok full speed but like crap idle or hi idle . what i found is the intake valve was being held open thru the entire compression stroke just slightly but on top dead center it would close tight and clearance is .005 . is the cam lobe ground wrong ?
I got a question sir :) On a CG200 motorcycle engine will an aftermarket cam gear with decomp help relieve a kickback problem on my kick starter ? I gotta say my right leg sometimes hurt when my damn motorcycle kick starter kick's back 😵💫
I have a 04 Titan Sidewinder with a compression release valve the one on rear cylinder is stuck in there a quick fix to unstick it without taking off cylinder head?
How long has the compression release valve been around? I have an old John Deere Sabre engine that is probably 25 years old
Thanks for the explanation! I've been trying to get my virtually new generator to run and I think the compression release is staying on. The unit is 2 years old and has less than 5 hours on it. I have only run avgas in it, no ethanol. I tried ethanol mogas because I thought the vapor pressure on the avgas might be too low, but that didn't help. It has spark, but I changed plugs anyway. Disassembled the carb, sparkling clean, but it feels like it's spitting air back out the air intake when cranking. After cranking 10-15 seconds, it drips fuel out the air intake. Manufacturer recommended complete new carb. Same result, so they sent another complete new carb. Same thing. Fuel shutoff on carbs work, oil pressure sensor has been plugged and unplugged. Crankcase vent has been disconnected from carb as it may have been the source for air spitting back through carb, but that didn't help, either. Checked valve clearance and one intake was tight. Set it to factory spec of .006" and no change. It will sputter a little if you pour gas or starting fluid directly into the intake manifold with the carb removed. I'm thinking either a sheared flywheel key or compression release not releasing. I hate to tear into the crankcase on an engine with only 5 hours. Do you know of a way to test the compression release without disassembly? This is a Champion 12000 KW generator, #100111. Thanks!
My question is are the replacement cams from Briggs built stronger (thicker pin) than the old ones? I know the cheap knock-off ones aren't any good.
Is it on the intake valve ?
Jeremy very good demonstration. Big 👍 # 159
Stay safe, Joe Z
Awesome!! I'm gonna tell my customers to watch this so I don't have to explain it to them Lol Great video thank you
Can a broken cam release make a clattering noise? Thanks
Can we rip this out and replace it with just a pull lever that operates it like on a diesal tractor?
Everyone loathes these automatic compression releases that fail fail fail.
This is Sergey I like your videos how many compression releases have failed in your time of them have failed
Awesome video as usual Jeremy! There's your dinner!!!!
can you tell me if the 708cc toro Japanese engine has similar releases? can't find answers anywhere.
What are signs that the compression release spring is broken
Hard to start even if the battery and starter are good. Rotate the engine by hand just past the compression stroke, and then start it. Might take a few tries to get it cranked, but it will crank. Also, use starting fluid, and then rotate the engine by hand just past the compression stroke.
Clearer than mud. THX SIR!!! 🤟🤟🤟👍👍👍
I have a Subaru EX-40 engine. Had slight knock, I disassembled the engine and found the decompression release lever broken. Would it cause a knock?
Great video, thanks. Does this mean it is useless to do a compression test on any motor that has one of these? If so is there any way to know if a motor has one or not? Thanks again from a fellow Texan!
Cylinder leakdown test is the way to go. An easy way to tell if I engine has one is to look at the rocker arm or the valve if it’s an “L” head engine and watch for that .030” inch lift just before tdc
Thank you sir!
I have a 17.5 intek that's got no compression. It never smoked, it just stopped runnin. I took the plug out, put my finger on the hole and hand turned the engine. no compression what so ever. I put a rod in the plug hole and the piston is moving. the only noise it makes is a hiss inside the engine. Could the compression release be stuck open? The hiss is only on one of the strokes. I also set both valves at .004 and am sure the cam, rods, rockers, and valves function properly and the valve guides are set properly..
Stuck valve
@@THEMOWERMEDIC1 slipped valve seat. I put it back in, set it in the head like diamond-setting with a punch, relapped the valves and reinstalled it. Runs fine.
thanks for the info. i have a 18hp briggs 1991 duel spark plugs it acts like it has no power any ideas ?
V twin or
Opposed twin?
@@THEMOWERMEDIC1 v twin
@@ncrdisabled those double barrel Nikki carbs can be troublesome. You can do a balance test on the engine to figure out which barrel of the carburetor is not functioning properly
I read on an old lawn mower forum from 2008, that the Briggs and Stratton Van Guard, single cylinder engines, had the decompression release machined into the crankshaft and that it worked very well, and made the engines last a very long time. The guys talking on the subject said that Briggs and Stratton had gone to the present camshaft release "lobe" as a cost savings move, but that the In Tec engines, the ones with the faulty set up, were terrible and had a bad reputation for failure. Do you know if that is true? Excellent video, by the way.
Great explanation mate 👍
I think my 1977 Sears lawn mower with the 12 HP Tecumseh engine has compression release but I'm not sure. Does it have it??
Great video, dealing with 2nd broken compression release on 19HP 33R877 motor, any chance that the slightly earlier 31P777 cam (697762) will work in our motor ? It is all metal no plastic at the CR weight similar to the design you just showed. I would have to machine the groove for the oil pump drive bit have a milling machine. It seems on the late cams I am wondering if the weigh does not walk down the CR D shaped pin and get into contact with the tappet etc. that tiny open snap ring looks like its intended to keep that from happening but seems if it gets rotated the open end could allow the weight to get by it considering the CR weight is just hanging from the bottom side of the cam gear. If i need to replace that cam with the one with plastic I may tack weld a fork to make sure that weight cannot walk away from the lower face of the cam, any thoughts on making these failures not happen, This last fail bent the cam and broke the cam locating boss in the cylinder housing ? Thanks Ken
Huh, i have yet to pull apart any of my briggs 190cc motors and all 3 run a compression release. Now i know what it is and how it works. So there is no sacrifice at all, its soley to start the engine. Really cool. But i was looking to see if i can rig a compression relief for the 66cc chinese motorized bike engine on my bike. Around 600 to 800km it gets extremely hard to turn the engine over due to higher compression from the rings seating in tye cylinder. Once started it runs fine.
What is the decompression actually for? And is it needed ?
This was happening to me, it turned out to be a weak battery. It wasn't amping the starter enough to turn it over. I jumped it from the car battery, and it ran just fine. Just in case someone is checking off the easier fixes first before pulling the engine apart 👍
You are the man ! Good explanation sir. Thank You.
Do they ever fail to where it’s stuck decompressing? Got a 18 hp won’t start just bangs and blows air/fuel mixture out carb constantly
Great explanation 👍
I have a 16 ph Briggs engine, and unless it spins really fast the engine back fires through the intake and exhaust and will only start on a battery with a full charge. Could this be a bad camshaft pressure release causing this issue?
Good Video, I have a question. Do the smaller Briggs engines with no starter - pull start only, have the same setup?
Yep
Just subbed! If a two stroke chainsaw doesn’t have a compression release button then how does it work?
What if theres a centrifugal compression . I have honda clone 196 on mini bike and after governor was taken out after plastic plug fell out. Its been hard to pull
Really useful and concise explanation, thank you!
Can you actually grind the higher spot Down a little to make up clearance????
Thanks Jeremy
Can you buy just the decompression parts without buy camshaft?
Great video Jeremy
I have less than 400 hrs. on my b&s 1 cyl. and i have that symptom. Is this typical? Seems to me it should last longer.
I've replaced a broken one and one that was worn just enough to not provide enough of a release or bump to get it to start. I believe they had quality issues with who or how they were built. Both of these were near the 500hr mark.
Lololo that cam is much better than the new ones 😅
👍 I understand how it works now. , always wondered
How can I perform a leak down test on an engine that has a compression release mechanism? Any ideas?
Thanks for teaching. You are helpful.
So could a valve with to big of gap make this not work?
Exactly
So....I have an 07 gravely zt40 with a courage 17 and only 250 hours....I went out, mowed and all was great....went to go mow a week later and it's as if I have an open valve...spins super free, won't start. Ni checked the lifters and they are secure and moving while cranking. Anything to do with your topic?
Stuck valve from running engine on old gas. Seen it many many times
@@THEMOWERMEDIC1 man...you won't believe this though. The old man that had it was beyond meticulous. He used those expensive precanned non ethanol gas products, drained the carbs and tanks of all his equipment and had books of service records. When I got this mower he had stashed it away because it quit running...even then...he emptied the carb out. I know this because in my trying to make the thing run I replaced the carb, pto switch, ignition switch, ignition module thing with the plug wire, battery, all fuel lines and finally got it running very nice.
Anyway... suggestions on how to resolve? My thoughts would be to spray carb cleaner down the valves and try to get it loose and then change the oil. Am I being stupid? Lol
Have a GX270 Honda engine that was running perfectly, shut it down tried to restart and no compression. This engine is not that old and was starting first pull, could there be a problem with the decompression????
Yeassssss this is this video I need why dont Yu have millions of views
Great demo :) thanks!
The compression release was working. I adjust valves.. compression got really tight. And when compression builds its kicks motor back and spin in reverse and destroys pull cord...adjust valves 30 times at top dead center of.compr3ssion stroke. Right when cylinder is at top after compression stroke. Still not engaging compression release. Compression release is the exhaust valve? Is it because it too loose or tomtight? I went from .010 - .001 snd no compression release