Centrifical Clutch problem

[maradcliff]

I'm not even sure how to ask this, but I'll try. I have one of these earth augers (power post hole diggers). It has a 2 cycle 3HP engine, under the engine is a Centrifical Clutch, and under that is some gears (transmission), and the auger (drill) goes below that.

The problem is the clutch is not disengaging. When I pull the starter rope the drill already turns, and when it does start, I'm already digging which makes it impossible to have enough hands to set the choke lever and control the thing. Because of this, it got away from me, but finally killed after bouncing around on the ground for a minute.

I took this cent... clutch apart. It works sort of like the rear brakes (drum brakes) in a car. The engine connects to a round piece of steel, there are two dogs that fit around it with pivot points, and a spring on each end to keep the two halves together. I understand the principle. When the engine turns fast, the springs stretch and the dogs contact the "drum" surrounding it. Pretty much the same as the way drum brakes contact the drum, except this is centrifical.

On disassembly, I found the assembly attaches to the engine shaft with a set screw, and there is a key to lock it to the shaft. Everything was in working order, no rust, good springs, everything clean. However, the set screw had fallen out, so the whole thing was floating in there. I got a new set screw, and tightened it well. I pushed the assembly tight against the washer spacers on the engine shaft. I noticed the indent from the original set screw was in that same exact spot, so I know that's correct.

I put the whole thing back together only to find that it still will not disengage. As I said, everything appears in perfect working order on that clutch. This leaves me puzzled. I just dont know what else to do with it.

Has anyone worked on these sort of things? What can I do with it?

One other thing. I am wondering if the whole clutch could be upside down. I bought this auger at an auction, and the last owner could have tampered with it. When I removed the clutch assembly, I noticed that the upper part which contacts the spacers under the engine was very smooth, whereas the bottom side showed some wear marks from being loose (with that set screw out). I reassembled it the same way. This entire clutch assembly could be flipped over and installed upside down. It will fit either way. How can I tell which way is right? This is where I dont know how to word this question.... (here goes my best try). In relation to the rotation of the motor, how can I tell which is the correct way to install it to make the dogs fly outward when the engine speeds up? I can easily tell the rotation direction by pulling the rope a little, but after that, I'm lost......

Finally, if the clutch assembly were backwards, I would suspect it would not engage at all, rather than engage all the time. Is this correct thinking?????

(Unfortunately this thing has no brand name, no model number, so I cant even get a diagram for it).

Sure could use some help.....

Mark

[Robert Allison]

Centrifugal clutches wear out. It is probably done for. Take it to a small engine repair place or a chain saw place. They will be able to sell you a new one, usually off the shelf. If not, they will be able to measure it and order one for you.

[maradcliff]

OK, I can see where they wear out. But when they wear out, wont they NOT turn the shaft? Mine does not disengage. I just spent the last 3 hours taking it apart twice again (the 4th and

5th time). I carefully made sure the clutch parts are all free and working. The springs are right, everything moves freely, and there is 1/8 inch of clearance between the clutch and drum. There is no way this clutch should be engaging when the engine is at idle. Yet it does. I did notice that it was not going all the way back in (to it's seated or disabled mode). Only about 1/32 of an inch. I figured out that it was hitting the new set screw I just put in there, and that screw is just a tad longer than the original. I solved that by taking off about 1/32 of metal from the rear part of the dog that touched the screw (used a dreml tool with tiny grinder). It now seats properly. It still does not disengage. I then took it apart again, and flipped the whole clutch assembly over. Still got the same problem.

A small engine shop probably wont touch it. There is no brand name or model number. Just a un-named machine with a Tecumseh engine.

I just tossed it in my scrap metal pile. The amount of time I spent on it, I could have dug all 12 of my 3 foot deep holes with a hand post hole digger. Actually, had I known that engine was a 2 cycle, I would have never bid on the thing at the auction. I have always hated everything that has a 2 cycle engine. I can cut a tree faster with a hand saw than I have ever done fighting with chainsaws. In fact the last tree I tried to cut with a chainsaw, I had to cut by hand. I was so pissed at that chainsaw I placed it under the tree, hoping the tree trunk would crush it. The tree missed. Just my luck.

I am going to save the auger bit from this thing though. I already figured how I can mount the auger to a pulley, put the pulley on a steel plate with an electric motor, belt and pulley and have a belt idler for the clutch. Electric tools are always better than gas, unless there's no power nearby. In my case there almost always is, if not, it's back to hand tools.

Mark

[John Lawrence]

I suspect that the springs have lost their original tension and that low RPMs, such as idle speed, is suficiant to allow the weights to be applied. Think about it. If the springs were say too heavy, the clutch would not, could not, engauge. The reverse would be true if the springs were too light or have lost their tension.

[Larry Caldwell]

Centrifugal clutches are a stock item. So are the parts.

AHAH! You bought someone else's junk. Chances are they tried to fix it and screwed it up. Most likely they installed springs that are too weak.

Too bad about you and 2-cycle engines. I find they are very reliable as long as I never leave stale fuel in the tank or carb. Always run them dry before putting them away. I have 2-cycle engines that have been running reliably for decades, some so old they need a 16:1 mix.

[Frank K.]

It's possible that the engine is not idling slow enough to allow it to disengage. Adjust the idle and see what happens.

Frank

[Eric in North TX]

I'll give your origonal $5 for it.

[maradcliff]

Yeah, I do think someone else f**ked something up on this thing, but I can not see any possible reason what..... This is one of those repairs that make a person rip their hair out. It's not that the engine is idling too fast as someone suggested, because it starts to turn the drill when I pull the rope. The springs "could" be weak, but there is no way they are that loose that they are going to release when I just pull the rope. Actually, those springs seem very strong to me. In other words, it seems that they seem like it would take considerable force to expand them.

The dogs (or shoes as I noticed them called on some websites). measure

2 7/8 inches diameter when attached as they should be. The drum they sit inside of is 3 inches. That means there should be 1/8" of play. The drum / shoes can not be off centered when the two halves are bolted together because the bolts only go in on way and there is no play from side to side.

I measured the depth, the diameter, everything else imaginable, and there just is no explanation for this. I have just run out of ideas, and do not know what to do any longer. Now that I am not totally stressed out over it, I am going to take it over by a neighbor who seems to be able to fix any large farm machinery. If he can fix those big combines and stuff, maybe he can make sense of this. I surely can't. As they say, two heads are better than one.

The bottom line is this. When a 2 7/8" circle is placed inside of a

3" circle, there should not be any side contact. Yet, there is.... I guess????????? Like I said, I've just run out of ideas..... Using it the way it is now, is pretty dangerous too. I found that out twice now when it got away from me. I also found that when it does start to dig, the engine kills when it really starts to dig in. I know the clutch is supposed to slip on heavy load, but it obviously don't.

As for other 2 cycle engines, I have never had luck with them. Seems everytime I need a chainsaw or weed whacker, it wont start. When I heated with firewood, I spent more on chainsaw repairs than it cost me to buy propane fuel for the furnace. That dont include the frustration either. I'd get them fixed, they would work, then I dump the gas when finished, add stabalizer, and a few weeks later I spend hours pulling the rope and getting pissed. At least the engine on this auger is running. I'll give it that much..... I just wish all engines were 4 cycle..... Must be some reason they dont use 2 cycle engines on cars.....

Thanks for everyone's help.

Mark

[Don Young]

If the clutch is not transmitting power by the normal surfaces, then there has to be insufficient clearance lengthwise between the shafts or there is a misalignment. Something rotating has to be touching something which is supposed to be stationary. Can you check carefully as you put it together to figure out where the contact is?

These diggers are not nearly as easy to use as one might think. Even the two man type will give the users quite a workout unless the soil is very soft. The reaction has to equal the digging force so if you can imagine how hard it is to screw the auger into the ground, that is how hard you will have to hold back on it. The only practical type of digger is mounted on a tractor or other machine, in my opinion. Don Young

[Big Al]

When it's together can you turn it with your hands?

Al

[digitalmaster]

The carb is what gets messed up.

[Bob]

I usually run the engine dry, turning on the choke as it starts to falter to burn the last fuel it can get.

Bob