I'm a weekly watcher of the channel and love Sunday mornings watching your latest posts. Today I was troubleshooting my lawnmower which was running rich. I did a google search and your old (7 years ago) video came up. Fortunately for me it was the exact same carborater. Your showing the part number quickly made my challenge easer. I ordered the replacement gasket/ diaphragm and I'm confident this will fix the problem. Your a quality act, keep it rolling. R, Phil
My briggs mower just started doing this with the first use this summer. I thought maybe it was the O-Ring that seals the intake to the carb so I replaced it with no luck. Thanks for this video brother. Gonna go pick up a new gasket tomorrow.
Perfect example of ethanol decomposing the rubber parts in the fuel system. It's guaranteed to fail again in another year or so. Repeat business from fuel related issues is amazing ! Great video brother
Just wanted to shout out a big thank you to you for this video! I had watched other videos as well and had taken my carb off multiple times and cleaned it put it back together. But was still experiencing the Rich running smokiness and rough idle. So when I saw you had to replace your gaskets oh, that was the ticket! I had ordered the gaskets and had them on hand but the last two times I took the carburetor part and cleaned it I did not replace them because they looked good. Anyway they still looked relatively good when I took them apart for the third time but this time I actually use the gaskets that I did order put them back together and Wallah it works like a champ!
I hate those stupid new plastic carburetors! I was given a mower by a family member who was seconds from tossing it in the dumpster because it did what this one did, but with the addition of shutting off totally after 5-10 seconds. I rebuilt the carburetor only to find it started doing it again a few mows later. Turns out the plastic was warped so the gasket wouldn't seal very well. For gits and shiggles I converted it to propane (I made a quick video of it here on TH-cam) and gave it to my neighbor.
There is a trick with plastic Brigs and Stratton pulsa jet carbs that involves placing a second gasket under the diaphragm on the fuel tank flange (same one that goes on top of it) this squeezes the diaphragm between the two when its torqued down so the edge of the diaphragm wont creep in and cause a leak
Thanks for the video. Let me just add that it is super important when you get the new gasket (mine was in 2 separate pieces, the diaphragm and the gasket) to place them in the correct position in between the carb and gas tank. Also, since the gasket is about $2 online, it would be wise to get a couple just in case one set gets damaged.
A very good point. I'd also like to add that it is always a good idea to purchase genuine Briggs and Stratton replacement gasket and diaphragms as reproduction ones tend to not last very long at all
Got a pressure washer with this style engine for free that's doing the same thing; though I think this may be what is wrong I'm going to go ahead and get a whole carburetor with the gaskets since I plan on keeping it indefinitely. Thanks for sharing!
Those b&s pulsa prime engines are great. Simple, reliable and long lived. It seems that at least 80% of any issues they have can be fixed by replacing that $3-4 diaphragm/gasket.
Just sold a mower similar to that, same issue as that one. Ebay or Amazon is my go to place for those diaphragm kits. As others are mentioning the ethanol in our fuel messes up all of our power equipment these days.
There is a trick with plastic Brigs and Stratton pulsa jet carbs that involves placing a second gasket under the diaphragm on the fuel tank flange (same one that goes on top of it) this layers the diaphragm between the two so when its torqued down so the edge of the diaphragm wont creep in and cause a leak , the diaphragm fuel pump, pumps fuel into the well in tank top, and when its full it runs out the overflow and right back into the tank (instead of closing the float needle) , ethanol biased fuels are hydroscopic and love to absorb moisture from the air (they don't cause these issues in automotive use because the fuel system is sealed not vented) drain the fuel in the tank into a clear container let it settle and check for water in the bottom. that water also loves to end up in the bottom of well in the top of the fuel tank that acts like a float bowl in a normal carburetor.
All plastic carb, thats why I avoid anything with a briggs and crap engine and only stick to Honda small engines. The GXV160 on my lawn mower and GX280 on my pressure washer both have all metal carbs except for the float and they have been super reliable. All I do each season is drain the fuel (tank and bowl) in the fall and in the spring I change the oil and they start usually on the first pull each time after sitting all winter. I have had them both over 10 years which they were used from CL when I got them and thats all I have had to do.
Rubber diaphragm goes on top of the fuel tank machined surface, followed by the gasket, followed by the plastic carburetor (with the diaphragm spring and main jet fuel screen in place)
I had that same thing happen with a power washer I bought brand new. I think the crap they put in the gas caused it. I think the additives in the gas softened up the diaphragm and caused the problem.
+Mustie1 is it possible to set the mixture on these? Mine is 100% the same carb. but sometimes it backfires slightly you can hear a "bub bub" sound from the carb. I will replace sparkplug and air filter maybe that helps
first check your linkage and make sure its not stuck in choke. theres a screw that can vibrate down and lock it in choke. if lever moves but the things dont move at the carb then its jammed up.
I have the same kind of tank and carb on a pressure washer but I am having a problem with the bulb not sucking gas up into it. I put a brand new carb and gasket set on it but it still does the same thing but i found if i tilt the washer up so the gas all flows towards the front then the bulb will reluctantly prime an the motor will start an run fine.
they sell those diaphragm kits everywhere Lowes Home Depot Walmart Meijer there about 5 bucks they come with the spring little metal thing the screen and the two diaphragms
plz don't wear shorts in vid again - it's frightening - but I like your vids all promote doing it once and doing it right and the hardest part of any project is getting started !
There's a briggs on my wood splitter and that carb suction drop tube has a screen on it that keeps plugging. I've cleaned the inside of the tank 10 times but it continues to plug with some kind of fiber stuff. The drop tube is almost touching the bottom of the tank. Any ideas?
jasonmushersee Some tanks have a sponge like material in them to help with sloshing around. When they get old they can deteriorate. Any chance yours has that? You can rip it out with some pliers if you do.
I have the same mower that is doing about the same thing, it is also blowing black smoke. cleaned the carb and tank and changed the diaphragm, no change.. if I tilt the mower back on 2 wheels it clears up and runs fine..????? any suggestions???
todd smith may be water inside the tank. you tilt it, water goes away from little pipe, that pulls gas, the engine starts to run better. If water, you would need to remove it. Another comment here suggested water could be inside the bowl, the one the guy wanted to clean. But if you engine works, there should be no water in that bowl, just the tank. Be very careful when working with fuel. No electrical drills, sparks.
What was the fix for your 3.5hp? I have the same problem on my 3.5 it's on an aerator so I cant replace the engine it has a gear box on it. Was it something with the carb?
Joe J. How does the air filter look? If those holes exposing the bottom of the filter get clogged they can act as a choke and cause it to run rich. I’d be interested to know!
Hey o have a lawn tractor that starts running hard and blowing black smoke around the half way throttle. The low throttle setting runs perfectly fine but it runs awful at medium to high
There are hidden internal mouse nests, that are causing the flux capacitor to produce more fuel output than needed. Thus causing you to drink more coffee and bounce off the walls. : )
I have a mower with the same engine and i changed the double layer diaphragm because mine would rev up and down like it was hunting, same thing, the edge of both layers didnt lie flat any longer. Also that side vent tube sometimes has a habit of spitting oil into the carb inlet and it causes hell, i leave the pipe off and capped off the carb side. Yes im evil as i vent the crankcase into the atmosphere a few times a year lol.
Only trouble is...From what I understand, the side vent that you took off is much like the PCV valve on your car or truck and it keeps a vacuum on the crank case to keep the rings sealed. With that tube not in in place it will wear the rings faster and shorten the life of the motor.
i had to replace the diaphragms on BOTH my pushers a couple years back. both freebies the newer poulan was given away BECAUSE of the issue. very cheap fix. yea those plastic shits are as is... SHIT. cant remove the jet but the pro is the carbs are only 25 bucks a pop. ibwish my 1962 wards tiller carb was that simple. i tried every replacable part and it still runs so rich its like a "ghost fog" not oil, soaks muffler fouls plug and wont pop off without a shot of carb cleaner when cold. warm it goes right away(flo-jet) but not bolted which is odd that early on.
I have this same problem, cleaned carb and tank and replaced gasket and diaphragm, filled with fresh gas still runs rich. if I tilt the mower back on two wheels it clears up and runs fine. any ideas??
ya know ya shouldn't run them carbs with that long air filter screw out of it, put the screw back in after u take the filter off, or they won't run right.
tommy hanlon That was true for the older choke systems from before the 80s. Trust me, i've had experience with both. These new plastic carbs don't have that. Good point tho
mustie before you even start, take the carb tank unit off, take the five screws out, clean the tank and put it in new diaphragm gasket kit. This is one of the easiest fixes ever, but something you have to do every so often as the edge of the gasket diaphragm gets sucked in causing a manifold vacuum leak. Also I've found that when you cant get the primer to work after it has sat a while put your hand over the carb a couple of times while running to help it get reprimed.
There's 2 special tools to replace the primer. It'll do the job better than by hand. It's expensive. $80.00 for the remover. Replace the fuel pickup also. To adjust the governor speed, bend the tang connected to the linkage. Get 2 screws the same as the air cleaner screws and cut off the tops and use them as installers to line-up for the diaphragm and other screws. Check leakdown and change the oil. There's a special tool to change the oil on a 4 h.p. Brigg. Amazon has it. The compression should be 90 lbs. The top ring is thin. Make sure to use a ridge remover! The oil control rings are 3 pc. Install inserts on the spark plug and head bolt holes. There is an oil seal on the intake valve.
Hello Im a subscriber I have a question I was hoping you could give some advice . I’m having a problem with a Briggs 14.5 rider mower it’s surging at hi speed and Sounds like it wants to backfire .the engine starts fine and idles fine the throttle and the choke are on the same control it’s a Murray mower 1994 if I run with the choke slightly on the surging etc smooths out a little adjusting the carb screws does not seem to affect changes . I’ve only found 1 example on you tube what this sounds like this is the link th-cam.com/video/i2lU8AGWwFQ/w-d-xo.html
That was a disappointment, you are usually a good teacher and I like watching your videos, but a lot of people watch these videos because they can't remember how the diaphragm and gasket went on, and I think that you left out the most important part of the process.
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I'm a weekly watcher of the channel and love Sunday mornings watching your latest posts. Today I was troubleshooting my lawnmower which was running rich. I did a google search and your old (7 years ago) video came up. Fortunately for me it was the exact same carborater. Your showing the part number quickly made my challenge easer. I ordered the replacement gasket/ diaphragm and I'm confident this will fix the problem. Your a quality act, keep it rolling. R, Phil
My briggs mower just started doing this with the first use this summer. I thought maybe it was the O-Ring that seals the intake to the carb so I replaced it with no luck. Thanks for this video brother. Gonna go pick up a new gasket tomorrow.
As always, to the point, informative and nice to watch.
Thanks,
Chris
Gatineau, Quebec, Canada
Perfect example of ethanol decomposing the rubber parts in the fuel system.
It's guaranteed to fail again in another year or so. Repeat business from fuel related issues is amazing !
Great video brother
I think Cliff Clavin from Cheers is fixing mowers now. Good video!
That was cool taking us thru the troubleshooting. Thanks. Mike
Just wanted to shout out a big thank you to you for this video! I had watched other videos as well and had taken my carb off multiple times and cleaned it put it back together. But was still experiencing the Rich running smokiness and rough idle. So when I saw you had to replace your gaskets oh, that was the ticket! I had ordered the gaskets and had them on hand but the last two times I took the carburetor part and cleaned it I did not replace them because they looked good. Anyway they still looked relatively good when I took them apart for the third time but this time I actually use the gaskets that I did order put them back together and Wallah it works like a champ!
Guess I can't take a picture and attach it but the Briggs & Stratton item number I used with 795083 carburetor diaphragm kit
Thanks that was the problem with mine, had been running rich and smoking black for years...now its running great!
Thank you, your fix was right on the money, runs like new now.
I hate those stupid new plastic carburetors! I was given a mower by a family member who was seconds from tossing it in the dumpster because it did what this one did, but with the addition of shutting off totally after 5-10 seconds. I rebuilt the carburetor only to find it started doing it again a few mows later. Turns out the plastic was warped so the gasket wouldn't seal very well.
For gits and shiggles I converted it to propane (I made a quick video of it here on TH-cam) and gave it to my neighbor.
There is a trick with plastic Brigs and Stratton pulsa jet carbs that involves placing a second gasket under the diaphragm on the fuel tank flange (same one that goes on top of it) this squeezes the diaphragm between the two when its torqued down so the edge of the diaphragm wont creep in and cause a leak
You are one heck of a mechanic sir.
The shit in the gas now runs the diafram I have changed so many of them . I keep at least 5 on hand all the time . Great video Darin
5 of them ? How long these gaskets last ?
Awesome Video , I Really Love Your Videos On VW First Start In Decades Too
Nice job I always learn from your vids thanks for sharing.
Pulse prime carb, easy and cheap to fix or replace.
Can’t believe I missed this video after all these years.
Thanks for the video. Let me just add that it is super important when you get the new gasket (mine was in 2 separate pieces, the diaphragm and the gasket) to place them in the correct position in between the carb and gas tank. Also, since the gasket is about $2 online, it would be wise to get a couple just in case one set gets damaged.
A very good point. I'd also like to add that it is always a good idea to purchase genuine Briggs and Stratton replacement gasket and diaphragms as reproduction ones tend to not last very long at all
Got a pressure washer with this style engine for free that's doing the same thing; though I think this may be what is wrong I'm going to go ahead and get a whole carburetor with the gaskets since I plan on keeping it indefinitely. Thanks for sharing!
yes sir, that's how it's done brother, great fix. cheers
Those b&s pulsa prime engines are great. Simple, reliable and long lived. It seems that at least 80% of any issues they have can be fixed by replacing that $3-4 diaphragm/gasket.
100%
I even ran ours on gas / cooking oil mix for a bit, smelled like fries. These things are impossible to stop, true workhorses.
Good Work !!! Thanks for posting.
More ethanol related mayhem. Nice fix
Just sold a mower similar to that, same issue as that one. Ebay or Amazon is my go to place for those diaphragm kits. As others are mentioning the ethanol in our fuel messes up all of our power equipment these days.
For walking in to a store , i am impressed it was only $3.40 . It is around $12 for me at our local store .
I love it when a plan comes together...
That was an excellent how to, Sir.
Very nice. I would not have thought of that. Thanks :)
thanks for the vid. I have the same brand mower and it does the same thing. at least I have a starting point when I go to fix it.
Thanks for the great instructional.
NICE RED SHORTS WITH THE COOL RACING STRIPES!!!!!
Thanks for sharing !! I have a B&S pressure washer with identical engine and I'm pretty sure this'll fix it.
Oh yeah running better now, nice job spotting that carb gasket. See ya
Wow! Would never get those parts here for that much 😱😱😱 so cheap. Nice!
Amazon. $3 all day.
Nice quick repair... gotta love it. Ooooo D-man in shorts, the ladies gotta love them legs! (grin)
You da man mustie, keep em runnin.
There is a trick with plastic Brigs and Stratton pulsa jet carbs that involves placing a second gasket under the diaphragm on the fuel tank flange (same one that goes on top of it) this layers the diaphragm between the two so when its torqued down so the edge of the diaphragm wont creep in and cause a leak , the diaphragm fuel pump, pumps fuel into the well in tank top, and when its full it runs out the overflow and right back into the tank (instead of closing the float needle) , ethanol biased fuels are hydroscopic and love to absorb moisture from the air (they don't cause these issues in automotive use because the fuel system is sealed not vented) drain the fuel in the tank into a clear container let it settle and check for water in the bottom. that water also loves to end up in the bottom of well in the top of the fuel tank that acts like a float bowl in a normal carburetor.
Tank IS the float bowl! :-)
Think I'd have popped the plug out to check it. I know you hand over the intake was a pretty good empirical check, but the plugs never lie.
One of the easiest repair in mower engines - changing these diaphragms ;)
The order of the gasket and diaphragm is important - I can't remember which way but I do know that it has to be the correct order
All plastic carb, thats why I avoid anything with a briggs and crap engine and only stick to Honda small engines. The GXV160 on my lawn mower and GX280 on my pressure washer both have all metal carbs except for the float and they have been super reliable. All I do each season is drain the fuel (tank and bowl) in the fall and in the spring I change the oil and they start usually on the first pull each time after sitting all winter. I have had them both over 10 years which they were used from CL when I got them and thats all I have had to do.
The all plastic carb wasn't the problem, the rubber diaphragm was. B&S have always been reliable for me.
Whereas I've had Hondas that have been nothing but trouble, so I guess you mileage varies..
Mine runs rich and uneven just like that too....!!!....I need a new Gasket and Diaphragm.....Thanks Mustie1.
Rubber diaphragm goes on top of the fuel tank machined surface, followed by the gasket, followed by the plastic carburetor (with the diaphragm spring and main jet fuel screen in place)
Have had that plastic carb /gasket problem several times ! Since they went to plastic I see it quite a bit !!
I definitely learned something here.
This fixed mines! Preciate it!
nice fix
Good Job Mustie1...
Got one of thease with bad piston rings but for free is gonna be great for beating the shit out of it
I had that same thing happen with a power washer I bought brand new. I think the crap they put in the gas caused it. I think the additives in the gas softened up the diaphragm and caused the problem.
Freak'n ethanol...found a place that sells ethanol free...it's out there, just gotta look...good job, sir
I had similar issue and replaced the diaphragm and gasket. Worked great for the first mow but then it started acting the same way again. Any ideas?
+Mustie1 is it possible to set the mixture on these? Mine is 100% the same carb. but sometimes it backfires slightly you can hear a "bub bub" sound from the carb. I will replace sparkplug and air filter maybe that helps
Gods diagnoses and repair, thanks again. Blocking the carb with hand is simple yet effective way of determining lean/rich issues.
first check your linkage and make sure its not stuck in choke. theres a screw that can vibrate down and lock it in choke. if lever moves but the things dont move at the carb then its jammed up.
Nice save
I have the same kind of tank and carb on a pressure washer but I am having a problem with the bulb not sucking gas up into it. I put a brand new carb and gasket set on it but it still does the same thing but i found if i tilt the washer up so the gas all flows towards the front then the bulb will reluctantly prime an the motor will start an run fine.
they sell those diaphragm kits everywhere Lowes Home Depot Walmart Meijer there about 5 bucks they come with the spring little metal thing the screen and the two diaphragms
plz don't wear shorts in vid again - it's frightening - but I like your vids all promote doing it once and doing it right and the hardest part of any project is getting started !
There's a briggs on my wood splitter and that carb suction drop tube has a screen on it that keeps plugging. I've cleaned the inside of the tank 10 times but it continues to plug with some kind of fiber stuff. The drop tube is almost touching the bottom of the tank. Any ideas?
jasonmushersee Some tanks have a sponge like material in them to help with sloshing around. When they get old they can deteriorate. Any chance yours has that? You can rip it out with some pliers if you do.
dude RED shorts really, great vid as always though , just check with Mrs Musty about your choice of clothing first eh mate :)
I have the same mower that is doing about the same thing, it is also blowing black smoke. cleaned the carb and tank and changed the diaphragm, no change.. if I tilt the mower back on 2 wheels it clears up and runs fine..????? any suggestions???
todd smith may be water inside the tank. you tilt it, water goes away from little pipe, that pulls gas, the engine starts to run better. If water, you would need to remove it. Another comment here suggested water could be inside the bowl, the one the guy wanted to clean. But if you engine works, there should be no water in that bowl, just the tank. Be very careful when working with fuel. No electrical drills, sparks.
Good video
How I can repair the carborator
Mustie classic rewind!
Same problem on my 2002 briggs 3,5 hp. I put in a new sparkplug and it had only run like 2 hours and it was caked with carbon
What was the fix for your 3.5hp? I have the same problem on my 3.5 it's on an aerator so I cant replace the engine it has a gear box on it. Was it something with the carb?
Joe J. How does the air filter look? If those holes exposing the bottom of the filter get clogged they can act as a choke and cause it to run rich. I’d be interested to know!
nice
Hey o have a lawn tractor that starts running hard and blowing black smoke around the half way throttle. The low throttle setting runs perfectly fine but it runs awful at medium to high
I have the same problem with my mower, i'm interested in how you fix that problem.
i would never wire that on off clamp thing never you know i wouldnt much
There are hidden internal mouse nests, that are causing the flux capacitor to produce more fuel output than needed. Thus causing you to drink more coffee and bounce off the walls. : )
I have a mower with the same engine and i changed the double layer diaphragm because mine would rev up and down like it was hunting, same thing, the edge of both layers didnt lie flat any longer.
Also that side vent tube sometimes has a habit of spitting oil into the carb inlet and it causes hell, i leave the pipe off and capped off the carb side.
Yes im evil as i vent the crankcase into the atmosphere a few times a year lol.
Only trouble is...From what I understand, the side vent that you took off is much like the PCV valve on your car or truck and it keeps a vacuum on the crank case to keep the rings sealed. With that tube not in in place it will wear the rings faster and shorten the life of the motor.
i had to replace the diaphragms on BOTH my pushers a couple years back. both freebies the newer poulan was given away BECAUSE of the issue. very cheap fix. yea those plastic shits are as is... SHIT. cant remove the jet but the pro is the carbs are only 25 bucks a pop. ibwish my 1962 wards tiller carb was that simple. i tried every replacable part and it still runs so rich its like a "ghost fog" not oil, soaks muffler fouls plug and wont pop off without a shot of carb cleaner when cold. warm it goes right away(flo-jet) but not bolted which is odd that early on.
ur magical tanx
No tax in N.H.?
You almos wonder why you cant go to a supply house and order a good old Farnicastaff that can replace a lost one.....because they never go bad.
Fixes?
I have this same problem, cleaned carb and tank and replaced gasket and diaphragm, filled with fresh gas still runs rich. if I tilt the mower back on two wheels it clears up and runs fine. any ideas??
ya know ya shouldn't run them carbs with that long air filter screw out of it, put the screw back in after u take the filter off, or they won't run right.
tommy hanlon That was true for the older choke systems from before the 80s. Trust me, i've had experience with both. These new plastic carbs don't have that. Good point tho
It's a little hard to see because the camera youre using is very blurry
mustie before you even start, take the carb tank unit off, take the five screws out, clean the tank and put it in new diaphragm gasket kit. This is one of the easiest fixes ever, but something you have to do every so often as the edge of the gasket diaphragm gets sucked in causing a manifold vacuum leak.
Also I've found that when you cant get the primer to work after it has sat a while put your hand over the carb a couple of times while running to help it get reprimed.
Thanks for the video!
There's 2 special tools to replace the primer. It'll do the job better than by hand. It's expensive. $80.00 for the remover. Replace the fuel pickup also. To adjust the governor speed, bend the tang connected to the linkage. Get 2 screws the same as the air cleaner screws and cut off the tops and use them as installers to line-up for the diaphragm and other screws. Check leakdown and change the oil. There's a special tool to change the oil on a 4 h.p. Brigg. Amazon has it. The compression should be 90 lbs. The top ring is thin. Make sure to use a ridge remover! The oil control rings are 3 pc. Install inserts on the spark plug and head bolt holes. There is an oil seal on the intake valve.
Replaced the diaphram but no improvement?
You watch video no?
Hello Im a subscriber I have a question I was hoping you could give some advice . I’m having a problem with a Briggs 14.5 rider mower it’s surging at hi speed and Sounds like it wants to backfire .the engine starts fine and idles fine the throttle and the choke are on the same control it’s a Murray mower 1994 if I run with the choke slightly on the surging etc smooths out a little adjusting the carb screws does not seem to affect changes . I’ve only found 1 example on you tube what this sounds like this is the link th-cam.com/video/i2lU8AGWwFQ/w-d-xo.html
the carb is dirty, it will need to be taken apart and cleaned
migos
Nice video. I’d like to give a shout. Out to BRUCE PENDER HERE ON YOU TUBE. CHECK HIM OUT SOMETIME
Called a pulsa,jet carb
the problem was water filling the bowl you could see it in the video. You dumped it without spotting it.
That's gasoline, John.
That was a disappointment, you are usually a good teacher and I like watching your videos, but a lot of people watch these videos because they can't remember how the diaphragm and gasket went on, and I think that you left out the most important part of the process.