Got an old Briggs 140200 with a stuck choke...

[01rangerxl]

One of my friends ended up with an old MTD tiller with a 5 horse Briggs & Stratton 140200 horizontal engine that has a Pulsa Jet carb. It looks to be 40-45 years old probably, but I have no idea since I haven't uncovered the serial number yet. I definitely think it is older than the circa 1975 Techumseh powered Sears tiller I "flipped" a couple years ago.

It was clear right away that it needed a new tank to carb gasket and a couple other gaskets/grommets. My friend was able to get it to run by spraying gas down the carb though, so it's definitely worth tinkering with. I have a new carb to tank gasket, diaphragm, intake gasket, valve cover gasket and grommets, fuel pickup tubes, and spark plug ready to install. I'm hoping those parts will be all it needs to be a strong runner, but first I need to finish cleaning it up.

The only thing I haven't been able to figure out with it so far is what is going on with the choke. It's not like any other choke setup I've seen. There's a round metal grip at the end of the carb that says "choke" on it and an arrow clearly pointing outward. I can't get it to budge though, either out or by twisting from side to side. It appears to maybe be a tube inside the barrel that slides to close the air filer end. I sprayed the carb down with Deep Creep last night and have let it sit, but the choke still won't move. There's not a lot of corrosion on it, but maybe enough to make a metal on metal tube stick. Unfortunately the parts diagram doesn't show the choke separate from the main body of the carb.

Has anybody ever freed up one of these things? Any tips to loosen it, or am I just trying to use the choke wrong? I figure if it's stuck for good, starting fluid will do the trick, but since I have the carb off the tank anyway it would be nice to get it working. I haven't tried Vice Grips or anything yet because I'm not sure how delicate it is.

 

[Donald]

Heat? PB Blaster? BFH?

 

[01rangerxl]

I'm thinking the amount of heat needed to free it might damage the carb in some other way. If I don't get it unstuck before reassembly, we'll see if it frees up when the engine gets up to operating temp.

I have PB Blaster and will try it, but if Deep Creep had no effect at all, the same will likely be true of PB.

As for BFH, this thing is four decades old...they don't make them anymore. If I could get a new replacement I'd try that.

 

[greenaccord02]

Shouldn't be terribly delicate. Most likely the little rivet that holds the inner, sliding part of the choke in place (bad description, I know) has become corroded... Can you post pics? I have a few older carbs that might be the same - we may be able to figure something out by comparing a similar, functional model. I'd think something like PB followed by some light, persistent taps with a hammer would get it moving again...

 

[01rangerxl]

Here's some pics of the carb...

The rivet actually looks really clean. I will let it sit with some PB Blaster and see if I can get it loose.

Here's the old beast the carb belongs to...

 

[Quest]

It's a plunger type choke. I have one of these similar carb on my B&S on MTD tiller also (late 80s/early 90s).

pulling it out to richen the mixture...pushing it in to defeat.

Q.

 

[greenaccord02]

I'd whack it lightly with a hammer and twist it a little back and forth with some vice grips. It'll come. Probably just has some grit between the two parts. They're pretty sturdy little guys, I wouldn't worry about busting it.

 

[TFB1]

It's likely early 60s... B&S didn't start the code system of dating till '65, you probably won't find one...

In pict next to last, would it be possible to insert a small screwdriver at the end of the choke slide and pry it open???

 

[01rangerxl]

It looks like the Deep Creep just needed some time to work. I gave the choke a pull yesterday and it started working perfectly.

I'm waiting on a couple more minor parts for the engine that should be here Monday or Tuesday. Hopefully it will be running next weekend.

 

[01rangerxl]

Well I got it running this weekend. I was going to wait on a couple more parts, but decided to start messing with it a little more today, and she's definitely a runner.

I didn't know the choke was "automatic." Pretty neat how it pops back in when the engine turns over. This old thing starts on the first or second pull too. The recoil rope broke the first time I gave it a good pull, but I took the rope off a junked Honda I have and it's back in business.

The threads in the block where the carb bolts go are partially stripped. A previous owner used the wrong size bolt in them and tore them up, which causes a bit of an intake leak (smoke around one of the bolts). I'm going to put a slightly larger bolt in and hopefully that will work. Other than that all it needs is a gas cap, reverse belt, and tine sharpening. It runs very strong, and the transmission is working in forward. Not bad for about $15.