Anyone here know about small engines?

[FLRon]

Removed the air filter and she still doesn't want to pull.

[Bob Womack]

Originally Posted by FLRon

Removed the air filter and she still doesn't want to pull.

Pull the plug and let it air out. Replace the plug and leave the filter off and try. If the only thing that relieves the back pressure is removing the plug, it isn't vapor lock.

Bob

[HodgdonExtreme]

Improper ignition timing (too advanced/too early) can cause increased effort on the pull rope, or even jerking it out of your hand.

However, it should be easy enough to rotate the engine's crankshaft thru one and a half rotations prior to the "hard spot" of the pull... Ignition timing/spark advance doesn't explain why the engine is very difficult to rotate throughout the entire suck/squish/bang/blow cycle.

I suspect you have an issue in the recoil assembly - that works ok when there is very little load/force on it (when you pull the rope without sparkplug installed), but gets cocked or jammed when the engine isn't just free-wheeling.

Originally Posted by Bob Womack

There is a phenomenon called "vapor lock" that occurs in engines as well...

Your description of vapor lock is incorrect. Vapor lock is a phenomenon where fuel boils in the carburetor, fuel lines, fuel rails or fuel pump - and thus does not flow at the correct rate (or at all) to satisfy the engine's fueling needs - which ultimately results in an engine happy to crank, but won't run.

https://en.wikipedia.org/wiki/Vapor_lock

[AgedPassion]

Originally Posted by FLRon

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?

__________________________________________________ ____

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?

_______________________________________________

Hi FLRon,. (just taking a short break, from outside working)
... (sorry for long post)..

I too, have an OHV 4-Stroke 163cc Honda engine, on a Push-mower I use for ‘Trim-cutting’.. I have just under 2 acres to mow.. (not counting House, Shop, buildings, Vehicles (many) etc..)

I saw your Post yesterday, and thought I might add a few things that May possible help.. ( I moved several vehicles, and some lumber, and DID some trim mowing today.


SO,,, I thought I would just Check to see if I could Replicate several issues you are having on ‘my’ mower. (less than 10 min total time). Since I already had mower outside.

Your issues STILL appears to Me, to be a Hydro-Lock condition.. .. Fluids are NOT able to be Compressed!.. Mixtures w/ significant amount or ‘Air’, definitely ARE!,.

It still ‘Sounds’ to me like a ‘raw Fuel’ HydroLocking situation, in the Engine Cylinder, to me..

I will guess, when Mower was raised on Both Sides, raw Fuel, was possibly introduced into the Cylinder.. …
Perhaps,, also, the Carb-‘Float’ did not fully Seat, allowing the Needle Valve, to NOT fully shut, and allowing raw fuel into cylinder.. (one possible Scenario).


Anyway….
What ‘I’ would do, to Helpfully Isolate some of the Issues..

IF, I was in your Situation, ‘I’ would, (1) Shut OFF Fuel-Control in-line Valve, (2) REMOVE the Spark-Plug,, (DON’T try to Pull Starter-Rope, w/o GROUNDING Plug-Wire, or moving Spark-Plug Wire good distance AWAY from Metal, for Fire-hazard Safety!)…

(3) Lift the Entire Mower by Handle-Bar FORWARD, so complete Mower is in FULL-VERTICAL Position, w/ some type of low container, to potentially ‘Catch’ any Fuel from Cylinder..


…FWIW… I just Performed this EXACT scenario, on my 4-stroke OHV Honda lawn Mower..
(some fuel DID leak from Carb,, remember, my Fuel-Valve was Closed, so ONLY the Fuel in Carb Bowl was what leaked out)..

I Re-installed spark-Plug, mower Stared on Second-Pull and was Running PERFECT… (Carb Fuel-Bowl, was probably mostly Empty)…
ALSO noting, NO Blue smoke upon start-up,, Confirming NO Oil had Leaked into Cylinder..

You may Possible want to Try this quick Diagnostic-procedure, to Completely Isolate ANY Hydro-Locking Issues..


(Not saying your Starting Issues, is Not related to the Starter ‘Pawls’ in Rope Starter mechanism...
* Isolating ONE Potential Issue at a Time, will generally Lead to a Successful Remedy..



FWIW – ‘Vapor-Lock’ is Definitely NOT the Issue.

Generally ‘Vapor-lock’ is a problem caused by liquid fuel changing state to gas, while still in the fuel delivery system of gasoline-fueled internal combustion engines. ...
The fuel can Vaporize due to being heated by the engine, (or by local climate or due to a lower boiling point at high altitude).
Vapor-Lock happens when Fuel BOILS in the Carburetor Bowl(s), or in the METAL Fuel-Lines (against Hot Engine parts, more Common)..
Vaporized fuel creates back pressure in your Fuel-System and Fuel-LINES, and prevents gas from getting to the Combustion Chamber of the engine.



Another just whatever, FWIW,, (now age-70).. previously,, I was ASE Master-Certified Auto Technician, w/ Many years Machine Shop experience.. 20 years Chevrolet Dealership, w/ over 50 years Total.. Also, Race-Engine Builder (Drag-Race), and Race-Car Fabricator. (Still,doing it, some)..(Frame-Rail back-half Suspension, etc. etc.) w/ Stick, Mig, & Tig Welding) etc. etc.. also w/ older SouthBend Lathe & Vertical Mill)..
(Yes, I also have various experience w/ Assorted other Internal-Combustion Engines.) I MUCH prefer 4-Stroke, though have had MANY 2-Cycle engine too.)
Plus, several More Intensive Hobbies!.. (including Guitar (of course) since 1965) fwtw too..


All the Best,
Hope some of this may help Isolate some of your Issues, Earl
__________________________________________________ ___

[FLRon]

Thanks to all for the thoughtful responses. On a whim I decided to pull the dipstick and do the “sniff test”. Sure enough, there’s gas in the oil.

So tomorrow I’ll drain the now worthless oil and refill with fresh oil and take it from there.

Edit to say that I will pull the plug and tip the mower vertically as suggested.

[AgedPassion]

Originally Posted by FLRon

Thanks to all for the thoughtful responses. On a whim I decided to pull the dipstick and do the “sniff test”. Sure enough, there’s gas in the oil.

So tomorrow I’ll drain the now worthless oil and refill with fresh oil and take it from there.

Edit to say that I will pull the plug and tip the mower vertically as suggested.

__________________________________________________ _____

Hi Ron,.

Just got back in bit after 8pm.. thought I would check your Progress.

* Good Thought on Checking Oil..

I had a Short Statement, in my first Post, though it got ‘Deleted’ when I Highlighted text, & adding More info in One of my Paragraphs….. IT dealt with checking for an bit ‘OverFull’ Oil level, or a Raw Gasoline Smell on the Oil Dipstick.
* Good for You, for Thinking of this quick and easy Diagnostic procedure!..


Yes, it can be Difficult (at times) diagnosing Engine or Car Symptoms, (or Guitars, or Anything for that matter),, through ‘word or phone’ correspondence) w/o an ACTUAL Hands-On approach..


I will Speculate again, the ‘Float’ in carb Sticking/binding,, OR, possibly small bit of ‘debris’ in between Needle & Seat in Carb.


* IF, you wish to SEE, IF in Fact, that there IS Raw-Fuel in the Cylinder, causing the ‘Hydro-Lock’ Condition, You will NEED to TEST This, While the Engine Scenario is IN the 'SAME' HARD-TO-PULL or CAN’T-PULL 'Condition' as before, w/ the Hard or Can't Pull, Starter Rope Condition.. , ...

AFTER Simulating & Confirming your ORIGINAL 'Hard/Can't Pull' condition,
THEN,
Remove the Front-Mounted Spark Plug, & carefully Raise/Tilt(on the Front Wheels), the Complete Mower VERTICALLY, for approx 5-10 seconds.. .. (Having a low flat container of sorts, approx 12" x 12" or so, to possibly catch/verify raw Gasoline..
to Verify the 'Hydro-Lock' condition, w/ Raw-Gasoline in the Engine Cylinder.
*(Noting: as written in my First Post,, "…FWIW… I just Performed this EXACT scenario, on my 4-stroke OHV Honda lawn Mower..
(some fuel DID leak from Carb,, remember, my Fuel Shut-off Valve was Closed, so ONLY the Fuel from Carb Bowl was what leaked out, through Breather/filter area)..
I Re-installed spark-Plug, mower Started on Second-Pull and was Running PERFECT… (Carb Fuel-Bowl, was probably mostly Empty, requiring the 'Additional' Rope Pull)…
ALSO noting, NO Blue smoke upon start-up,, Confirming NO Oil had Leaked into Cylinder.. on my replication Experiment.



The Thin, very Low Viscosity of Gasoline, CAN be Forced (slowly) by way of Compression, (depending on Volume) Through the Piston’s RINGS, in a COLD Engine Cylinder.



Regardless, To “Me”, I would at this Point, REMOVE Carb, Remove Carb Fuel-Bowl from Carburetor, Carefully remove FLOAT (I will speculate again, the Float will be a White PLASTIC Circular-Type,, Remove Float-Pin, and Carefully LIFT ‘Needle’ and Float, from Carb.. (being Careful of the ‘Needle’ Hold-in-place, very small SPRING.. Check carefully for debris, after 'Needle' is Removed.. Flush and Blow-out as needed.
*alsp Checking & Cleaning any Debris, from Bottom of Carb Bowl.. & Reassemble.
(fairly Quick and Easy, depending on mechanical abilities)


OR, Purchase NEW CArb,, Not too expensive, from Amazon-Prime.. (applicable Numbers ‘Should’ be on carb)

Or, last resort, take to your Dealer/Repair business.


Hope this Helps..

You are Almost There, using your Almost New HONDA Mower again!

All the Best, Earl
__________________________________________________ ____

[FLRon]

Originally Posted by AgedPassion

__________________________________________________ _____

Hi Ron,.

Just got back in bit after 8pm.. thought I would check your Progress.

* Good Thought on Checking Oil..

I had a Short Statement, in my first Post, though it got ‘Deleted’ when I adding More info in One of my Paragraphs….. IT dealt with checking for an bit ‘OverFull’ Oil level, or a Raw Gasoline Smell on the Oil Dipstick.
* Good for You, for Thinking of this quick and easy Diagnostic procedure!..


Yes, it can be Difficult (at times) diagnosing Engine or Car Symptoms, (or Guitars, or Anything for that matter),, through ‘word or phone’ correspondence) w/o an ACTUAL Hands-On approach..


I will Speculate again, the ‘Float’ in carb Sticking/binding,, OR, possibly small bit of ‘debris’ in between Needle & Seat in Carb.


* IF, you wish to SEE, IF in Fact, that there IS Raw-Fuel in the Cylinder, causing the ‘Hydro-Lock’ Condition, You will NEED to TEST This, While the Engine Scenario is IN the 'SAME' HARD-TO-PULL or CAN’T-PULL 'Condition' as before, w/ the Hard or Can't Pull, Starter Rope Condition.. , ... before Removing the Front-Mounted Spark Plug, & carefully Raising/Tilting (on the Front Wheels) the Complete Mower VERTICALLY, for approx 5-10 seconds.. .. (Having a low flat container of sorts, approx 12" x 12" or so, to possibly catch/verify raw Gasoline..
to Verify the 'Hydro-Lock' condition, w/ Raw-Gasoline in the Engine Cylinder.

The Thin, very Low Viscosity of Gasoline, CAN be Forced (slowly) by way of Compression, (depending on Volume) Through the Piston’s RINGS, in a COLD Engine Cylinder.



Regardless, To “Me”, I would at this Point, REMOVE Carb, Dissemble Fuel-Bowl, Carefully remove FLOAT (I will speculate again, the Float will be a White PLASTIC Circular-Type,, Remove Float-Pin, and Carefully LIFT ‘Needle’ and Float, from Carb.. (being Careful of the ‘Needle’ Hold-in-place, very small SPRING.
*Checking & Cleaning any Debris, from Bottom of Carb Bowl.. & Reassemble.
(fairly Quick and Easy, depending on mechanical abilities)


OR, Purchase NEW CArb,, Not too expensive, from Amazon-Prime.. (applicable Numbers ‘Should’ be on carb)

Or, last resort, take to your Dealer/Repair business.


Hope this Helps..

You are Almost There, using your Almost New HONDA Mower again!

All the Best, Earl


__________________________________________________ ____

Ok I’m a little confused now Earl. Your instructions say “before removing the front mounted spark plug”....how would anything drain out unless the plug is removed? Am I not understanding you correctly?

[AgedPassion]

Quote by FLRon :
"Ok I’m a little confused now Earl. Your instructions say “before removing the front mounted spark plug”....how would anything drain out unless the plug is removed? Am I not understanding you correctly? "


Hi Ron,.

Sorry, You are Correct.. My Fault on the wording..

I Mis-edited, when I added additional info to that particular paragraph.



I will attempt to edit and correct my previous post..


Wishing the Best with your Repair, Earl.
______________________________________________

[AgedPassion]

Hi Ron,

Just another Short, Quick bit of info.. (late lunch break for me)

(in My experiences) .. Concerning the AMOUNT of LIQUID-Fuel, to Cause a Hydro-Lock condition, The Volume amount Can, and Will Probably be a quite Small Amount, as Relating to this Small Engine Cylinder’s Volume.

I will speculate approx in the One-Ounce range, (in this Honda 163cc engine) which will amount to approx 29.6 cc’s. (a bit Over 18 % of the Cylinder Volume).

Again only Speculating, approx 18% LIQUID FUEL, in a Piston Cylinder, WILL Cause a Hydro-Locking Condition.


Specs On the HONDA 163cc Engine.. (just checked) the Cylinder Bore is Only 2.5 inches Diameter, (w/ a Crankshaft-Stroke of 1.7 inches).. Compression-Ratio is stated at 8.5:1 ratio.



… To Summarize, I Just wanted to make Note, the Volume of Liquid-Fuel, causing a Hydro-Locking condition, can and Will, probably Only be a Small amount.. if you desire to Check this aspect..


Hope this will help some..

(I was able to Edit my earlier Post suggestions (post #21), on the confusing Spark-Plug removal sentence, in the Diagnosis sequence)


Wishing you Best, with your Diagnosis and Repair.
Earl
________________________________________________

[FLRon]

Well, the mystery has been solved. I just picked the mower up from the dealer(mower is still under warranty). The problem was the valves needed a major adjustment. I regret that I could not speak to the tech that did the work because I do not understand how/why this happened after 3.5 years of trouble free use.
At any rate the mower starts as easily as it did when it was new, so for now I consider it to be repaired.
Thanks again for the helpful suggestions and comments.

[endpin]

My Honda GCV160 engine had a problem with the overhead valve timing belt jumping a tooth. I had taken the valve cover off several times and realigned the belt to the correct timing marks, but it would jump a tooth again every time I "fixed" it.

After researching on the internet I found it was a common problem and replaced the cheap stamped aluminum valve cover with a cast aluminum version.

The new OHV cover has a belt guide integrated into the casting that keeps the belt from jumping the valve cam gear. I have never had a problem with it since.

I couldn't believe they would have produced however many thousand of these things with a known problem like that.

[Bobby1note]

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?

You may find your answer here;
youtube.com/watch?v=u-axxCnGjIw&feature=emb_logo