Anyone here know about small engines?

FLRon · #1 10-16-2020, 08:26 PM

I’m wondering if I’ve damaged the engine on my Honda mower today. After turning it on its sides to remove the rear wheels and do some repair work related to the rear wheels not turning when pulling the mower in reverse, when I went to start the mower I couldn’t pull the starter rope. Once it even jerked the rope out of my hand! I should note that I also changed the oil in the mower.

After several attempts to pull the rope, it finally started. So I figured whatever caused it went away. Wrong! I ran out of gas and when I added a bit in order to finish mowing, the starter rope wouldn’t pull again. After a few minutes of pulling it just a bit, it fired up again.

Since my mower has started on the 1st pull from the time I unboxed it, I’m concerned that something is very wrong now.

Does anyone have an idea about what’s going on here?

1neeto · #2 10-16-2020, 08:58 PM

Sounds like hydro lock. Did you drain the oil before putting the lawnmower on its side?

FLRon · #3 10-16-2020, 09:27 PM

Quote:

Originally Posted by 1neeto

Sounds like hydro lock. Did you drain the oil before putting the lawnmower on its side?

Yes I did. Was that the wrong thing to do?

Edit to say I did some research and this sounds like hydrolock. Which I don’t really understand because I drained the oil when I tipped the mower on its side. After repairing the first wheel I flipped it up on the other side, but all the oil had drained out of it by then. I also had the fuel valve OFF.

1neeto · #4 10-16-2020, 09:50 PM

Quote:

Originally Posted by FLRon

Yes I did. Was that the wrong thing to do?

Edit to say I did some research and this sounds like hydrolock. Which I don’t really understand because I drained the oil when I tipped the mower on its side. After repairing the first wheel I flipped it up on the other side, but all the oil had drained out of it by then. I also had the fuel valve OFF.

Try and remove the spark plug and pull on the cord and see if any oil or fuel spits out the spark plug hole.

FLRon · #5 10-16-2020, 09:59 PM

Quote:

Originally Posted by 1neeto

Try and remove the spark plug and pull on the cord and see if any oil or fuel spits out the spark plug hole.

Will definitely try that tomorrow. Thank you!

FLRon · #6 10-17-2020, 12:00 PM

Well, pulling the plug out and then pulling the starter rope didn't reveal anything to me. Without the plug, the rope pulled as easy as normal of course, but produced no oil from the spark plug hole.
I'm thinking it's back to the dealer as it's still under warranty.

Earl49 · #7 10-17-2020, 12:15 PM

Ron, I’m not surprised that it wasn’t hydraulic lock - a cylinder full of oil. You were able to run the engine afterward, which eliminates that possibility. My guess is that a ratcheting mechanism in the retractable pull cord is either broken or a toggle fell out of its normal position when you turned the mower on its side. It happened to me on a new snowblower once. Should be no big deal to fix......

H165 · #8 10-17-2020, 12:22 PM

Quote:

My guess is that a ratcheting mechanism in the retractable pull cord is either broken or a toggle fell out of its normal position when you turned the mower on its side.

+1

- not an engine problem because you've already eliminated that by running it.

FLRon · #9 10-17-2020, 01:19 PM

Well something broken in the pull cord mechanism beats an engine failure any day of the week! I’ll check that out and thanks for mentioning it. I never would have thought of that.

1neeto · #10 10-17-2020, 06:17 PM

Quote:

Originally Posted by Earl49

Ron, I’m not surprised that it wasn’t hydraulic lock - a cylinder full of oil. You were able to run the engine afterward, which eliminates that possibility. My guess is that a ratcheting mechanism in the retractable pull cord is either broken or a toggle fell out of its normal position when you turned the mower on its side. It happened to me on a new snowblower once. Should be no big deal to fix......

It was late and was a few beers in when I first responded. Somehow I totally missed reading he managed to run the engine before it was hard to start again. All I read was: “turn it on its side and couldn’t pull the cord”. [emoji23]

endpin · #11 10-17-2020, 08:34 PM

My Honda GCV160 engine mower does that occasionally. I am pretty sure it is compression related as you can feel the crank move until you hit the compression stroke and then it locks up.

If it does that every time you start and also kicks back on the rope, it is usually the timing belt has jumped a notch.

FLRon · #12 10-18-2020, 12:45 PM

Quote:

Originally Posted by endpin

My Honda GCV160 engine mower does that occasionally. I am pretty sure it is compression related as you can feel the crank move until you hit the compression stroke and then it locks up.

If it does that every time you start and also kicks back on the rope, it is usually the timing belt has jumped a notch.

I have the GVC 190 engine. What makes me think it’s compression related is when I pull the spark plug the rope pulls very easily. Put it back in and it’s super hard to pull it even a few inches.

Bob Womack · #13 10-18-2020, 01:40 PM

There is a phenomenon called "vapor lock" that occurs in engines as well. It is a function of too much fuel having been vaporized into the air so that the combination won't ignite and nears or arrives at the point of incompressability. When engine is in vapor lock behaves exactly as you experienced. It is a function of the temperature and water content of the air and the temperature of the engine. It can also be encourage by a poor air/fuel mixture and that in turn may be caused by a dirty air filter impeding air flow.* The liquid form of gasoline won't burn - only the vapor will. Vapor lock begins when you don't get enough air for for ignition. Because exhaust ejection is rarely complete, the fuel percentage begins to build in the cylinder with each attempt at a start. You end up with a mixture that is very much like dewy air in the early evening (the droplets of dew can be seen with a flashlight) and the compression phase becomes really tough to accomplish. Really, the only way to beat it is to open up the cylinder and let the volatile fuel/air mixture out or simply let the engine cool.

Bob

* Once on a hot day I hit a dusty spot with the mower and threw up a cloud. I stopped the engine for a second. When I tried to start it back up, it wouldn't start and then didn't want to pull through. I checked the air filter and found that the cloud of dust had contaminated it badly enough that it impeded the ai flow. I let the engine cool and left the air cleaner off and it started. I replaced the air filter and it wouldn't start and then stopped pulling through again. I removed and cleaned the air filter, re-oiled and replaced it, and things worked fine.

FLRon · #14 10-18-2020, 03:00 PM

That’s the thing Bob. All of this took place on Friday afternoon. Saturday morning I tried to pull the starter rope and couldn’t. As I’ve mentioned a couple of times, I removed the plug and the rope pulls as easily as it did when the mower was new. No oil, water, or other substances came out of the plug hole. I put the plug back in, the engine is cold, and the rope is next to impossible to pull.
This can’t be a vapor lock, can it?

Bob Womack · #15 10-18-2020, 03:30 PM

Quote:

Originally Posted by FLRon

That’s the thing Bob. All of this took place on Friday afternoon. Saturday morning I tried to pull the starter rope and couldn’t. As I’ve mentioned a couple of times, I removed the plug and the rope pulls as easily as it did when the mower was new. No oil, water, or other substances came out of the plug hole. I put the plug back in, the engine is cold, and the rope is next to impossible to pull.
This can’t be a vapor lock, can it?

After letting it rest, pop off the air cleaner and see if it will pull through and/or start. That will be the test.

Bob