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Bolens Garden tractor with Walbro LMT-4993 carb issues

#1

bcolins

bcolins

I am trying to help a friend get an old Bolens Lawn mower/tractor running. It would start then die,....seemed like a fuel supply issue. I removed the carb, its a Walbro 4993 with a Briggs and Stratton logo on it, also LMT and the number 77. I decided to clean it up with some brake clean and look for Identification on it and see if I could find a rebuild kit. Some numbers on the valve cover as well, See picture below.

Once I got it clean I removed the fuel bowl and found it had a fair amount of dirt or corrosion flakes in it. Also some of the internal bits looked a bit corroded, maybe water in the old gas? I looked up Walbro 4993 on Google and saw several Walbro LMT 5-4993 carbs for about $15 (new with shipping included) that appear to be the same visually,.....wondering if anyone can tell me if the 5-4993 will replace the older LMT 4993, or if this one can be saved.

Picture of the valve cover with engine numbers below,....the carb picture is too big to attach here but I was able to upload it to the "Photos" section listed at the top of the page. Album is called "Bolens Walbro Carb pics"

Link: https://www.lawnmowerforum.com/media/albums/bolens-walbro-carb-pics.7366/


BC in Austin

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#2

StarTech

StarTech

First the Walbro LMT 5-4993 casting number is just the base carburetor before being properly jetted for your engine.

Briggs 791888 is a gravity fed carburetor and has been superseded to 594593. Using this new part number you can find a cheap after market Walbro carburetor. Just beware that these after market carburetors are problematic. The OEM carburetor listed at $120. A good shop mechanic can re-jet the carburetor but that is something has to be done in the shop where they have the correct tools.

To me most DIYers are gamblers and will go for the lowest priced carburetor and then bitch like hell when the engine don't run right.

Just note that most times the original carburetor is repairable. But in your case there have been water sitting in the fuel bowl and the fuel solenoid is likely damaged too.


#3

bcolins

bcolins

StarTech said:
First the Walbro LMT 5-4993 casting number is just the base carburetor before being properly jetted for your engine.

Briggs 791888 is a gravity fed carburetor and has been superseded to 594593. Using this new part number you can find a cheap after market Walbro carburetor. Just beware that these after market carburetors are problematic. The OEM carburetor listed at $120. A good shop mechanic can re-jet the carburetor but that is something has to be done in the shop where they have the correct tools.

To me most DIYers are gamblers and will go for the lowest priced carburetor and then bitch like hell when the engine don't run right.

Just note that most times the original carburetor is repairable. But in your case there have been water sitting in the fuel bowl and the fuel solenoid is likely damaged too.
Click to expand...
I found a Walbro 594593 carb on Amazon for $15 from "Carbman", figured it was worth a shot, if it doesn't work,...I'm only out $15.


#4

F

Forest#2

Here is a link to tips about LMT carbs.
https://outdoorpowerinfo.com/repairs/

Them old LMT carbs usually re-build and clean up Ok.
Try cleaning at first without removing the emulsion tube.
A proper fitting hollow ground screwdriver is required to fit the emulsion tube or it can be damaged easily.
The replacement carbs are Nikki type clones and it's a roll of the dice to get a good smooth operation.

I've seen used Walbro LMT's on fleece bay for around $20.
You also need to install a red fuel filter and a petcock.

Read #2 post again also.


#5

M

mechanic mark

Results

www.briggsandstratton.com www.briggsandstratton.com
www.briggsstrattonstore.com

697241 Briggs and Stratton Kit-Carb Overhaul OEM

Get the best priced BRIGGS & STRATTON Carb Overhaul Kit 697241 with top stock, fast shipping, and quality assurance. Order now for quick delivery!
www.briggsstrattonstore.com www.briggsstrattonstore.com


#6

bcolins

bcolins

I have tried to remove the emulsion tube a few times with a properly fitting screw driver bit, have let it soak in PB Blaster, and it is still seized or frozen in the carb.


#7

F

Forest#2

You usually only get one shot with a screwdriver when trying to remove the emulsion tube from a Walbro LMT.

AND
the majority of them so called replacement LMT carb's are not really Walbro LMT, they are a Nikki LMT clone and do be SURPRISED if you get a good running smooth one.
If buying from Amazon Prime you can keep returning until you maybe get one you can live with.
Every once in awhile a real Walbro LMT will surface on fleece bay at a reasonable price.
Sometimes (as a last ditch effort) lots of high pressure air through a stuck in place LMT emulsion tube will get a good run after it's been soaked awhile.


#8

bcolins

bcolins

Forest#2 said:
You usually only get one shot with a screwdriver when trying to remove the emulsion tube from a Walbro LMT.

AND
the majority of them so called replacement LMT carb's are not really Walbro LMT, they are a Nikki LMT clone and do be SURPRISED if you get a good running smooth one.
If buying from Amazon Prime you can keep returning until you maybe get one you can live with.
Every once in awhile a real Walbro LMT will surface on fleece bay at a reasonable price.
Sometimes (as a last ditch effort) lots of high pressure air through a stuck in place LMT emulsion tube will get a good run after it's been soaked awhile.
Click to expand...
Not familiar with fleece bay


#9

F

Forest#2

You say:
Not familiar with fleece bay

You are a rare breed if you have not experienced fleece bay.
Just type into the search bar what you are looking for and you can do a SAVED search so as to get a email notice if whatever you are seeking appears later.
try this link. (and keeps a heads up about sellers feedbacks, etc.)
www.ebay.com

Electronics, Cars, Fashion, Collectibles & More | eBay

Buy & sell electronics, cars, clothes, collectibles & more on eBay, the world's online marketplace. Top brands, low prices & free shipping on many items.
www.ebay.com


#10

bcolins

bcolins

Forest#2 said:
You say:
Not familiar with fleece bay

You are a rare breed if you have not experienced fleece bay.
Just type into the search bar what you are looking for and you can do a SAVED search so as to get a email notice if whatever you are seeking appears later.
try this link. (and keeps a heads up about sellers feedbacks, etc.)
www.ebay.com

Electronics, Cars, Fashion, Collectibles & More | eBay

Buy & sell electronics, cars, clothes, collectibles & more on eBay, the world's online marketplace. Top brands, low prices & free shipping on many items.
www.ebay.com
Click to expand...
OH! eBay! sorry, didn't make the connection. Why "Fleece"? Isn't fleece a kind of wool fabric for clothing?


#11

F

Forest#2

bcolins said:
OH! eBay! sorry, didn't make the connection. Why "Fleece"? Isn't fleece a kind of wool fabric for clothing?
Click to expand...


verb
  • 1.obtain a great deal of money from (someone), typically by overcharging or swindling them:


#12

bcolins

bcolins

Forest#2 said:
verb
  • 1.obtain a great deal of money from (someone), typically by overcharging or swindling them:
Click to expand...
Hmmm, I have always felt ebay prices were fair when purchasing something. (or I simply don't buy that item) and I have done over 400 transactions on eBay,....mostly purchases.


#13

G

Gord Baker

Duh!


#14

StarTech

StarTech

You really got to be careful buying from eBay as some items are "HOT". Probably why some my postal shipments disappear in route. Just had $250 in bearings to diappear in the Memphis post office two weeks ago. Matter of fact the Memphis PO has a very bad record of handling packages.


#15

M

mowermaint

bcolins said:
I am trying to help a friend get an old Bolens Lawn mower/tractor running. It would start then die,....seemed like a fuel supply issue. I removed the carb, its a Walbro 4993 with a Briggs and Stratton logo on it, also LMT and the number 77. I decided to clean it up with some brake clean and look for Identification on it and see if I could find a rebuild kit. Some numbers on the valve cover as well, See picture below.

Once I got it clean I removed the fuel bowl and found it had a fair amount of dirt or corrosion flakes in it. Also some of the internal bits looked a bit corroded, maybe water in the old gas? I looked up Walbro 4993 on Google and saw several Walbro LMT 5-4993 carbs for about $15 (new with shipping included) that appear to be the same visually,.....wondering if anyone can tell me if the 5-4993 will replace the older LMT 4993, or if this one can be saved.

Picture of the valve cover with engine numbers below,....the carb picture is too big to attach here but I was able to upload it to the "Photos" section listed at the top of the page. Album is called "Bolens Walbro Carb pics"

Link: https://www.lawnmowerforum.com/media/albums/bolens-walbro-carb-pics.7366/


BC in Austin
Click to expand...
I suspect that you are the victim of ethanol bad fuel. As others have mentioned you may be able to clean it and fix it but sometimes its just not possible. If you get a new one fortunately there are non-ehtnanol suppliers in your area. Worth every penny.


#16

M

mowermaint

Forest#2 said:
Here is a link to tips about LMT carbs.
https://outdoorpowerinfo.com/repairs/

Them old LMT carbs usually re-build and clean up Ok.
Try cleaning at first without removing the emulsion tube.
A proper fitting hollow ground screwdriver is required to fit the emulsion tube or it can be damaged easily.
The replacement carbs are Nikki type clones and it's a roll of the dice to get a good smooth operation.

I've seen used Walbro LMT's on fleece bay for around $20.
You also need to install a red fuel filter and a petcock.

Read #2 post again also.
Click to expand...
One gotcha I've encountered with add on fuel filters is that sometimes the fuel pump on the motor is not adequate to keep fuel running thru the filter when under load. I've encountered this on a kawasaki/JD mower and a generaq generator. Now maybe the mistake I made was using a cheap inline filter, in any case I just removed the filter as I figured I was trying to solve a problem I didn't really have.


#17

F

Forest#2

mowermaint said:
One gotcha I've encountered with add on fuel filters is that sometimes the fuel pump on the motor is not adequate to keep fuel running thru the filter when under load. I've encountered this on a kawasaki/JD mower and a generaq generator. Now maybe the mistake I made was using a cheap inline filter, in any case I just removed the filter as I figured I was trying to solve a problem I didn't really have.
Click to expand...
Briggs has a red colored fuel filter for engine that are for gravity feed and white fuel filters for pump feed. The white is a finer micron filter and will sometimes not let enough gas flow when installed on gravity fed.
Also the Briggs white will get restricted faster if the fuel/tank is dirty.
Yes, his carb looks like his carb has stage 4 cancer from ethanol/water contamination.


#18

L

LMPPLUS

bcolins said:
I am trying to help a friend get an old Bolens Lawn mower/tractor running. It would start then die,....seemed like a fuel supply issue. I removed the carb, its a Walbro 4993 with a Briggs and Stratton logo on it, also LMT and the number 77. I decided to clean it up with some brake clean and look for Identification on it and see if I could find a rebuild kit. Some numbers on the valve cover as well, See picture below.

Once I got it clean I removed the fuel bowl and found it had a fair amount of dirt or corrosion flakes in it. Also some of the internal bits looked a bit corroded, maybe water in the old gas? I looked up Walbro 4993 on Google and saw several Walbro LMT 5-4993 carbs for about $15 (new with shipping included) that appear to be the same visually,.....wondering if anyone can tell me if the 5-4993 will replace the older LMT 4993, or if this one can be saved.

Picture of the valve cover with engine numbers below,....the carb picture is too big to attach here but I was able to upload it to the "Photos" section listed at the top of the page. Album is called "Bolens Walbro Carb pics"

Link: https://www.lawnmowerforum.com/media/albums/bolens-walbro-carb-pics.7366/


BC in Austin
Click to expand...
It's the luck of the draw on a Amazon / Ebay product there's no quality control, doesn't seem to be an actual cross to a decent after market carb, but there are some that might work. Good luck


#19

bcolins

bcolins

I received the carb, gasket, filter, hose and clamps,....also recieved the items shown in the pic below that I do not recognize ( of course I recognize the screw, but don't recall having a self tapping screw somewhere,.....maybe for a different application?) ,....also one of which appears to be a tool possibly for reaming jets to different sizes. Thoughts?

Attachments





#20

S

slomo

E-pray is more like it. Most parts are junk.


#21

bcolins

bcolins

I doubt the owner of the mower that I am trying to help out ever did this,...but we spoke about this exact thing a week or so ago.


#22

F

Forest#2

bcolins said:
I doubt the owner of the mower that I am trying to help out ever did this,...but we spoke about this exact thing a week or so ago.
Click to expand...

???????????
Are you referencing having a prayer meeting before installing the new carb?????
If so, that would be a good idea.


#23

bcolins

bcolins

Forest#2 said:
???????????
Are you referencing having a prayer meeting before installing the new carb?????
If so, that would be a good idea.
Click to expand...
Pretty funny,.....no,....referring to cleaning the fan and shroud.


#24

StarTech

StarTech

bcolins said:
I received the carb, gasket, filter, hose and clamps,....also recieved the items shown in the pic below that I do not recognize ( of course I recognize the screw, but don't recall having a self tapping screw somewhere,.....maybe for a different application?) ,....also one of which appears to be a tool possibly for reaming jets to different sizes. Thoughts?
Click to expand...
One item cutting torch tip cleaners. Some use to clean the orifices of the carbs but I would not use them as they can enlarge jets. The big item is a manual choke add-on lever. I never need it.

Now the torch tips cleaners I can as I have a cutting ace/ox torch here.

And one last item in the pic mixture adjust limiter cap for the mixture screw once it is set.


#25

L

Lord_Cavendish

slomo said:
E-pray is more like it. Most parts are junk.
Click to expand...
Flea-bay, lots of junk but you can find decent parts at better than Crapazon prices. Crapazon is junk at a higher price, and more of the china variety crap.


#26

F

Forest#2

I suspect that long plastic piece is a choke lever if the carb was to be used on a Emergency gen engine. (their carb chole levers looks like that because the air filter breather is bolted to the front of the carb and the lever sticks up from behind the breather.
You got lucky that the plastic choke lever was not installed on the carb as the only choke. (some repl carbs come with only that one lever for use with the emergency gen engines and the lawn tractor chole lever is not offered separately.

Maybe the carb gods are starting to shine a little bit of light/luck on You.


#27

bcolins

bcolins

Good News!
StarTech said:
First the Walbro LMT 5-4993 casting number is just the base carburetor before being properly jetted for your engine.

Briggs 791888 is a gravity fed carburetor and has been superseded to 594593. Using this new part number you can find a cheap after market Walbro carburetor. Just beware that these after market carburetors are problematic. The OEM carburetor listed at $120. A good shop mechanic can re-jet the carburetor but that is something has to be done in the shop where they have the correct tools.

To me most DIYers are gamblers and will go for the lowest priced carburetor and then bitch like hell when the engine don't run right.

Just note that most times the original carburetor is repairable. But in your case there have been water sitting in the fuel bowl and the fuel solenoid is likely damaged too.
Click to expand...
UPDATE: I finally got around to installing the carbman carb that I found on Amazon using the 594593 part number you referenced. A few sprays of Starting fluid, and it fired right up and ran on the carb. Runs better than when he bought the mower according to the owner. Thanks for the helpful information StarTech.

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