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I have a B&S Model 31N707-0301-B2 engine that was sitting outside unused for two years in an MTD lawn tractor. It will start when gas is dribbled into the cylinder or carburetor mouth, but will only run until that tiny amount of fuel is consumed. I suspect I have a carburetor problem. Can anyone tell me what the "fuel Solenoid" does and how to test it? I thought I'd start there. Any other advice regarding the carb would be appreciated. I believe it is a Nikki.

Thanks very much...

Roger B

To the best of my knowledge the solenoid was mandated by the gument to aggravate the consumer. A usual test is to feel/hear the solenoid click to open when the ignition switch is turned to the first position (on) and shuttle to off with the ignition being turned off.

Hey Senior.. Glad to see I'm not the only old duffer around here...

So all the solenoid does is turn the fuel line on and off.. I guessed as much. I ought to be able to figure out if it's working without too much trouble. In working on the machine I haven't heard it make any noise, but I'll pay closer attention now.

Thanks,

Roger

https://www.briggsandstratton.com/n...nemanuals.html?searchrequested=31n707-0301-b2

you will need code number from engine for correct carburetor or kit

carburetor cleaner
https://www.amazon.com/Briggs-Stratton-796184-Carburetor-Overhaul/dp/B002WNT572 carburetor overhaul kit

https://www.amazon.com/Briggs-Stratton-794572-Carburetor-Replaces/dp/B005F6QJIQ new Nikki carburetor

Thanks Mark,

The engine code is 080227ZE.

Do you think taking the carb apart and cleaning with something like old fashioned Gumout or the newer Seafoam is worth the effort? I like to try easy things first.

Roger

Roger B said:

Hey Senior.. Glad to see I'm not the only old duffer around here...

So all the solenoid does is turn the fuel line on and off.. I guessed as much. I ought to be able to figure out if it's working without too much trouble. In working on the machine I haven't heard it make any noise, but I'll pay closer attention now.

Thanks,

Roger

Click to expand...

Almost but not quite.
The solenoid jambs a plug into the end of the main jet so even if the float bowl is full of fuel, none can get into the engine.
It is to prevent the engine pumping out unburned fuel between the time the spark stops and the engine stops rotating.
Apparently this will prevent the world as we know ceasing to exist.
Now think of it, around 50,000 mowers in the USA with an average capacity of 500 cc.
The engine does around 5 revolutions before it stops so that is 0.5 L x 5 x 50,000 = 125,000 liters of unburned fuel vapour ( about 2000 gallons) going into the atmosphere every week .
Oh lord save us from our sins
Or the same amount as 10 jets with 4 engines taking off .
Only they do it 10 times a day
Like a lawnmower is really gong to make a difference.

Ahhhhh Bert San... You question the validity of governmental decisions aimed at protecting us from ourselves? Certainly you know that 'they' have 'our' best interests at heart! . . . LOL...

Probably not a discussion we'd better get into or we will be asked to leave the Forum for creating a political s**t storm...

Actually if your figures are correct (and I have no doubt they are) then I guess there really is a measurable environmental benefit.. Not to mention the savings to the individual owners who save a tiny bit of fuel every time they shut down their machines...

My problem is, I have to figure out if the little bugger is actually working! (I haven't gone out to the shop yet this morning, being lazy...)

I'll let you know what I learn when I get into it, (if anything!)

Roger

Roger B said:

Ahhhhh Bert San... You question the validity of governmental decisions aimed at protecting us from ourselves? Certainly you know that 'they' have 'our' best interests at heart! . . . LOL...

Probably not a discussion we'd better get into or we will be asked to leave the Forum for creating a political s**t storm...

Actually if your figures are correct (and I have no doubt they are) then I guess there really is a measurable environmental benefit.. Not to mention the savings to the individual owners who save a tiny bit of fuel every time they shut down their machines...

My problem is, I have to figure out if the little bugger is actually working! (I haven't gone out to the shop yet this morning, being lazy...)

I'll let you know what I learn when I get into it, (if anything!)

Roger

Click to expand...

Roger I sent you this link in your other posts (starters)

http://outdoorpowerinfo.com/repairs/briggs_intek_single_ohv_nikki_carb.asp
you may find this helpful I also asked for the model # of your mower ( look under the mowers seat for a sticker )

Booba...

The Yardman is a Model 13AO772G055..

All is well! I got the engine running! I just cleaned out the carb where the fuel solenoid was screwed in and she runs like a clock.. (Well a 'rough' clock, but it runs.) Some debris got in the carb when the plastic cowling was removed from the engine.

Thanks for the help..

Roger

Roger B said:

Booba...

The Yardman is a Model 13AO772G055..

All is well! I got the engine running! I just cleaned out the carb where the fuel solenoid was screwed in and she runs like a clock.. (Well a 'rough' clock, but it runs.) Some debris got in the carb when the plastic cowling was removed from the engine.

Thanks for the help..

Roger

Click to expand...

Here's your operators and parts MANUALS ( I hope )

https://www.partstree.com/parts/mtd...r-2008-walmart/hood-control-assembly-762-772/

http://www.mtdproducts.com/equipmen...oCode=03&modelNumber=13AO772G055&serialNumber ..... (click on the PDF links in this one )

THIS should be your service MANUAL .....http://troybilt.custhelp.com/ci/fattach/get/108619/0/filename/769_06667_700_series_riders.pdf

" Hey Senior.. Glad to see I'm not the only old duffer around here..."

Any of you 84 or more?

"Probably not a discussion we'd better get into or we will be asked to leave the Forum for creating a political s**t storm..." (gov. regs.)

Right.

Walt Conner

Walt,

Nope... Not even 74 yet, but working on it... I didn't realize there was a cut off date... I guess I'm still just a youngster!! Yippeeeeeeeeeeeeeeeee!!

Roger

Boob-La....

I found the Yardman MTD manual! Thanks a million! I finally found a description of how all those safety switches work and was able to construct a wiring diagram.. Then I found a wiring diagram! At first the manual kept talking about a "OCR" module and that had me buffaloed as I hadn't seen anything like that. Then I discovered that my tractor has a "Standard Electrical System" (thank heavens) and everything fell into place after that. The only problem I have now (electrically, that is) are the headlights. They have no voltage to them. They should be on the same circuit as the fuel (after fire) solenoid. The wires are all enclosed in plastic wire loom, but I'll open that up and trace the wires down.

Thanks again for the manuals website, that is a great resource!

Roger

Roger B said:

Boob-La....

I found the Yardman MTD manual! Thanks a million! I finally found a description of how all those safety switches work and was able to construct a wiring diagram.. Then I found a wiring diagram! At first the manual kept talking about a "OCR" module and that had me buffaloed as I hadn't seen anything like that. Then I discovered that my tractor has a "Standard Electrical System" (thank heavens) and everything fell into place after that. The only problem I have now (electrically, that is) are the headlights. They have no voltage to them. They should be on the same circuit as the fuel (after fire) solenoid. The wires are all enclosed in plastic wire loom, but I'll open that up and trace the wires down.

Thanks again for the manuals website, that is a great resource!

Roger

Click to expand...

Hey Rog, ...gettin hard to keep up with 3 threads ya got goin, I guess you got all the info I sent (posted) ....some on this thread ,some on that one ,P.M.s etc. etc. ( LOL ) I guess the carb. & eng. are on the back burner for now, as far as the headlights....... I don't know anybody that uses them... UNLESS they rigged up a powerful set of aftermarket lights.
Now about that tranny....... I had no idea MTD made their own trannys, seems in one case there are more than a hundred different models using the same trans. among their different brands / models, MTD, WHITE, YARD MACHINES, YARD MAN, etc. etc. I have'nt found a parts cross-reference manual and when you check the aftermarket sites you can find many different trans numbers that supersede or replace other numbers....... some prices, are reasonable, and I think putting that kind of money ( over $200.00 ) into an older used machine for 1 part is going overboard, consider a used tranny first, but that's risky too. Are you sure the trans IS bad ??? if not.... it could be linkage or some other problem. I think you should check the service manual, (hope it was the right one ) make sure you determine the type of trans you have and if you think you can repair it yourself, looking in the parts manuals ( partstree.com) --(ereplacementparts.com) the parts , even the housings did'nt seem overly expensive, you may want to give yourself a "project" ( LOL ) Lastly ( for-now) Not tryin to "blow out your candle" but.. you MIGHT ... consider putting the engine on a different used mower... it might actually be cheaper if you can find a used cheap unit , AND what condition is your deck in ???... ( ut-oh ) another thread ???.. (LOL ) Hell Rog... I'm writing a book here..... I better get outa here , later buddy ....... Boobala ..:wink:

Boob-La...

Man you got that right! There seems to be a million different transaxles from a million different lawn tractors! A cross reference guide would be as thick as a NYC phone book!

Currently I'm leaning towards repair.. Someone suggested having the crack in the upper housing welded and after studying the manual you hooked me up with, I can see there are replaceable bushings at the ends of the axle. Assuming the gearing inside is all good, then having the housing welded would most likely be fairly inexpensive and the axle opening at the end of the housing, (which is current worn into an egg shape) could have any extra weld that came though rough ground out and then maybe finished smooth with 'liquid steel' and a new bushing installed.. As soon as the mood strikes me, I'm going to reread the manual on transaxle disassembly and take it apart.. I'll let you know how that goes.. Hey at the very worst, I'll end up with a bench covered with lots of parts.. right?

Roger

Roger B said:

Boob-La...

Man you got that right! There seems to be a million different transaxles from a million different lawn tractors! A cross reference guide would be as thick as a NYC phone book!

Currently I'm leaning towards repair.. Someone suggested having the crack in the upper housing welded and after studying the manual you hooked me up with, I can see there are replaceable bushings at the ends of the axle. Assuming the gearing inside is all good, then having the housing welded would most likely be fairly inexpensive and the axle opening at the end of the housing, (which is current worn into an egg shape) could have any extra weld that came though rough ground out and then maybe finished smooth with 'liquid steel' and a new bushing installed.. As soon as the mood strikes me, I'm going to reread the manual on transaxle disassembly and take it apart.. I'll let you know how that goes.. Hey at the very worst, I'll end up with a bench covered with lots of parts.. right?

Roger

Click to expand...

Yeah Rog, I was going banannas clickin on the different models ,looking at their parts list for other trans #s .... I can't believe the way MTD does their parts numbers, I can see why they may not have a cross reference manual. Someone really screwed up that mess, (and I USED to think the manuals I used in the military were insane) I'm thinking you may have to call MTD support for info on what trans to use. Let me suggest ...... ANYTHING ... ANYTHING you work on ........ take tons of pictures .... (hope ya have a digital camera) its a lifesaver during re-assembly ..... check -out my picture albums ( my project & project 2 ) on my profile page , you can always delete them later , many times it has saved my "sit-down" .......at my age I can't remember all this stuff ( brain overload ya know ) ..:confused2: take pics all the way through... you will thank yourself for making your own manual, it really works ! By the way .... it's great workin with ya , thanks for the up-dates, work SAFELY and don't go stickin any knife blades in the receptacles ..:laughing: ..:laughing: ..later good buddy ...Boobala

http://www.mtdproducts.com/equipmen...Code=05&modelNumber=13AO772G055&serialNumber=

just information

Thanks Mark,

I've been using that site... Inside the tranny now... it's yucky to say the least and badly cracked and worn too!

Roger

COMING ATTRACTIONS !!!

just to up-date this thread..... Roger B ...... has performed the necessary repairs to the transaxle of his Yard-Man mower ..... currently he is creating havoc & mayhem in the Central Florida area while taking his annual getaway,... However upon his return
to the frozen tundras of Maine, ..... He will once again renew this thread ......related to his carburetor situation.
May we all wish Roger & wife a safe journey home as we prepare our libraries of knowledge to assist him in the
forthcoming " Battle of Beating the Briggs Carburetor " feature .... Ya'll have a good day now ... ya hear ?? ..:cool2:

P.S. If anyone knows how to turn a riding lawnmower into a "looks like a submarine to me" ideas .... please be ready to put them on the agenda ...as always .... your advice & comments are ALWAYS more than welcome ! .. Boobala .. ..:laughing:

Boobala said:

COMING ATTRACTIONS !!!


May we all wish Roger & wife a safe journey home as we prepare our libraries of knowledge to assist him in the
forthcoming " Battle of Beating the Briggs Carburetor " feature .... Ya'll have a good day now ... ya hear ?? ..:cool2:

Click to expand...

Boo-Boo,

You're too good to me.. What did I ever do to earn your undying help and assistance?

Hey! Bert-Man tells me there is a "front (or back) porch" place for generalizations and wanderings.. (Which we seem to have a tendency to do - well me anyway..) Maybe we could generate a new thread there and attract some additional contributors... Wha'Cha think about that???

bertsmobile1 said:

Almost but not quite.
The solenoid jambs a plug into the end of the main jet so even if the float bowl is full of fuel, none can get into the engine.
It is to prevent the engine pumping out unburned fuel between the time the spark stops and the engine stops rotating.
Apparently this will prevent the world as we know ceasing to exist.
Now think of it, around 50,000 mowers in the USA with an average capacity of 500 cc.
The engine does around 5 revolutions before it stops so that is 0.5 L x 5 x 50,000 = 125,000 liters of unburned fuel vapour ( about 2000 gallons) going into the atmosphere every week .
Oh lord save us from our sins
Or the same amount as 10 jets with 4 engines taking off .
Only they do it 10 times a day
Like a lawnmower is really gong to make a difference.

Click to expand...

Bert, I do always appreciate your somewhat alternate view on these matters...
I was of the impression that the solenoid prevented fuel from entering the engine, passing thru it unburned into the muffler,
where it would ignite in a rather annoying POP !

Roger B said:

Boo-Boo,

You're too good to me.. What did I ever do to earn your undying help and assistance?

Hey! Bert-Man tells me there is a "front (or back) porch" place for generalizations and wanderings.. (Which we seem to have a tendency to do - well me anyway..) Maybe we could generate a new thread there and attract some additional contributors... Wha'Cha think about that???

Click to expand...

I came ... I saw ....I posted .... Probably will get bounced off the thread or site for my "brash" remarks !!!
Daffodils ... pansy's ...pansies .... poofballs !!! Ha,Ha, Ha, .............. :laughing: ..:laughing: ..:laughing:..:cool2:

Ronno6 said:

Bert, I do always appreciate your somewhat alternate view on these matters...
I was of the impression that the solenoid prevented fuel from entering the engine, passing thru it unburned into the muffler,
where it would ignite in a rather annoying POP !

Click to expand...

They called it an ant-afterfire solenoid because of what you said.
However they were compulsory in Cal .
I buy a lot of engines from the USA and the ones marked "Illegal for use in Cal" do not have the solenoid so that puts pay to that bull dust dosent it.
About 3/4 of the mowers sold down here do not have the solenoid fitted.
However they are compulsory in clean green ACT .

bertsmobile1 said:

They called it an ant-afterfire solenoid because of what you said.

Click to expand...

I can say from personal experience that they do prevent that annoying afterfire.............

Ronno6 said:

I can say from personal experience that they do prevent that annoying afterfire.............

Click to expand...

And so does throttleing down before you shut down which is what you were told to do before they were fitted or turning off the fuel at the tap and starving the engine off.
They are an EPA regulation but to make them "acceptable" to Joe Public they pretend there is a benefit to the user.
Down here they go for $ 150 to $ 75 ( Aus) and at that price are more expensive than some of the carbs they sit on.
Thus most home owners will just rip the !&@#$%@#$!# thing off when they cause troubles.

bertsmobile1 said:

And so does throttleing down before you shut down which is what you were told to do before they were fitted or turning off the fuel at the tap and starving the engine off.
They are an EPA regulation but to make them "acceptable" to Joe Public they pretend there is a benefit to the user.
Down here they go for $ 150 to $ 75 ( Aus) and at that price are more expensive than some of the carbs they sit on.
Thus most home owners will just rip the !&@#$%@#$!# thing off when they cause troubles.

Click to expand...

I'm sorry, but I must disagree.
Not only would I throttle down to idle, but I would also shut off a pet cock which I installed in the fuel line.
After closing the fuel valve, I would idle the engine a moment to tale pressure off the needle/seat inlet.
I would still get the annoying afterfire even after that procedure.

Nobody ever "told" me to slow to idle before turning off the ignition...it is just common sense.........

Ronno6 said:

I'm sorry, but I must disagree.
Not only would I throttle down to idle, but I would also shut off a pet cock which I installed in the fuel line.
After closing the fuel valve, I would idle the engine a moment to tale pressure off the needle/seat inlet.
I would still get the annoying afterfire even after that procedure.

Nobody ever "told" me to slow to idle before turning off the ignition...it is just common sense.........

Click to expand...

Sorry Ronno
I have to agree with bert...... I have 2 mowers, .. both with the 17.5 HP Briggs engines each with the Nikki carb.
each has the solenoid... which operates as they should... yet on occasion ..... whether I idle down for a short period or throttle -up while shutting-down, I get the shot-gun pop which puts the neighbors cat ..up the tree !! I 'm thinking the solenoid is actually there to prevent a hydro-lock of the engine in case the needle valve becomes stuck in the open position and allows fuel to enter the engine.. in any case if & when mine fail ... they will NOT be replaced ..Boobala

Boobala said:

Sorry Ronno
I have to agree with bert...... I have 2 mowers, .. both with the 17.5 HP Briggs engines each with the Nikki carb.
each has the solenoid... which operates as they should... yet on occasion ..... whether I idle down for a short period or throttle -up while shutting-down, I get the shot-gun pop which puts the neighbors cat ..up the tree !! I 'm thinking the solenoid is actually there to prevent a hydro-lock of the engine in case the needle valve becomes stuck in the open position and allows fuel to enter the engine.. in any case if & when mine fail ... they will NOT be replaced ..Boobala

Click to expand...

No need to apologize.
Our experiences differ.
YMMV...........

The thing is Boobala the solenoid will not stop a hydrolock because it cannot prevent fuel overflow through the carb bowl vent into the venturi if the float valve sticks open. Most of the time it will stop the afterfire bang, but not all the time. Kohler says shut there engines off at full throttle because the design of the carb prevents the solenoid from shutting off the fuel flow on the idle circuit, only the high speed jet.

I have a customer that has a Toro that didn't matter what you did would still afterfire. A few years ago I had to install a new engine on that mower due to a valve dropping into the cylinder while it was running. Started the new engine up, and got it to operating temp, let it idle for about 30 seconds, and shut it off to the nice little bang. the only thing that wasn't replaced with the engine swap was I had to reuse the muffler. In this case the muffler is the problem that is allowing the afterfire.