Problem with old tiller...

gardentalk · #1 09/17/05, 05:43 PM

Today my wife and I went 'yard sale' shopping. We never expected to find a tiller for sale, for $35. Because we don't have a truck, we paid the old man $60 for the tiller and to take it to our place. Darn, does that thing jerk the snot out of you when it's running. No complaints, though, I knew it was going to be rough. At least we have a tiller, albeit a sick one. The problem is this. I'm not a mechanic, have a ton to learn about how motors work. I think it is the "choke", that little flap that moves slightly near the fuel tank. Anyway, if you hold that choke open, the motor runs fast, as it should (otherwise, you can't even get it to till because of how slow it runs). If you don't, then the motor will just sputter to death until it quits. Okay, so the only way I knew to be able to till was to keep the "breather" off the motor. I'm tilling along, and all of a sudden I hear a popping sound and it just quits. I pulled, and pulled, and pulled on the string to get the motor to start. No go. After doing it for probably 15 minutes or more, it finally started, but this time I didn't want to run the tiller without the breather on. What I think happened is that dust got into the area where the fuel and the flap is. Am I correct on that? If so, how can I fix this tiller so the flap stays open, so that I can keep the breather on? The filter inside the breather is so old that when you touch it, it just crumbles. Otherwise, I'm thrilled to even have a tiller, and am just amazed how it so finally breaks up the dirt.

moopups · #2 09/17/05, 06:19 PM

The 'choke' is the 'butterfly' located nearest the opening where the air cleaner is mounted, it usually has an outside control arm. This is attached to a wire within a wrapped wire control or a spring loaded keeper. It needs to be full open for the unit to run right. Replace the failing air cleaner, thats the first thing to do. Check on the second butterfly, you can see it when the first one is open, that is what goes to the speed control device usually mounted on the handles, if it does not respond to moving the control device, replace that also.

gardentalk · #3 09/17/05, 06:33 PM

In my case, there is not a second butterfly. Just one. When it is open, all you see is the 'chamber' with two holes (and the hole that the screw that holds down the breather goes into. That rocker arm assembly you talk about is broken. There was a piece of wire that was broken, which meant that the butterfly moves about freely, I think the old man that sold me the tiller took the wire. I'm trying to find a free website where I can upload some pics of this tiller. I hope I don't get laughed at for eternity. It is an OOOLLLLDDDDD tiller.

moopups · #4 09/17/05, 06:49 PM

What brand, model, type of engine are you working with? What brand tiller? 2 stroke engine or 4 stroke? If its four stroke then there has to be a second butterfly or there is a missing part problem. A 2 stroke engine need a mix of gas and oil to run, they are very dissimiliar in their internal workings. Can you post a picture?

gardentalk · #5 09/17/05, 07:03 PM

Working on it right now. The URL is going to be gardentalk.bravehost.com ... hopefully I can figure out how to decrese the size of the images I took of the tiller, enough for me to upload the images.

mink · #6 09/17/05, 07:41 PM

maybe the throttle cable isnt there and he is moving it by hand ? the choke flap should stay open if the govenor is working.....mink

gardentalk · #7 09/17/05, 09:21 PM

Okay, here are three images of the tiller. It took me forever to get this working online.

rambler · #8 09/17/05, 10:46 PM

If you want this tiller to get any older: Don't run it in the dirt with the air cleaner off. DO get a new element for the air cleaner. Can be had cheap at most any auto supply or farm supply or lawn center store. Any dirt at all will totally wreck your piston, and a tiller makes a lot of dirt. You probably did a lot of damage already, but - don't do that again! Really, really bad for the engine. This is terribly important, if it isn't too late already.

I'm no good at describing this and others will do much better, but you only need a little bit of linkage or bit parts to fix this. A tune-up kit or a lawn service center should get you everything you need for a couple bucks, if you can't find the parts on another junked out engine laying around on just about every corner.

If you have a throttle on the tiller, you would have a second butterfly. however, some are built to run wide open all the time, & don't have a real throttle - then you would only have the choke butterfly valve you see.

--->Paul

gardentalk · #9 09/17/05, 11:56 PM

If dirt were to get into the pistons, is it pretty easy to clean them? I'll see if I can find an element tomorrow for the breather, and see if I can pick up the linkage parts I need. Thanks for the advice.

rambler · #10 09/18/05, 10:48 AM

The dirt gets in between the valves & the pistons & their walls & totally eats up the metal. There is no 'cleaning' - it just destroys the engine as it rotates at several 100 or 1000 rpms. Oil will leak through the scores (tiny grooves) on the cylinder wall, and the engine smokes more - power leaks through thr grooves, and your engine has less power.

Keep dirt out.

--->Paul

moopups · #11 09/18/05, 11:55 AM

That is a 3 1/2 to 5 horse Briggs and Stratton verticle shaft 4 stroke engine. The yellowing plastic piece you see in the air cleaner hole is the main jet butterfly, the choke on these types of engines are the slide type, you can see the pull handle under the horizonal rocking linkage and speed control arm. It pulls out about 1/2 of an inch to activate the choke. Some of these engines are govornor control designed, meaning no throttle control on the handle bars. They are tricky to adjust, get someone older and exsperienced to check it out for you.

Under the moving speed control arm is a 4 screwed small plate, about as big as a old style cigarette lighter, under it there is a two tab flapper valve fuel control - these go bad with age but should still be available.

One other question, is there a slot at the rear of the unit, about 3/8th wide and 2 inches long? If yes, then there is the drag tail missing, its meant to slow the tiller like an anchor - should make it pull more smoothly.

Manny · #12 09/18/05, 12:02 PM

That little flap near the carb is not a choke control it is the throttle. It only affects the choke when it is pushed fully to the left. Speed is controlled by moving that flap to the right. That little hole in the flap is where the throttle cable would attach and go to the speed control lever on the upper assembly of the tiller. The problem with the coughing, dying and hard starting seems to be a lack of fuel. In this Briggs and Stratton engine the fuel is pumped from the main fuel tank into a small cup and from there to the metering jet in the carb. The fuel is pumped into the cup by a vacuum operated fuel pump that is located between the carb and the fuel tank. It is comprised of a gasket with some little valve flaps and a spring that uses the vacuum of the intake stroke to suck gas from the main tank. There are also filter screens on some pickup tubes in the tank that can become clogged and prevent fuel from being pumped. I would recommend that you remove the carb from the tank and take all the small parts, the gasket, spring and pickup tubes, to a shop that sells parts or repairs small engines and buy new parts (probably less then 10 bucks). Go to the library and see if they have a book on small engine repair or better yet a Briggs and Stratton repair manual to see how all these parts go together. The tiller looks to be an old Sears "Roto-Hoe" and the Briggs engine is something like a #92000 or #102000 series engine.

HermitJohn · #13 09/18/05, 06:11 PM

Had to get my reading glasses. This is vertical shaft B/S 3 or 3 1/2 hp lawnmower engine. Hopefully since it is on tiller, still has original engine with cast iron flywheel. On mowers they use aluminum flywheel and blade itself acts to smooth things out. If somebody just stuck lawnmower version of this engine on then its not going to run very smoothly and be jerky to start when you pull the rope.

This carb has the plastic butterfly choke that you see. It is a diaphram type carb and doesnt have float or fuel bowl. If you remove the carb/gastank from the engine and look into the opening that goes into engine you will see the throttle butterfly valve. Cant see it from looking down into carb. This is a variable choke and only fully shut when throttle lever is in choke position, though it will automatically close if engine starves for fuel. Otherwise choke butterfly can vary position on its own. Opening depends on engine vacuum. Remember this is a governed engine. you dont want to directly connect a throttle cable to the throttle valve. You just move the little lever you see and it adjusts linkage to governor. Governor opens and closes throttle valve to keep engine at constant rpm.

Carb kit for one of these is $3 or $4 at farm store, lowes, or maybe still at Walmart and pretty simple, do have to remove carb from gastank. There are basically two different carb kits you'll see in store like this. Look at shape of base of carb and count number of screws holing carb to gastank. Look for same when you buy rebuild kit. These carbs have two little stand pipes going down into the fuel tank. Both have fine mesh on ends to avoid sucking junk up into carb, but can get clogged themselves. People never seem to bother draining gas in fall nor adding fuel stabilizer. So things get gummed up. Some even just leave them exposed to weather and water gets in gastank. Really a mess when things rust then. On these engines if diaphram is weak but functional, you can get these started by holding choke open by sticking screwdriver or bolt down into carb throat (one big enough it wont fall in), then pour tiny bit of gas in (or one short squirt starting fluid) and crank. When it starts you can remove the screwdriver.

I suspect you need carb kit with new diaphram for this carb

Also put in new spark plug and redo points/condenser if it has such. Point gap is important on these engines as is sparkplug gap. If it has electronic ignition module and you are getting spark (guess so if you had it running) then you dont have points/condenser and if there is spark, ignition module is working. No adjustment necessary or possible with module, well except plug gap.

Dont forget to actually regularly change oil, not just top it off. These engines can last an amazingly long time (like 12 years) if given maintenence though they are commonly just considered throw away and people dont expect more than couple years out of them. I used to make some side money picking up old lawn mowers/tillers and cleaning points, sharpening blades, new carb kit so they started easy, then resell them. Then with electronic modules when they quit they usually had more wear and electronic module cost like $15 so not much profit left if I had to replace that. Also more competition for old non running mowers so gave it up. You by way can buy a brand new mower at Walmart with this exact same engine (has aluminum flywheel and may have different length shaft) tody for like $100. No choke on it, have to push the little rubber squeegy thing to prime carb, then they bent the throttle lever down so it runs at constant speed. Just bend it back up and you can adjust throttle again.. They do it because of EPA. Less emissions at high constant rpm. Cheap new mower really hurts market for used mowers.