Small engine repair ?

[glockrod]

Alright, I know someone on here know small engines and I figure that I may get my fastedt reply on GT.

I recently "inhereted" an old Murray 22" highwheel mower with a 5.75 hp B&S motor. I dont know much about this machine.

It has run fine for the little while I have used it.

I was mowing a thick area and choked it out. Before trying to start back up, I too a little break and cleaned up the area a bit.
When I went back to crank it, I pulled the cord and nothing. The cord did not even rewind, which I thought was odd as it had not ever done that before(the 15-20 times I cranked it before anyway).
I thought how in the world was I going to get the cord back in when it hit me to turn the blade to make the cord rewind.
Well, it worked, and cranked up, but ran awfully bad. So, I cut it off to check to see what was happening. Nothing stood out so I tried cranking again to see if anything changed.
Well, now when I pull the cord, it just pulls and rewinds. It's like it doesnt even engage to motor to turn it over.

I am at a loss. What have I done? And mostly, have I FUBAR'd the mower?

[paynter2]

Take the rewind off (three screws) and make sure the spring isn't broken. It probably isn't. But a new sprint will help.

Fresh gas and a new spark plug. If that doesn't work, take it in for a 'tune up'. Your SE mechanic will probably 'sand' the magneto for better contact. If it ran before, it will run again - it isn't 'blown up'.

If you're really interested in this - get a small engine repair book. Or better yet, take a course at your local tech school. SE's are fun to work on. And you get free mowers! :wavey:

[F14Scott]

Without offering any further comment, I have one important one:

If you are not disconnecting the spark plug while you are hand-cranking the blade, DISCONNECT THE SPARK PLUG!

Otherwise, you may compression start the mower with your hand in the rotor system. Picture a biplane: CONTACT!

[glockrod]

I had already thought of that possiblity and took the proper safety precaution.
I figured that it would be MUCH easier to finish my work if I still had my arm below the elbow.

I am going to throw something out:
I dont remember which direction I spun the blade right now. Like an idiot, if I spun the blade the wrong way and wound the cord backwards, would that cause the problem I described. Basically, I may have run the motor backwards(I have heard of this with diesels), and then the spool os backwards and wont actually turn anything now. When I pull the cord, I do get a ratcheting sound but definitely no turning of the motor.

I apologize for my horrendous spelling. I just cant seem to help it tonite.

[glockrod]

This is the oddest B&S engine I have ever seen. It does not have the starter cord housing bloted with 3 screws. I took the top cover off and couldnt instantly figure out how to do it. The recoil system appeared to be riveted on.

[paynter2]

This is the oddest B&S engine I have ever seen. It does not have the starter cord housing bloted with 3 screws. I took the top cover off and couldnt instantly figure out how to do it. The recoil system appeared to be riveted on.

I'm not your best SE source. My stuff runs good because it is good. I recently refurbished a rider for a niece - I can usually get mowers to run.

I'm not sure what you have there - if the recoil will not come off. Probably a cheap Home Dumpster model. But it should still run. I doubt you could turn it the wrong way.

Try to get that rope into the rewind. It (rewind) has to come off somehow. Maybe, if you can get the rewind off, you can just use a rope with a knot in it to turn the motor over.

Put fresh gas and a new plug into it. Give a squirt of WD-40 into the plug hole before replacing the plug. Then pull the rope. Generally, unless there's a real problem it will fire and run.

Play with it a learn to fix them - it's fun to work on them. Replacing a magneto isn't difficult. The mower for the niece (above) needed a mag. I went to our local landfill and got one off of a junk mower.

[VC-Racing]

The starter mech will only grab in 1 direction. It is designed to slip when rotating . In would spray some lube on the starter mech . It probably has some rust prohibiting it from catching a cog to crank the motor. I also agree some fresh gas and a dose of SeaFoam should smooth out a rough running engine.

[glockrod]

The mower was running fine, excellent even, before I maged to choke it down.

It is running on fresh gas, new plug, and freshly cleaned carb. Again, it was running really good. It didnt start running bad until after I would the cord back in by turing the blades.

paynter, the cord is retracting. It is not pulling out and staying out. It just did that the one time and was the reason I turned the blade to retract the cord.

VC, that is kinda what I think I may be getting at. The cord only pulls(rotates the motor crank) the one way. Is it possible the cord is wound back on the spool the wrong way and could the motor have run in reverse?

[RenoF250]

You did not hurt it by turning it backwards.

Try tapping on the recoil starter and pulling the cord out with short fast jerks. That will usually break it loose if it is stuck and get it to work again.

[VC-Racing]

You did not hurt it by turning it backwards.

Try tapping on the recoil starter and pulling the cord out with short fast jerks. That will usually break it loose if it is stuck and get it to work again.

+1

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[racer11]

I had already thought of that possiblity and took the proper safety precaution.
I figured that it would be MUCH easier to finish my work if I still had my arm below the elbow.

I am going to throw something out:
I dont remember which direction I spun the blade right now. Like an idiot, if I spun the blade the wrong way and wound the cord backwards, would that cause the problem I described. Basically, I may have run the motor backwards(I have heard of this with diesels), and then the spool os backwards and wont actually turn anything now. When I pull the cord, I do get a ratcheting sound but definitely no turning of the motor.

I apologize for my horrendous spelling. I just cant seem to help it tonite.

Now you pull the starting rope and nothing happends,,,, and the motor ran crappy after you choked it down and it died,,,,, You may have sheared off the key on the flywheel and now the flywheel is just spinning around. With the key partially sheered off that would change the ignition timing and result it running bad,,,,when you tried to start it you finished shearing off the key.

[glockrod]

I really hope racer is not right!

The pull cord is not making any effort to touch the motor. It's like it is just spinning free on its own. Whe you turn the blade, the top of the engine also moves.

I really need to brush up on my technical terms for SE motor parts, but my description are the best I can do without misnaming a part.

[VC-Racing]

If it is sheared, its about a simple 30 min repair with the correct tools.

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[aircarver]

Nobody's mentioned it yet, make sure the air filter's not clogged up as to the running problem.

The pull start has either broken the rachet engagement mechanism or it is clogged with grass/dust inhibiting it from working properly.

.

[jlprtr]

I really hope racer is not right!

The pull cord is not making any effort to touch the motor. It's like it is just spinning free on its own. Whe you turn the blade, the top of the engine also moves.

I really need to brush up on my technical terms for SE motor parts, but my description are the best I can do without misnaming a part.

I'm pretty certain that racer11 is correct. Had it happen to me once or twice on B&S engines. Easy fix once you get the cover off. The key can be found in most any hardware store.

While you have it apart make the checks suggested by VC-racer and aircarver, then you should be good to go.

You can probably get all the info you need here:

http://www.briggsandstratton.com/

[SC Tiger]

This is the oddest B&S engine I have ever seen. It does not have the starter cord housing bloted with 3 screws. I took the top cover off and couldnt instantly figure out how to do it. The recoil system appeared to be riveted on.

I can't see the pictures if they are there but some engines now have the recoiler made into the engine shroud. Look for bolts going into the side of the block instead of right around the recoiler.

If you get the recoiler off, flip it over and look at the underside. When you pull the rope two fingers should extend and catch a stamped part on top of the flywheel. If they are not extending, they will not engage the flywheel to start the motor.

[fgutie35]

the B&S engines have the "flywheel" shaped like a bowl. on the side there are gills. those gills are meant to be engaged by the theeth or claws in the starting mechanism. Remove cover with starting mechanism. Inspect claws, make sure they are not broken. If they are not, they might have become disaligned. put back cover, making sure the bolts align correctly with no force needed. This insures proper aligning of claws with gills on flywheel. To check if engine still running, use a 1/2 impact socket and air rachet. to turn the blades in the right direction to start engine. Remove blade first for safety!!:wavey:

[byf43]

From the sounds of it, you've sheared the key off.

The key is inserted into the top (side) of the crankshaft, and keeps the flywheel in the correct 'timing' for the electric spark generated by the magneto (aka/ 'Magnetron').

The recoil starter used to be connected to the flywheel, and you turned the flywheel and that in turn, turned the crankshaft. (Here's another place that the key was important.)

The key is cheap enough. Usually less than $3.00.

Also, I don't advise spraying WD-40 into the cylinder, as a starting fluid.
WD-40 used to be propelled by propane. Not now, from what I understand.

I do recommend using plain, old lighter fluid as a starting fluid.

[MrKandiyohi]

If you're working on the spring, wear safety glasses. It's under quite a bit of tension.

[southernshooter]

If, instead of just choking it down, you hit a hard object and then it choked down then it probably is a sheared pin. If it will crank at all with a sheared pin it would probably be backfiring and popping. I think there are youtube videos of how to change the shear pin on a B&S mower.

[glockrod]

My neighbor used to be in SE repair, and he was gracious enough to look at it for me.
Apparently, I just didnt dig hard enough to figure out how to get the cover off.
When we(I say we loosely and mean he) peeled the gas tank back and got the cover off, he thinks he found the problem.
On top of the flywheel, held down by the big nut, there is a little bowl shaped device that the recoil starter fits down in to. Well, it is supposed to be attached anyway. Apparently, after years of sitting outside, the bowl rusted and finally corroded to the point that it detached.
Per my neighbor, that is why the recoil starter cord just pulls and retracts with no resistance and what the weird noise I heard the last time it did run actually was. The bowl was just loosely rattling around on the flywheel.

Now, if we can just get the rusty old bolt off, I can replace the bowl and be back in bidness.

I have hit it with penetrating oil and my air compressor impact driver at full 120 psi pressure, and it will not budge!!
I will let it soak in oil over nite and try again tomorow.
My neighbor says that he has run into some very stubborn nuts before.

I asked him if that was really a commment about me!:rofl:

He didnt answer!!:whistling:

He really is a great neighbor and I help him out cutting firewood about every year.

I'll update again when it is running.

[glockrod]

And I actually did all the repair work myself(although my SE repairman neighbor's advice is what got me thru it).

Ended up that the rusted bowl was the entire problem and now it runs great again.

Thanks for all the help and advice everyone. Looks like my problem may be something else to look for if your mower stops running. The SE repair/parts place that had the part said that he only has seen that problem a couple times in his over 20 years in the business.