Where is the Random Thread of Randomness stuff that doesn't belong in other threads thread?

[Loktar]

Firemen and a baby was right there.

 

[Colonel Kira's Left Tit]

 

[Dr Dave]

 

[Volpone]

Does anyone here understand lawnmower engines? I probably understand them more than most people, but there's a lot that baffles me. Mowing a lawn today. Blade lightly grazed a paving stone at the very end. Had a look under and the blade wasn't perfectly lined up on its mount (there are 2 holes in the blade and 2 pins in the mount so it's all supposed to lock together). But it looked like it was close enough, I didn't have my tools handy, and I was trying to get a job done. Mowed for a bit more and suddenly the engine starts idling terribly--way low rpms and Brrrmm!....brrrrmmm!....brrrmmm!....brrrmmmm!.... while black puffs of smoke come out the exhaust in time with the revs--instead of the regular BRRRRRRRRRRRRRRRRRRRRRRRRRR........ Tried killing it and restarting. Tried adding gas. Tried pulling the air filter. Tried pulling the muffler. Fiddled with the throttle linkage. No luck. Limped along for awhile but the engine died again so I had another look underneath. The blade was significantly misaligned. Since the weight of the blade and the effect of grass hitting it is a pretty big part of lawnmower load I scrounged some tools and put the blade back where it was supposed to be. No significant improvement--although there was a slight improvement and the engine sounded like it was trying to get back into its proper groove. Finally I had a big nasty clump of grass so I tilted up the front of the mower and lowered it down onto it--and the engine roared back to normal.

So clearly the blade misaligning caused the problem but in addition to realigning the blade, apparently the engine needed a sort of load shock to jar it back to normal operation. Weirdness.

 

[Loktar]

In my day, we had a push lawn mower, we didn't need no high falutin' fancy gas powered mower. *breaks a hip*

Get off my lawn, ya whippersnappers!

ZZZZZZZ.....Nap time....

 

[Dr Dave]

 

[Volpone]

In my day, we had a push lawn mower, we didn't need no high falutin' fancy gas powered mower. *breaks a hip*

Get off my lawn, ya whippersnappers!

ZZZZZZZ.....Nap time....

I had a push (reel) mower in college. My parents still had it and we never had particularly large yards--and it was a kind of hipster goofball thing to have, so that's what I used. I still use a push mower but it's the kind with a motor to power the cutting blade. Given that I have an acre of grass to maintain, I really should have a rider (or at least a push mower with powered drive wheels--I guess the term for that is "walk-behind").

 

[Dr Dave]

 

[Volpone]

Water is trippy. The house I'm getting ready to list is close to a flood plain and has a high water table. As it happens, the lowest spot in the crawlspace is right where the crawlspace access is, so when I bought it there were several inches of standing water preventing me from exploring the crawlspace. I bought a pump to get things dried out. Once I got under there to install a vapor barrier, I discovered a (dead) electrical outlet and a hole for a sump pump. So I got the outlet "hot" again and did the steps to convert my little pump to a sump pump. Of course when I took possession of it this week the sump pump had failed and there was several inches of water keeping me from getting into the crawlspace (along with a potentially live electric wire--and the pump I used to pump it out the last time). Luckily I happened to have 20' of 3/8" ID plastic tubing from another project and there was a (dried up) koi pond about 8' from the crawlspace opening. So I stuck one end of the tube in the water, with a rock on it to hold it in place, got down into the pond and sucked on the tubing. The tubing was clear so I could see when I could stop sucking and the fact that water is trippy did the rest. Because of the way water works, it will climb up a 20" vertical rise as long as the other end is lower than the end starting end.

I do kind of wish I'd done some work on the pond before starting the siphon. If I decide to keep it, it would've been so much easier to get it ready when it was relatively dry, but there's supposed to be rain coming and it would be nice to get into the crawlspace and see if I can get the pump running again before that happens. Besides, from the way the pond managed to hold siphoned water, it probably would've been wet when the rains come anyway.

And don't get me started on electricity. That's a whole other level of trippiness.

 

[Colonel Kira's Left Tit]

Does anyone here understand lawnmower engines? I probably understand them more than most people, but there's a lot that baffles me. Mowing a lawn today. Blade lightly grazed a paving stone at the very end. Had a look under and the blade wasn't perfectly lined up on its mount (there are 2 holes in the blade and 2 pins in the mount so it's all supposed to lock together). But it looked like it was close enough, I didn't have my tools handy, and I was trying to get a job done. Mowed for a bit more and suddenly the engine starts idling terribly--way low rpms and Brrrmm!....brrrrmmm!....brrrmmm!....brrrmmmm!.... while black puffs of smoke come out the exhaust in time with the revs--instead of the regular BRRRRRRRRRRRRRRRRRRRRRRRRRR........ Tried killing it and restarting. Tried adding gas. Tried pulling the air filter. Tried pulling the muffler. Fiddled with the throttle linkage. No luck. Limped along for awhile but the engine died again so I had another look underneath. The blade was significantly misaligned. Since the weight of the blade and the effect of grass hitting it is a pretty big part of lawnmower load I scrounged some tools and put the blade back where it was supposed to be. No significant improvement--although there was a slight improvement and the engine sounded like it was trying to get back into its proper groove. Finally I had a big nasty clump of grass so I tilted up the front of the mower and lowered it down onto it--and the engine roared back to normal.

So clearly the blade misaligning caused the problem but in addition to realigning the blade, apparently the engine needed a sort of load shock to jar it back to normal operation. Weirdness.

If the blade is cocked like that it will throw off the balance of the whole thing. On some engines at least they want the blade to be aligned parallel to the top dead center point of the piston, others want it 90° off, or perpendicular to TDC. Others don't care at all, depends on the brand. Or that's my experience, anyway.

 

[Volpone]

Now I gotta logic through that. OK, first off, I misread and that was the simplest answer. Like I said, there are these little holes and nubs that interlock when the nut is tightened down to hold the blade in place. If the nut is loose enough that the nubs get knocked out of their recessess, then the blade won't be perfectly flat/level and this could create an uneven power load on the motor.

But if it is related to the piston location then... The blade spins as you push the mower toward grass. Only the leading edge of the blade--on one side--has load. It hits the grass and cuts it while the trailing edge is dumping the grass it just cut and spinning around to cut the next swath. So, yes, it is logical that you would want the combustion to happen as the blade hits the next swath of grass...I guess. But it's still funny, because as soon as one side of the blade finishes cutting, the other side of the blade starts its cut. I guess the combustion uses all its energy/inertia turning the blade through the cut and reloading the cylinder so that as the cutting side is through the grass the combustion energy has been expended, the shaft has turned and the cylinder is compressed with a new load of gasoline and air, ready for a spark just as the other side of the blade hits the grass. I'll buy it.

Next two mysteries are why relaligning the blade didn't fix the engine problem but...ahh.... By lowering the blade onto a clump of heavy grass the entire blade is under load at the same time--instead of just one side. Maybe there was unburned fuel in the cylinder after the misalignment (or something) that was causing it to run poorly and that brief spot of even power helped to kind of recalibrate things. Someone who actually knows about these things would probably shake his head at this explanation, but I think it serves for now. And it gives me an idea how to reset the carb if/when it runs badly--lower the blade into grass instead of pushing it towards grass.

 

[Volpone]

Did they used to have whores on CraigsList or am I misremembering?

 

[Colonel Kira's Left Tit]

Did they used to have whores on CraigsList or am I misremembering?

They did until there was a crackdown on Craigslist Personals.

 

[Volpone]

I just committed one of the most basic blunders of troubleshooting: The first, of course, is "never get involved in a land war in Asia," but only slightly less important is "correlation is not causation."

Fired up the mower today. Idle problem was back. My literal "hack" to fix it wasn't working. In frustration I tried just tilting the front wheels up as high as I could--handle all the way to the grass, doing a "wheelie." Idle returned to normal. Periodically went back to the weak, cyclic idle and was always fixed by holding a wheelie.

Upon consideration, I had this problem with this motor when I decided to retire the previous mower. At the time I suspected it was a fuel or carburetor issue but hadn't been able to find and fix it. Theorizing that there is a fuel line obstruction of some sort. Letting it sit for years allowed it to dry out (and shrink) and/or stick to the wall of the fuel system. Returning the motor to regular use brought back the problem. One day I should maybe take it to a shop, but for now, as long as I can keep it running, it'll do.

 

[Volpone]

They did until there was a crackdown on Craigslist Personals.

Why doesn't anyone want me to be happy?