# B&S 12 HP Problem



## johnjr22000 (Jun 1, 2006)

Any ideas on the below problem?
Engine runs great for about 30 minutes. Then is will start to run rough. Then it will start to die when going up a slight incline. I can choke it to keep it running. If I turn and go down the incline the engine will run, but rough.

thanks


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## peppy (Jul 19, 2006)

Sounds like the float is sticking


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## johnjr22000 (Jun 1, 2006)

I don't know much about carbs....
How do I fix this? Cleaning?


thanks


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## kbalona (Apr 27, 2006)

yeah take the carb apart & inspect the float & needle. might as well spray it up with carb cleaner while it's apart, if you can get some. make sure the jets are clean. If there's a lot of crap in it you might want to consider a carb rebuild.


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## peppy (Jul 19, 2006)

You will be looking for something similar to this:








Just follow the fuel like down and the dead giveaway will be the fuel bowl.
When you remove the bowl, you will see the float. The float assembly pivot on a shaft. As the fuel rushes into the bowl the float starts to rise and pushes the float needle into the seat. When to fuel level reaches the proper height the needle and seat shut off the flow of fuel. Drain out all the fuel first from the tank. When you remove the bowl, there will be a little bit of fuel in it. DO NOT LET THE FLOAT SWING OUT WHEN YOU REMOVE THE BOWL. 









Clean out the bowl and also take a look at the float and make sure it is not weighted down by holding fuel inside of it. Clean the bowl as much as much as possible and reassemble. If this doesnt work, you probably will need a new carb kit.


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## 2mcgrath (Oct 10, 2003)

also could you by chance have water in your fuel?


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## Fortune50 (Aug 28, 2006)

johnjr22000 said:


> Any ideas on the below problem?
> Engine runs great for about 30 minutes. Then is will start to run rough. Then it will start to die when going up a slight incline. I can choke it to keep it running. If I turn and go down the incline the engine will run, but rough.
> 
> thanks


Does it always run fine and then after a while it begins to run rough? Before taking the carb apart, take off the gas tank's cap and see how it runs, if it runs better, then clean the cap's vent holes or get a new cap. If it still runs badly, then take out the spark plug and look to see if it's looks like the engine has been running lean (whitish deposits). If the engine appears to be running lean, then I'd consider perhaps that the fuel is vaporizing inside the carb from an overheating engine. Take off the engine cover and be sure the engine's cooling fins are clear and unobstructed. Be sure the flywheel's fins & screen cover are also clear. Then if everything checks out there, then start tearing into the carb. It just seems like that if the carb is plugged, the engine would be harder to start cold (or wouldn't start unless using starting fluid )and once running you'd have to ALWAYS have to keep the choke on...


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## johnjr22000 (Jun 1, 2006)

Thanks for all your help.
I tried the gas cap and made sure everything was clean and the problem was still happening. How does the needle go back in?
Does anyone have instructions for rebuilding the carb?
Briggs modle 28v707 type 1113-e1 KMT carb.


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## Fortune50 (Aug 28, 2006)

johnjr22000 said:


> Thanks for all your help.
> I tried the gas cap and made sure everything was clean and the problem was still happening. How does the needle go back in?
> Does anyone have instructions for rebuilding the carb?
> Briggs modle 28v707 type 1113-e1 KMT carb.


So, the spark plug has whitish deposits on it? If so, then the carb is probably plugged and needs cleaning. Before tearing it apart, drain the gas out of the tank and the fuel bowl (remove bolt & washer on bottom of fuel bowl), then reinstall the float bowl bolt & washer and pour Seafoam brand of fuel system cleaner into the gas tank and let it fill up the carb bowl, start it up for a little bit to let the carb absorb the cleaner into the fuel nozzle & jets and then shut it off. Let it sit overnight. Then the next day, just add gas to the gas tank and start it up to see it it'll run better. I've had good luck with that stuff, it's allowed me to hold off on carb rebuilds by several years, lol. One more thing, if you decide to try and rebuild it, the parts guide on your engine model & type I've got shows that your carb choices are either Walbro or Nikki. If it's a Nikki, the name Nikki should be stamped on the side of the carb were the fuel inlet line is located. And the carb rebuild kit should have an exploded view of it's parts as a guidline on taking it apart and reassembling it as well as float specs. If no float specs are included, then measure the old one to get an approximation of where the new one should be set to. Also, you can ask the shop for all the specs on your carb from their shop manual, too. It's only fair since you're buying the kit from them. :thumbsup: Good luck to you and keep us posted. :wave:


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## johnjr22000 (Jun 1, 2006)

Thanks for all the help.
Does anyone have a shop manual on the b&s model 28v707 type 1113-e1 in pdf format that can be emailed to me? I received the carb kit in the mail and I would love to have the manual for when I run into problems. The carb on my engine is the Walbro.
When I took the carb apart I noticed the needle tip was rubber and it was stretched. I think replacing the needle valve seat and needle will do the trick.
It looks very simple but some things are not clicking for me and I am visual.
Example, how does the needle sit in the seat? Does it slide into the lip on the float? Fortune 50 mentioned float specs; nothing came with the carb kit.

My email is [email protected]

thanks again


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## TechLarry (Aug 2, 2006)

If I may make a suggestion...

Take your digital camera, and take many, many pictures.

That's what I did. I started with it on the tractor, pictures of all the linkages and where they went, EVERYTHING! Especially the governer/throttle control stack on the Command 18 on my CC 1864, which is a mechanical asshole if there ever was one.

Once on the bench, I took a picture of the carb on all sides, top, bottom, eveywhere.

Then, just before removing a part or screw, I took another picture of that area. A picture for every piece I removed.

I have about 50 pictures of my removal, rebuild, reinstall process 

I wish we had these DC's back when I was a car mechanic in the 70's. Anyone that has ever replaced a water pump on a 70's ford with Air Conditioning remembers the dozen little brackets, supports, dozens of bolts, etc... that you ended up with on the work bench after tear-down knows exactly what I mean. It was Ford's equivelent of a Rubiks Cube 

-Larry


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## Fortune50 (Aug 28, 2006)

TechLarry said:


> If I may make a suggestion...
> ...Anyone that has ever replaced a water pump on a 70's ford with Air Conditioning remembers the dozen little brackets, supports, dozens of bolts, etc... that you ended up with on the work bench after tear-down knows exactly what I mean. It was Ford's equivelent of a Rubiks Cube
> 
> -Larry


My very first car project was a '73 Gran Torino w/ the 302 engine. It had a bad waterpump, and needless to say, it took me a LONG time to get that done, good thing it was before I had my license, lol. My next small block Ford project was about 2 yrs. later replacing a timing chain/gears on a '75 Granada with a factory 351W, it had a smog pump whereas the Torino didn't, now that was a busy engine bay  .


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## johnjr22000 (Jun 1, 2006)

I cleaned and rebuilt the carb and she is running like brand new.
Thanks to all for your help.

john


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## kbalona (Apr 27, 2006)

Great, glad it's working. 
That DC thing is definitely a good idea if you don't have any manual.
It's not a good feeling when you put something back together and there's some bolts left over... :drunk:


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