Used Mower Make/Model Suggestions for Son

[Rivets]

When I taught small engine repair, every student had to completely teardown, measure, and reassemble an engine in one semester. Along with classroom work there was no better way to learn how an engine works. Many of the engines did not run at the end of the semester, because the parents didn't want to stick any money into it. No problem, as the students understood how it was supposed to work. Also, helping other students troubleshoot their engines was a great team learning experience. I would start with a Briggs or Tecumseh, as their repair manuals are available in PDF form on the Internet for free. Once they understand how each part works together and alone, you will be a better troubleshooter down the road. This is one lesson that persons on this forum need to learn before attempting to work on their equipment and posting questions.

 

[reynoldston]

When I was young and on the farm I always had what we called lot cars that I ran around on the farm with. I was always pulling the engine's out of them and experimenting with them. Back then you could buy a old farm car for 20 dollars just to beat up, take apart and put back together. Take a 6 cylinder engine out and install a V8. Didn't know what I was doing but sure learned a lot. The repair business just stuck with me, even now into my retirement. I say if he wants to learn the repair trade just do the same thing only with mowers, he doesn't need to spend big money to get his hand dirty. With all the new technology I would recommend that he goes to a trade school before making a living at it.

 

[BlazNT]

Being a member to multiple forums has nothing to do with it at all. It's your forum so whatever floats your boat. I am not used to mediocre moderating.

I bet that would get you banned in the other forums you speak about. One of the reasons we like it here is because the moderator is not a total notzie about his site. I have never thought of this a mediocre moderating I have always though of it as a HELP site that allows you to help not worry about little stuff.

 

[primerbulb120]

I bet that would get you banned in the other forums you speak about. One of the reasons we like it here is because the moderator is not a total notzie about his site. I have never thought of this a mediocre moderating I have always though of it as a HELP site that allows you to help not worry about little stuff.

I completely agree!

 

[primerbulb120]

When I taught small engine repair, every student had to completely teardown, measure, and reassemble an engine in one semester. Along with classroom work there was no better way to learn how an engine works. Many of the engines did not run at the end of the semester, because the parents didn't want to stick any money into it. No problem, as the students understood how it was supposed to work. Also, helping other students troubleshoot their engines was a great team learning experience. I would start with a Briggs or Tecumseh, as their repair manuals are available in PDF form on the Internet for free. Once they understand how each part works together and alone, you will be a better troubleshooter down the road. This is one lesson that persons on this forum need to learn before attempting to work on their equipment and posting questions.

Good point. When I first began working on small engines, I just assumed that every broken engine needed a complete overhaul before it would run again. I messed up several engines before I got my first one running, but I knew how they worked when I was done!

My first repair attempt was on an old McCulloch MAC 3200 chainsaw engine. (Just the engine, not the whole saw.) First I completely took it apart. After looking over the parts, I put it back together with no gaskets (and I think it was also missing the piston ring), hooked the carburetor up backwards and tried to start it with an electric drill because it was missing its starter. Of course it would not start. :laughing:

 

[bertsmobile1]

We have all been there.
Rip it apart rather than do a proper diagnosis.
Don't do it any more.
a 1/2 hour spent working out exactly what is wrong is 10 hours of unbilable hours saved.

 

[roo_ster]

OK, I have read up through page 9 of the monster thread "My Lawn Mower Repair Thread (56k warning)" and already learned a whole lot.

QUESTION:
How do you determine if a motor has compression?

 

[bertsmobile1]

You use a compression tester and a leak down tester.
Because nearly all small engines use some sort of decompression you never get an accurate maximum compression reading.
However you need 70 psi minimum for an engine to start.

My standard test is to pop an inline spark tester on the engine and a shot of starter fluid.
If it goes band there is sufficient compression to start the engine.
If it don't go bang and there is a spark, I pull the rocker cover and then check the flywheel key.
Easy things first. When ou do a lot of engines you can hear low compression situations, mower spins over faster than it should.

The big problem is there are a lot of cheap crap compression testers that give inaccurate readings.
The you get to the actual adapter.
It has to occupy the same volume as the spark plug does as on really small engines the actual compressed volume can be as little as 4 turns of the spark plug so if the tester goes in 1 turn too many it will give high readings and if it scews in 1 turn too few it can be 20% too low.

FWIW I usually test every engine and record it in the job book .
I do this every time I service that mower and use the numbers to monitor the wear in the engine.