Carb rebuild

[fiatster]

Wow, you guys are great! Lots of great info. The parts manual really will be a help. There really is a wide price range for the complete carb. Some of the prices seem pretty good considering the cost of the rebuild kit and solenoid. Here is what I ended up doing. I went to my local outdoor equiptment dealer and he order me a B&S rebuild kit ($46.50 + $10.00 shipping and handling). Great price on the kit, but the s&h is a little steep for a carb kit. I also was questioning if the solenoid might be part of the problem. The solenoid on this model seems to work in a way that it's extended, stopping the fuel flow until the ignition is turned on. It then retracts allowing fuel to enter. When I tested it on the 9 volt battery, nothing happened until I pushed the plunger in with my finger. It would stay in until I disconnected the battery. Seems like a faulty solenoid. Not totally convinced I had a great connection with the test wires, I reinstalled it in the connector on the tractor and turned the key. It snapped shut., but only 1 time. I kept trying, but nothing happened. Then I noticed that the tractor battery was almost dead. So I connected it to my truck battery and it worked every time. I guess it must be ok.

One thing that is a little confusing is reading on the internet that the sump being full of fuel (my problem and the reason for all this work) could be a bad solenoid. This seems odd because it's in the extended position when off (at least mine is) therefore not letting any or very little fuel into the carb. I must be missing something. In any case, I think I'll reinstall the same solenoid and move my shutoff closer to the carb. Worst case senerio would be the solinoid is indeed bad and I'll have to either relace it (expensive!) or clip it.

You guys have been great and I'll let you know the outcome when finished. Thanks.
Mike

 

[bertsmobile1]

The solenoids sit at the very bottom of the float bowl so the plunger is sitting in all of the crud that has accumulated in there.
Thus when it is energised the plunger drags all this crud deeper into the unit.
The plunger is just a lump of stainless, it can & does rust & corrode as well as get jambed by dirt.
it is non servicable so replace it.
Most solenoids have a trip limiting voltage and on the fuel solenoid it is around 10V..

As for information you see on the web,
Well there is no schoolmaster, correcting all the assignments so a lot of urban myths lurk on the web, along with a lot of misinformation posted usually by idiot ego maniacs .
We are all just electrons drifting about in cyberspace.
I could be an expert mechanic or I could be 12 year old who gets their jollies by deceiving people on the web.

You as a consummer have to do what we all do, look at what you see & read and evaluate the quality of the information.

As for the fuel solenoid, all it does is shut off the fuel supply to the main jet.
The main jet is not the only connection between the carb & the engine.
Thus if the FLOAT VALVE is not shutting off the fuel supply to the carb, the float bowl will fill to the top.
The fuel will then flow through the vent holes and into the engine.

If the float valve is working and stops the fuel entering the carb then obviously no fuel will flow into the stationary engine, solenoid valve working or not.

Now don't believe me, take the float valve out, assemble the carb, hook it up to a fuel supply that has a gravity head over the carb then see what happens.

 

[fiatster]

Greetings from the other side of the world. Thanks for the input. I am sure you are very correct in what you say about the perils of the internet. I too try to check out the sources as much as possible.

As for the solenoid position, on this carb. it's located thru the side of the bowl, but I suppose it still could gather gunk around it.

I did charge the tractor battery since my last post and reconnected the solenoid the proper way. Works great, so I think that's one part I can save buying.

Thanks again. BTW...You live in an area of the world that I would love to visit someday. Seems like a beautiful and interesting country.
Mike

The solenoids sit at the very bottom of the float bowl so the plunger is sitting in all of the crud that has accumulated in there.
Thus when it is energised the plunger drags all this crud deeper into the unit.
The plunger is just a lump of stainless, it can & does rust & corrode as well as get jambed by dirt.
it is non servicable so replace it.
Most solenoids have a trip limiting voltage and on the fuel solenoid it is around 10V..

As for information you see on the web,
Well there is no schoolmaster, correcting all the assignments so a lot of urban myths lurk on the web, along with a lot of misinformation posted usually by idiot ego maniacs .
We are all just electrons drifting about in cyberspace.
I could be an expert mechanic or I could be 12 year old who gets their jollies by deceiving people on the web.

You as a consummer have to do what we all do, look at what you see & read and evaluate the quality of the information.

As for the fuel solenoid, all it does is shut off the fuel supply to the main jet.
The main jet is not the only connection between the carb & the engine.
Thus if the FLOAT VALVE is not shutting off the fuel supply to the carb, the float bowl will fill to the top.
The fuel will then flow through the vent holes and into the engine.

If the float valve is working and stops the fuel entering the carb then obviously no fuel will flow into the stationary engine, solenoid valve working or not.

Now don't believe me, take the float valve out, assemble the carb, hook it up to a fuel supply that has a gravity head over the carb then see what happens.

 

[Boobala]

I forgot to mention, if you have a digital camera .... USE IT ! Take pics before & after as you work on things .... a few min. of pics could darn well save you hours of guess-work later. Glad you went the kit route , just take your time and double check everything ...be sure there are no fuel leaks .. the net has many pics of fire ravaged mowers ... Also there are some carb repair videos on you-tube ,
...........https://www.youtube.com/results?search_query=taryl+rebuilds+briggs+twin+carburetor

This guy Taryl seems to be an idiot but its all an act , he's really quite knowledgeable ..... Later ..... Boobala

 

[bertsmobile1]

I forgot to mention, if you have a digital camera .... USE IT ! Take pics before & after as you work on things .... a few min. of pics could darn well save you hours of guess-work later. Glad you went the kit route , just take your time and double check everything ...be sure there are no fuel leaks .. the net has many pics of fire ravaged mowers ... Also there are some carb repair videos on you-tube ,
...........https://www.youtube.com/results?search_query=taryl+rebuilds+briggs+twin+carburetor

This guy Taryl seems to be an idiot but its all an act , he's really quite knowledgeable ..... Later ..... Boobala

Standard teaching technique.
Load your lession with as much silly humour as you can and it becomes a great aid to retention of the useful information.
Other little trick is he has a channel & gets paid every time you visit for 15 sec or longer.
Loading the silly business makes you stay on channel so he makes a cent or two plus a couple more if you stay till the end.

This is why nearly all of the videos start with a bit of a leader then go on with a graphic introduction.
Time them and you will find most don't tell you anything till 15 sec are up.

 

[fiatster]

Well just got my rebuild kit and assembled the carb, but have one question. Even though I tried to take as many pictures as possible, I not sure about one thing involving the solonoid. the solonoid is the kind that mounts through the side of the bowl, not the bottom. In the rebuild kit it shows part 276A, sealing washer. in the kit I got there is a non-metal washer that seems like it might be the correct one.
So does anyone have experience with this? My thoughts are that since the solonoid plunger is fully extended to cut off the fuel when there is no power to it, if I add an unneeded washer, the plunger may not extend far enough to seal the fuel off. Thanks

 

[SeniorCitizen]

I can't help with your washer because I could never get my solenoid off to test it so I just went by the sound it makes and the feels like it's working method.

In my opinion there is probably a good range of plunger travel there but I don't see a need of deviating from original washer thickness.

 

[fiatster]

Yeah you're probably right. I must have lost the original washer because when I put everything on my work bench to do the job, there was no washer. In any case, I used the one in the picture and put the carb back together. The one in the picture looks like it's made of gasket material. If it's wrong, it won't be too hard to swap it over to the metal one. After I reinstalled the carb the engine started and ran. It was a little rough with some surging, but I think I may need to tweek it a bit. I put it up for the winter and will adjust everthing in the spring.
Thanks for the input.
Mike

I can't help with your washer because I could never get my solenoid off to test it so I just went by the sound it makes and the feels like it's working method.

In my opinion there is probably a good range of plunger travel there but I don't see a need of deviating from original washer thickness.

 

[Boobala]

Yeah you're probably right. I must have lost the original washer because when I put everything on my work bench to do the job, there was no washer. In any case, I used the one in the picture and put the carb back together. The one in the picture looks like it's made of gasket material. If it's wrong, it won't be too hard to swap it over to the metal one. After I reinstalled the carb the engine started and ran. It was a little rough with some surging, but I think I may need to tweek it a bit. I put it up for the winter and will adjust everthing in the spring.
Thanks for the input.
Mike

Be sure theres no fuel in the carb. before you store it ... or another cleaning in the spring will be greeting you !! Boobala :thumbsup:

 

[fiatster]

Be sure theres no fuel in the carb. before you store it ... or another cleaning in the spring will be greeting you !! Boobala :thumbsup:

Yep. I installed a new shutoff near the carb and ran her dry. Thanks. Haha..."Boobala" that's what my wife calls me when she's not mad at me.