Briggs & Stratton 5-6hp Engine | Carburetor Primer Bulb Plate Fix When 2 Gaskets Don't Work(Updated)

[@leftyjaysmith]

I followed your directions and used black rtv. Let it set overnite. Installed the next day and it worked like a charm. THANK YOU!

[@TheNovaJohn]

Glad it Helped!!!

[@nick_vee]

Perfect timing. I found your first video about this and it led me to this updated one. Grass cutting season is now here and just for shits and giggles I thought there has to be a fix that didn’t involve carrying around a can of starting fluid and a screwdriver to remove the air cleaner to get this damn thing started every time. Like you said, two gaskets didn’t work and looking closer at that plastic backing plate, I saw one section of the raised edge of the air channel was smashed down (screws tightened too much). I layed down a coating of gray RTV and put down the gasket to seal up the air channel. Let it set overnight, set down a second gasket (they’re cheap enough) and just snugged the three screws holding the plastic backing plate. Pressed the primer bulb and… we had gas squirting up into the carb! One pull and back in business! The engineer who designed this priming system should be shot. Must be the same guy who came up with the ventless gas containers with the high spill nozzles. Keep on posting these great videos, Arch!

[@TheNovaJohn]

Not sure how I didn't see your comment! Glad this helped.. Thanks for watching!!!

[@richards6346]

Thanks for posting the silicone RTV fix. Just did one that I had wrote off, after the double gasket didn't work. Not going to get into how many I have struggled with over the years. But I will now have a spare one available beside the rebuilt tin tank off the older ones.

[@TheNovaJohn]

Thanks Richard, There are times it wont work, mostly when the plate is cracked or badly warped. There is a way to heat the plate with a heat gun and get it back into shape. I collect these, clean them and lay out a few at a time. I just used my last 2 pieces and they worked fine,,,,time to make more!

[@richards6346]

@@TheNovaJohn I did find a video on how to straighten the warp with a heat gun, may give that a try as well.

[@TheNovaJohn]

I think Bruces Shops has one

[@davidb2438]

After I fixed an issue with the carburetor I had the primer problem. I did your fix and it worked perfectly, thx, I m ashamed I didn’t think of it myself.

[@TheNovaJohn]

I'm glad it helped!! Took me a while to get this right!!

[@waynestefinashen239]

Nice video Arch i only put the gasket maker in the high ridge side of the air box where it has not formed on the gasket but your idea of covering in the gasket also works great. We also remove the primer bulb and clean out the inside screen but usually install a new primer bulb at a very small profit margin since customers appreciate the clean look of a new primer bulb. We have the B&S removal tool figuring it pays for itself in a short period of time and eliminates the possibility of impaling some body part with a screwdriver. The installation tool can easily be made with a piece of pvc piping with notches cut out and a T fitting applied to act as a handle. Thanks for the shout out the OLD MAN at EP over and out.

[@TheNovaJohn]

Great suggestion! Thanks for watching. Eventually I will make that PVC tool and buy the B&S

[@jamesshivers8213]

I'd like a how to video on the homemade install tool. How bout it?

[@waynestefinashen239]

James if you check out Jakes video B&S removal and installation tools you can see the tools we have purchased. The 19461 removal tool eliminates the use of screwdrivers for bulb removal and eliminated impaling your hand with a screwdriver. This tool could easily be made by welding some bent key stock to a set of old pliers although you would need to pry the handles open to apply the pressure on the plastic tabs to remove the primer bulb. The install tool 19462 can simply be made with a piece of pvc tubing that fits into the inside diameter but needs two notches cut out on the end to fit over the plastic tabs, a T connection can be glued to the main part to provide a handle to provide more comfort to the palm for pushing it in. Jake is at Eliminator Performance KZbin if you have not seen the channel. Not sure if Jake will be able to do a video on making this tool but i will forward dimensions to you in case he does not have the time shortly.

[@jamesshivers8213]

Thanks

[@waynestefinashen239]

@@jamesshivers8213 The B&S installation tool is #19462 the OD of the pvc tube is 0.975" with an ID of 0.802" or 0.086" wall thickness and the overall length of this piece is 3" long and has a mushroom style head attached. The two slots on the pvc tube end are directly across from each other and measure 0.462" wide with a depth of 0.198". If you go to a hardware store try to find a fitting or piece of pvc tubing that comes close to these dimensions and cut the slots using a hacksaw then a grinder with cutoff disc to grind down to the depth shown. Using a scribe to scratch the surface helps control dimensional locations and you can always finish to the line with a file.

[@darellsunderlin4670]

Just finished one today . I did it alot like you but I was doing a little testing first. I only put gasket maker sealer on the carb side and tried it , didn't work so I put it in the primer plate side , let it sit for awhile and it primed and started . I've worked small engines for over30+ years and like you have done many . I use the gray permatex , find it works on about anything. Great video!

[@TheNovaJohn]

I want to try the gray, I use the black but I recently tried the Hi Temp version and it failed immediately. The gas was eating it up. Thanks for watchin!!

[@Rein_Ciarfella]

Unbelievable timing! Just picked up two Craftsman B&S flathead mowers the same day I came across this video! Everything else I’ve seen so far are OHV so I wasn’t familiar with this type of engine. One is 6.25 and the other is 6.75. One with a chewed off spark plug boot and the other with a broken pull cord. Both sitting for at least a year and with other minor issues so it’s very likely I’ll need to perform this same operation on both. Found you while researching DIY lift tables. Subbed! Thanks!

[@TheNovaJohn]

Great Story,,,,thanks!!

[@gradyhernandez4699]

I have a Toro personal pace mower that won't prime,so I'm going to follow the video

[@gradyhernandez4699]

Use an 18mm socket or 3-4 inch to push bulb in

[@metoon3092]

Oooooh the Briggs gasket ! The last 2 that I have done, I have cut the gasket right apart above- the 2 screw hole(s). This I believe leaves a gap to ultimately force the gasket to seal only in it's remaining area. I tried the wet gasket, it did not work for me either. Thanks Arch !

[@TheNovaJohn]

Nice Idea!

[@philliphall5198]

At this time I’m using 1/4 body washer cut to fit and it’s working so far, I used heat gun and got it real hot and tighten it up by hand

[@patandsandytrierweiler2440]

Great video. The B&S bulb plate is prone to air puff leaks/warping. Bad design. Only a matter of time until failure. Once the two gasket fix fails, my plan is to trace/cut out an aluminum foil bulb plate gasket. Using automotive gasket sealer and a toothpick, I seal my aluminum gasket to the air channel of the bulb plate. Two bulb plate gaskets (no sealers here) plus two washers, and tighten only as necessary. I liked your RTV technique too.

[@TheNovaJohn]

Give it a shot,,,I have another video where I tried something like this and it didn't go as well as this! Thanks fer watching and I hope this helps

[@sonofthe80s]

I used a small square of sheet metal tape, after I cleaned the base area well w/ alcohol I stuck the square over the pins then placed a gasket over the tape and trimmed excess tape off. Works great! Sheet metal tape is strong and sticky, if your base is clean this should work. Sheet metal tape is expensive but I had it on hand.

[@TheNovaJohn]

Nice,,, good to be resourceful !

[@deltafour1212]

@sonofthe80's Sheet metal tape still working?

[@sonofthe80s]

@@deltafour1212 No, it lasted until just recently. I then installed a brand new cover and learned a $20 lesson about overtightening. Good news is, it primes like crazy now.

[@deltafour1212]

@@sonofthe80s You're lucky. I bought an OEM (it says it was) B&S $20 plate and still won't prime.

[@ldaly4621]

Thank you. Great tip

[@UnhingedHarry]

Thanks, some good tips there. I have one of those engines and about to clean the carby. It would start and run with petrol sprayed into the inlet. So 99% sure it's the carby. Fuel supply from the tank was OK.. And there's you dinner.. whoooo weeee... Nice safety crocs too, I have a few pairs.

[@TheNovaJohn]

Thannx Harry,,, Yea I need a new pair of crocs too but thankfully its not too hot,,,YET!

[@waynestefinashen239]

Arch i put the OEM B&S gasket in boiling water for 5 minutes then install it on the plate and mount the plate hand tight as you did. I then remove the three 5/16" hex screws and remove the gasket to see how much of the hockey stick impression has been formed on the gasket if an area is only partially formed i normally reinstall it then use a 1/4" flat punch and lightly tap the back of the gasket to fully form the hockey stick impression then reinstall and this guarantees me full prime. This only works if the primer plate is not badly warped if it is i use a bamboo skewer and only apply RTV silicone to the outer ridge side of the primer plate this always solves the issue. Your method is full proof! Aftermarket gaskets are much thinner and harder than the OEM gaskets and i have never used two. If the mower as received is priming properly (approximately 3/8" high shot of fuel out of the tube) i will always use the original gasket since it already has the ridge deeply impressed into it from the primer plate (if there is a slight tear in it a little dab will do you of RTV). Thanks for the shout out the OLD MAN at EP.

[@TheNovaJohn]

I suspected as much,,,,now i need to pin this reply so everyone can see it!! Thanks!!

[@Rein_Ciarfella]

@@TheNovaJohn Hey, Arch! Me again! 😉 I completely forgot about this video but I guess it marks our one year anniversary! Do you still love me? 😂 You forgot to pin Wayne’s comment so this is your official reminder, dude! Us old guys gotta stick together! One question, now that I’ve got over a year’s worth of KZbin videos and experience under my belt. I’ve been using Threebond 1184 for all sorts of things and I’m thinking if applied correctly but in a slightly different way it might be another way to solve this problem. Kind of combination of both yours and Wayne’s methods. Apply a very thin layer of 1184 to both the gasket AND the clean plate in the area that does not seal, allow to dry, apply a thin coat of oil (so you can remove the plate for future cleaning without having to replace the gasket) and mount the plate. I’ve been using this method instead of base gaskets on chainsaws very successfully. Having two thin layers which are dry enough to not squeeze out or bond to another surface eliminates the problem of squeeze out and cylinder contamination yet provides enough forming ability to compensate for any warping, gouging or whatever between the two surfaces. Want to try one this way to see how it compares? You too, Wayne?

[@TheNovaJohn]

@@Rein_Ciarfella LOL,,,,,Glad to have ya Rein!!! Its pinned,,,,been pinned,,,

[@jamesshivers8213]

Im gonna try your trick to it. My sin has a project mower with the primer problem. We ordered a new plate, but , we are gonna try this b4 we try the new plate. Thanks for the video

[@TheNovaJohn]

Great,,, works for me....Thanks for Watchin!!

[@richm720]

Great Job Arch Saved me from pulling my hair out

[@TheNovaJohn]

Great!! Thanks fer Watchin

[@crisprtalk6963]

I'll give it a try tomorrow. thanks.

[@TheNovaJohn]

Great,, good luck Crispr

[@MrEricdgreat]

Can gray RTV be used???? Instead of the black . Thank you

[@TheNovaJohn]

Probably, I do know that some of the Gray Silicon is like a general purpose. Not sure who makes it. I can't say for sure because I haven't tried it yet!

[@sheri023]

It looks like the RTV glue is blocking the hole where the bulb air comes out, but I guess that is not the case if it primes. Does the air from the prime cause a suction for fuel to come out of the fuel line and into the carb? I'm new at this and doing my first one on a Briggs (craftsman) walk behind trimmer. Thanks for the video.

[@TheNovaJohn]

I mention this in the video; pushing the primer bulb causes an "overpressure" in the float bowl thus pushing raw fuel up and spills over into the throat of the carb. At 23: I test a viewers suggestion and start talking about this again. His suggestion didn't work so I put my version of the fix in while I was outside on the lawn. Not much fuel is needed to "prime" the engine. Just a simple few puffs does the trick. unfortunately these plastic pieces warp, the gaskets go bad and dirt builds up, all conspire to fail the system.. Keep learning, it can save you money and It's fun too! Thanks for watching!

[@sheri023]

@@TheNovaJohn thank you for the explanation.

[@deltafour1212]

Can a Briggs and Stratton quantum engine be converted from a primer bulb to an auto choke carb?

[@TheNovaJohn]

Yes, but to do it correct you will need a donor engine and both engines need to be off the machines. There is a plate/air baffle that holds the spring for the choke and its bolt is under the engine. I do have a few videos where I show this. Some of my builds are conversions

[@josephaguiar1817]

I have the same mower as the one you showed in your video. When does the choke close on these carbs? Does the engine need to be running for the governor lever to start pulling back? Great video. I'll definitely try it to see if the primer plate is the problem.

[@TheNovaJohn]

There is NO choke,, its a push primer! You may be referring to the Throttle blade? Yes the engine when its running has a part that is connected inside called the governor, as you mentioned. As the engine sees an increasing load the RPM drops, to compensate there is a spring on the throttle of the carb, it pulls the throttle open more. If the engine speed goes beyond the limit of the governor, thus device pulls back against the spring until the preset adjustment and rpm is reached again. In these motors, the governor is connected to the crankshaft, it has a gear and 2 fly weights that get thrown outward due to centrifugal force, they are connected to the outside of the engine through that Rod you mentioned. I hope this helps Thanks for watching

[@philliphall5198]

Have you tryed cleaning in ultra sonic cleaner for 10 minutes??

[@TheNovaJohn]

Only Rich people have those!! I cant afford one.

[@mowman1423]

Thanks for the tip I have 2 mowers that I even spent money buying new backing plate & still wouldn't prime going to try this trick was about to give up lol

[@TheNovaJohn]

Dont Give Up!!! Thanks for watching,,,any questions? Let me know

[@kevinwest1695]

Hey Arch, kuddos. It worked ! But I managed to lose the screws that hold plate on(I pulled some off another mower that I now need to replace) do u know what size or part # I need ? Again many thanks, was goin crazy…

[@TheNovaJohn]

Take one over to the hardware store,, I think they may be 10/32 or 8/32 you'll find something

[@stephenspencer1758]

Hi Arch thanks for the informative video, my problem is the fuel leaks out of the air hole on the priming bulb, do you think if I installed the gasket your way this problem would be rectified?

[@TheNovaJohn]

Probably not, there shouldn't be any fuel coming from the primer bulb, you have a float problem or some other issue. Sounds like its time to rebuild the carburetor

[@cherokeefiddler]

Gonna try it!

[@TheNovaJohn]

Just let it dry!!

[@vinopan5374]

Hi Arch, tried your RTV gasket repair for the base primer plate on 6HP B&S engine. New primer bulb and your suggested Panari carb gaskets were used. Everything super cleaned. It worked great. However, after starting and running several times ( hot and cold engine) it failed. I used the ultra black RTV . Repeated twice and same results. Any suggestions! Do you think ultra black RTV vs standard RTV could be an issue? Thanks Arch, enjoy your videos!

[@TheNovaJohn]

Is the plate cracked? Get a new one. I have seen some that were so warped that nothing fixed it. I take them all apart, clean out the push primer bulb. Those ports get clogged. Also make sure you didn't clog the ports with RTV...

[@vinopan5374]

@@TheNovaJohn No , the plate is not cracked. I did purchase a new OEM PLATE and I am waiting for it to arrive. I think you’re correct , the bottom ridge trace where the gasket lies in place , seems worn or flattened out, it’s a low spot compared to the remaining ridge both top and bottom. Different RTV no problem? Thanks, Vin

[@TheNovaJohn]

@@vinopan5374 Kewl,,, as long as its rtv it shouldn't matter

[@vinopan5374]

@@TheNovaJohn New plate solved the problem. If your interested I should send you the old plate to take a look and see if you can get it to work. I got it to work twice but didn’t last very long.

[@TheNovaJohn]

Thanx Vin,,,,been there done that lol,,,,,Keep it, nail it to the wall.. I keep a few already done on hand and if one of those don't work its chucked and I grab another....

[@emilyreid652]

Very helpful, thanks bro 👍

[@TheNovaJohn]

Thanks!!! & Thanks for watching!!

[@gradyhernandez4699]

Thanks

[@TheNovaJohn]

Hope it helps Grady!!!!

[@gradyhernandez4699]

@@TheNovaJohn I will try it when I get out of doc office

[@mowman1423]

update this is the only sure fix after sealing the faulty designed backing plate gasket started 1st pull thanks!

[@TheNovaJohn]

Great & thanks for the update!!

[@sonnyc3826]

what happens when you have to change the gasket? its glued on. i used a piece of tape i got from another video it worked ok..i mean at least it starts now..its a bit rough stutters a bit i guess but at least it starts now...alot fo things can work but this is just an annoying problem./.i went looking eveyrhwere for solutions and no-one would answer and then years later i come across these videos about this problem so itried the tape trick and it worked.. pretty shitty design tbh..the steel ones were better at least they dont warp

[@TheNovaJohn]

Yea,, cheap isnt it! Its not glue, its RTV and it comes right off but that would be years from now and for my customers, probably never! They throw these machines out after absolutely trashing them! Nice thing about this is its removable, doesn't interfere with anything and will seal much better then tape! Thanks for watching!

[@plinioiweb7269]

perfect ! on. my mower

[@philliphall5198]

Heating it seems to work 99% of the time, just keep it bent while cooling down and one gasket Or right stuff silicone also if all fails

[@TheNovaJohn]

Yea I've tried that too, this is quicker, easier and I can drop a bunch of these on the bench and shove them on a shelf for future projects! I never got a notification for your comment BTW

[@flastname560]

I just subbed. Why can't I save this video

[@TheNovaJohn]

Don't know, Ive never tried. KZbin never sent me a notification for your comment

[@lewiemcneely9143]

A-PLUS!

[@TheNovaJohn]

Thanx Lewie!

[@philliphall5198]

Someone needs to stamp out metal plate to go on it and tighten bolts up Maybe????

[@TheNovaJohn]

Not a bad idea, probably could print one an a printer in metal or even plastic!!

[@philliphall5198]

Yea. Take all the power tools away and get a racket

[@carl3233]

dont be cheap buy a new primer bulb .

[@TheNovaJohn]

Read some of the comments Carl,,some people have bought a new one and had the same issue. This is a quick and reliable repair as well. Its not always about being cheap! Thanx fer watchin!

[@jizzi2621]

Hi, Never! Ever! Ever! Use silicon on or around a carburetor , Period! This includes Auto, Lawn mower, anything that uses a carburetor...