What's wrong with my motor ?????

[bustedglass 1]

Hi Guys,

If you have been following my threads regarding my little B211-3, you know that I replaced the tired 11 h.p. B/S Vert. with a new/used 12.5 h.p. B/S Vert.

The little tractor with the new engine was running great . Then, all of a sudden, the engine started pulsating .

I thought that it might need a carb adjustment, but I soon found out, that the Walbro carb. on the engine does not have any adjustment screws. There is one screw/spring on the side of the carb just above the gas enlet. But I can turn this screw in/out, and nothing happens.

I think that I might have a governor problem, but I don't have a clue of how to adjust it, if there is an adjustment.

Remember, I have my exaust stack. Should I take it off, and put the stock muffler back on ?

This thing was running great, and now this. Help, Help, HELP.............

[kj4kicks 154]

Did they replace ALL the fuel lines?

On a scarier note, does the tractor stay locked up at all times? maybe somebody added something to your gas tank...

[bustedglass 1]

Hi Eldon,

Ya, all lines were replaced, and yes, it is locked in my shed when I am not using it. But, thanks for the brainstorming.........

[TT-(Moderator) 1,162]

The fellow at my local shop claims the newer Briggs are very sensitive with the air filters. If yours is new, disregard this idea..... but if it's not, try a new air filter.

If the filter is good, then maybe the governor arm slipped on the shaft, or the spring/linkage might be causing the surging.

You might also have a little dirt in the float needle/seat. B)

[rocking 416 1]

i would investigate throttle shafts . Check them for play . does it use a fuel pump? B)

[Teddy da Bear 11]

I practically got linched on another site for giving my opinion on this subject.

But hey! I am what I am!

I am going through the same problem on a Tecumseh engine. The problem?

The United States government regulations on small engines!

They have so directed how things be regulated for emissions that we ended up with carburators that have no adjustment and are "designed" to run "lean" for emissions standards. The only problem with a lean burning engine is that "lean' might be good for emissions, but flat out "sucks" for a good running motor!

The guy I knew went through his carburator with a small drill set and "opened up" the holes drilled in it at the factory, to the next nominal drill size. Then the motor ran like it should.

The only other solution is to find an old style adjustable carburator that will fit on your newer engine. Then you can tune it to suit yourself.

[DMESS 24]

The fellow at my local shop claims the newer Briggs are very sensitive with the air filters. If yours is new, disregard this idea..... but if it's not, try a new air filter.

If the filter is good, then maybe the governor arm slipped on the shaft, or the spring/linkage might be causing the surging.

You might also have a little dirt in the float needle/seat.

My Honda powered Lawn Boy is this way. As soon as the air filter starts getting just a little bit dirty it starts to surge and run rich. Let it go long enough and it will foul the plug. Best practice for it is a clean filter and plug each season and it's good to go. I've yet to tear it apart, but I'll assume it is a factory set carb as well.

[bambooheels 0]

i would also tend to think tat the spring linkage is not correct or the governor slipped, either both very easy fixs. good luck and i also agree that these rediculopus governemnt standards for fuel is crazy! didnt mind selling all thos SUV's for the last 2 decades though did they? :imstupid:

[bustedglass 1]

Hi bambooheels,

If the governor arm did slip, what is the correct setting for it ???

[bambooheels 0]

my understanding is that with the engine off you throttle the engine to fast speed, why your doing that the gov arm will move in one direction, witchever tha is you want to hold the nipple there and then move the arm to that direction as well, then tighten down, this shoiuld do it. i hop ethat helps B)

[bustedglass 1]

Thanks bambooheels, I will give it a try......

[bambooheels 0]

B) hey i was wondering if the governor was fixed, was that the problem? i hope it all worked out for you please update me.

[bustedglass 1]

Hi bambooheels,

Nope, was'nt the governor. Still have the problem. I am pulling my hair out - don'nt know what to do. If I play with the fast / slow arm till it is running so rich it is about to choke out, it will tend to run smoother. But, by this time, it is running so rich, the fumes are more than you can stand .

Wish I knew what to do with this thing .

[TT-(Moderator) 1,162]

Did you drop the float bowl off the carb and check for dirt in the needle & seat, Mike?

Close the fuel valve at the tank, remove the bowl and hold up on the float with your fingers while turning the fuel valve back on. If gas still comes through the inlet, there's dirt. Make sure the float level is set correctly while you have the bowl off.

Did you try running it without an air filter installed?

How about checking the flywheel key?

[bustedglass 1]

Hi TT, Yep, checked for dirt. Everything is fine in that department.

Ran it without an air filter, NO CHANGE..........

Checking the flywheel key ????????????? How do you do that ??

Thanks for responding...

[TT-(Moderator) 1,162]

Depending on the configuration of your engine, it might only require removing the debris screen on the top of the flywheel and the flywheel nut. If your engine is new enough to have the plastic cooling fins, you might need to remove the blower housing to remove the debris screen, the cooling fins, etc. to access the bolt that holds the flywheel to the crankshaft. (there are many different variations) You need to be able to look down in to the center hole of the flywheel and make sure the key has not partially sheared. This can actually happen on the newer Briggs engines just from the torque of the starter engaging.

You are absolutely sure that the choke butterfly is completely open?

[bustedglass 1]

Thanks TT for the response.

Yes, the butterfly is all the way open. Thank You for the flywheel help, I will get to that this weekend, and keep you informed.

[bustedglass 1]

Hi TT,

Yep, I have the plastic cooling fins. So I took all the stuff off that you told me to. The key is NOT sheared. Any other suggestions ???

[bustedglass 1]

Hi Guys,

Well I am going to bring this thread to a close . I want to say a BIG Thank You to all who resonded wiyh help to my engine problems. After doing all, and replacing all that I could think of, I got a carb rebuild kit over the weekend, and rebuilt the carb.

My little horse is purring like a kitten. The engine is running smooth as silk . I still wish that there was some adjustment on the government controled carburator , but I will live with it as long as it is running smooth.

Again, THANK YOU to everyone that helped me. You guys are the best :horseplay: :horseplay: .

[TT-(Moderator) 1,162]

That's great news, Mike!

Sorry I didn't get back to you with answers, but short of driving down there and getting my hands on it, I was out of ideas.

It still sounds like it may have picked up a little dirt, so you might want to consider a gas tank cleaning - and make sure you have a GOOD inline fuel filter installed.

:horseplay: "he's back in the saddle again......"

[T-Mo-(Moderator) 4,610]

That's great, Mike. Congratulations on getting her running again. B)

[bambooheels 0]

:horseplay: good for you, yeah it is very difficult to say when your not there working on it. sorry you had to go thru soooo much trouble, but atleast you hve her running. good luck with it.

[bustedglass 1]

Thanks guys. And hey TT - I did the gas tank cleaning, even if I did'nt want to. After putting everything back together, and test driving her, I put it back in the barn. I went in the barn Monday, and the gas smell about knocked me down .

The rubber grommet on the bottom of the tank had split, and gas was leaking out. I guess it had been leaking since I put it away on Saturday, because the amount of gas that had leaked down on top of the mower deck, had caused the paint to bubble up . Oh well, I guess a paint job is in order this fall .

Anyway, while I had the gas tank off, I gave it a good cleaning. The closest Toro dealer is about 25 miles away. I called before I went, he had the rubber grommet in stock. So I made the 50 mile drive for a $ 1.75 part . And alls well that ends well .

[combatmp29r 27]

MIke I'm glad to hear that after all the hard work you put into it you got her runnin again B)