so I was fixing an old lawnmower engine from the dump with my friend just for the heii of it. I think we got it down and we just need to test it. we’re going to anchor it down of course, but my question is, do I need resistance like the blade so the enging doesn’t go crazy, or can we just run it w/out the blade or resistance of any source?
Ductape can fix EVERYTHING!!!
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Replies
Put a blade on it.. it's part of the flywhell and will actually help the engine start.
Liberty = Freedom from unjust or undue governmental control.
American Heritage Dictionary
Put a blade on it.. it's part of the flywhell and will actually help the engine start.Assuming the motor is still in the housing<G> Winterlude, Winterlude, my little daisy,
Winterlude by the telephone wire,
Winterlude, it's makin' me lazy,
Come on, sit by the logs in the fire.
The moonlight reflects from the window
Where the snowflakes, they cover the sand.
Come out tonight, ev'rything will be tight,
Winterlude, this dude thinks you're grand.
yeah, the housing's gone. long gone
Ductape can fix EVERYTHING!!!
DO NOT put a blade on it.
The self contained flywheel is plenty for it to run.
Did you check for valve stem stretch? ; probably one of the main items after plain ol cylinder wear that makes people throw away small 4 cycle engines because of low compression..
And I suppose when it is valve stem stretch, you grind the stem down and then cut a new retainer groove ?;o)(Hey, I -=would=- if I had the means.) ;o)
When it rains, it snows.
iffen you need a new retainer groove, it's time for a new valve....."there's enough for everyone"
Killjoy.He could learn welding, first. Filling in the old retainer groove. Then he could learn the lathe, making a new one.;o)
When it rains, it snows.
God I see some 14 year old kid getting hurt here!
I used to work on lawnmowers for a friend who owned a rent shop. Back then all 2 stroke engines needed the blade to act as a flywheel but 4 stroke engines could be run without the blade.
roger
nope, just put shims under the valve springs and true the end of the valve stem. what you're concerned with here is seat pressure being compromised by the valve stretching. shimming the spring keeps the spring installed height and the the seat pressure as original. Jim
just grind a little off the valve end, no need for new groove
Luka,
Junkhound is right, just a little grinding is all you need to do if it's streched.*. , all I can add (which I'm sure junkhound would have mentioned) is when you remove some from the tip of the valve don't use a coarse stone. The deep gouges will quickly ruin the camshaft.. smooth it out to the point it's as smooth as a baby's bottom..
* a way to know if it's stretched is if the valve won't seat completely on the backside of the camshaft if the valve is fully seated then nothing has stretched.
You know that old saying about forgetting more than someone else has learned ?Well I don't think I am in danger of ever forgetting more than someone else has learned, but I do regularly forget what I have learned...I made a living as a mechanic for a while.I already knew about grinding the valve stem. I also knew about shims going under the spring, and a few other tricks to do with a cylinder head/valve job.But... I forgot all that. Probably would have come back to me if I were faced with actually rebuilding a cylinder head. But for question and answer time... Nada.;o)
When it rains, it snows.
I have absolutely no clue what a valve stem is and it's stetching is/looks like
Ductape can fix EVERYTHING!!!
Here ya go , doode, be all that you can be<G>http://www.youtube.com/watch?v=zT60SkXN1UY
Winterlude, Winterlude, my little daisy,
Winterlude by the telephone wire,
Winterlude, it's makin' me lazy,
Come on, sit by the logs in the fire.
The moonlight reflects from the window
Where the snowflakes, they cover the sand.
Come out tonight, ev'rything will be tight,
Winterlude, this dude thinks you're grand.
You ever see "The visible engine"?
I had one once. It's a plastic model of an engine, that runs if you put it together right.
Well it doesn't really run, it has battery that make it turn over.
Pretty cool tho came with the parts for a standard V8 or a turbo one.
i have gifted more than a dozen mowers to people that were curb finds...
many needed nothing... but i find the #1 reason mowers won't start ... that were running fine is... broken keys in the flywheel... hit a root or rock or curb... seems to be the cause...
around my parents house... seems older people just put em on the curb when they hire a lawn crew and no longer need a mower...
i got 3 in one day once...
p
Good job fixing dump treats - SeeYou especially loves to do that!
Forrest
You don't need any blade. Think about all those small engines that idle with nothing engaged (like a snow blower or a lawn tractor in neutral).
fixing an old lawnmower engine
absolutely no clue what a valve stem is
Uh, did that when I was a kid too, but....
Not trying to be facetious Andy, but did you actually take the engine apart or just look at the outside and twist a few carb screws?
You gotta tear it fully down to learn anything. IF you dont have a flywheel puller, a hammer is fine to use on an old junker. As a learning experience, you usually can get away with re-using the existing gaskets by piecing them together with rtv.
Like ponytl says, first thing to go on a lawnmower is usually the shaft key. 2nd thing is the points often get corroded from sitting open too long and no longer make electrical contact. Many times these need to be fixed often. The valve stretch is most often encountered as the first failure on engines used for items such as generators and pressure washers, where they run a long time with no shock loads (as in hitting a root or rock with a lawnmower) and dont sit idle for long either.
If you don't know what a valve stem is, you may not know what a flywheel or woodruff key is either? Time to google some.
ABSOLUTELY DO NOT PUT A BLADE ON IT!!!!
Gotta agree with junkhound. Take it apart, handle all the parts, see their relationship to each other etc.
Then when you look at a manual or read something it'll make a lot more sense.
You'll learn more from that then anything...buic
PS Even if it doesn't get put back together, what do you care if you got it for free! And, the next one will seem 10 times easier!
EDIT : No blade if you're "bench testing" that puppy.
Edited 2/26/2008 3:38 pm ET by BUIC