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Honda GCV160 Mower "kickback" when starting

#1

E

enzololajett

I have a Honda HRR2169vya mower with a GCV160 engine. Lately it has started kicking back when I attempt to start it. It seems to be getting worse and nearly broke my arm earlier this week. Typically, I see this when the timing is off, possibly due to a slipped or broken flywheel key. I pulled the flywheel and the Woodruff key is perfect.

If I pull the spark plug the mower spins freely. If I pull it over a few times with no plug it will start easily, first pull when I replace the plug. If I shut it off it will immediately exhibit kick back. I can (so far) always get it started, but I now wear heavy gloves and must be very careful. It seems as though the mower is experiencing a sort of "hydro lock" rather than spark timing issue. With the wire pulled from the spark plug, I still get kick back.

I suspect a timing or valve lash issue as I'm pretty sure there's a timing belt for the cams and a lash adjustment that's critical. I'm hesitant to pull the cover as the mower still has a few months left on warranty. I don't want to void it by doing obvious do-it-yourself stuff that would probably be obvious if I had to re-glue the valve cover. There is no authorized Honda shop near to my home where I could get warranty help.

If I was 100% sure that my issue was something easily adjusted under the valve cover, I might just take a chance at a self repair even if it would void my warranty.

Anyone had similar issues with this engine? Any advice would be welcome.


#2

B

bertsmobile1

I the engine just kicks back and the flywheel key is intact then the decompression is not working.


#3

robert@honda

robert@honda

I don't want to void it by doing obvious do-it-yourself stuff that would probably be obvious if I had to re-glue the valve cover. There is no authorized Honda shop near to my home where I could get warranty help.

If I was 100% sure that my issue was something easily adjusted under the valve cover, I might just take a chance at a self repair even if it would void my warranty.

Anyone had similar issues with this engine? Any advice would be welcome.

You won't void your warranty if you attempt repairs. Now if your repairs cause other things to fail or break, those repairs would not be covered under warranty.

Now it sure sounds like a good old fashioned case of hydro lock due to engine oil getting into the cylinder. This can easily happen if you tip the mower on the wrong side (air cleaner side DOWN), as this allows oil to flow into the air cleaner/carb and into the cylinder. Trying pulling the spark plug out and give the engine some spins. Inspect the air cleaner / carb for any signs of oil intrusion.

If it is more involved (decompressor or other internal engine issues (slipped timing belt?) , get a shop manual to guide you through all the details...Honda sells paper copies on Amazon and eBay (free shipping):

Honda Power Equipment Shop Manuals on eBay
Honda Power Equipment Shop Manuals on Amazon


#4

E

enzololajett

Thanks for the responses. As I mentioned in my original post, I've pulled the spark plug and noted that the engine spins freely. I can get it started and there is no indication of oil in the cylinder (exhaust is clean) when running. The engine has never been turned on its "left" side as I know this will allow oil to possibly foul the cylinder. If I run the engine, shut it off, and pull the starter within a few seconds, it will still kick. So, I'm pretty sure it is a mechanical problem with cam timing, or, more likely, a decompression system problem. I was hoping for help in correcting the decompression system problem, but I guess I'll pop for a copy of the shop manual.

It's my impression that the decompression system causes the intake valve to slightly open just before TDC at slow cranking speeds. Is there some way some part of the decompression system is "sticking" due to being dirty (sludge? carbon?), or can ethanol (E10) fuel cause any problems? Can improper valve lash add to the problem? Are parts of the decompression system accessible from inside the valve/cam cover, or is further disassembly required?

If anyone has successfully corrected problems with the decompression system I'd welcome any tips you have to offer. Thanks.


#5

robert@honda

robert@honda

It's my impression that the decompression system causes the intake valve to slightly open just before TDC at slow cranking speeds. Is there some way some part of the decompression system is "sticking" due to being dirty (sludge? carbon?), or can ethanol (E10) fuel cause any problems? Can improper valve lash add to the problem? Are parts of the decompression system accessible from inside the valve/cam cover, or is further disassembly required?

The decompressor is fitted to the camshaft pulley, and a light spring holds a curved metal rod into a position that holds open the exhaust valve. When you pull the starter handle, the valve remains open to ease starting effort. Once the camshaft pulley reaches a specific speed, the centrifugal force overcomes the spring and the metal rod moves out of position, allowing the camshaft to fully control the exhaust valve operation (full compression).

Should the spring fail, or if there is wear/damage around the metal rod, it can get 'stuck' in the wrong position, allowing for full compression at all times, regardless of the engine speed. This of course can result in a kick or hard starting effort.

All the parts are accessible under the cylinder head cover. Remove and inspect the rod, spring, and look carefully for debris, damage to the pulley, or wear that could cause the rod to stick in the full compression position.

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#6

T

tomocar

Hello - can I re-open an older thread like this?

I have a similar problem on a GCV 190 - kicks back so hard the starter handle whips me in the stomach and it hurts!

I couldn't get the flywheel nut off so I thought I'd check the valves and decompression spring thing first, and found that the exhaust valve rocker was actually broken - it was flopping so loose I don't think the exhaust valve could have been opening at all. (And the decompressor looked fine.) Anyway, went to the Honda parts store and bought the new rocker, and asked the guy: what could have caused this? Should I suspect some other problem or could it just be this? He said it's probably just this - replace it and it should be fine. So did that - and dang it, I still get the gut-punching kick back.

So I'm back to usual suspect #1 - the flywheel key... So how do I get that nut off? I've been trying with a rubber-belt-wrap wrench-thing around the flywheel and a socket wrench on the nut, but with all my strength I can't get it to budge. Any suggestions? It's not reverse-threaded is it?

Thanks!
Tom


#7

robert@honda

robert@honda

So I'm back to usual suspect #1 - the flywheel key... So how do I get that nut off? I've been trying with a rubber-belt-wrap wrench-thing around the flywheel and a socket wrench on the nut, but with all my strength I can't get it to budge. Any suggestions? It's not reverse-threaded is it?

Thanks!
Tom

I'm guessing you don't have access to an impact wrench, as that would surely make for quick removal.

Having a helper hold the strap wrench while you turn the socket?

You can dramatically increase the mechanical advantage with a longer ratchet (a.k.a.'breaker bar'). As the great Greek mathematician Archimedes said, 'Give me a lever and a place to stand and I will move the earth.'


#8

T

tomocar

Thanks Robert, but I am embarrassed to say I made a mistake. Indeed the broken rocker arm was the problem - I just messed up the gap setting procedure - I must have been off my rocker! :laughing:

So I don't need to take the flywheel off - motor runs fine now.

BTW: to anyone else reading this thread, so this is another thing that can cause one hell of a kick-back: broken rocker.


#9

D

DPDISXR4Ti

I have a similar problem on a GCV 190 - kicks back so hard the starter handle whips me in the stomach and it hurts!

Same story with me - I've got a GCV 190 on my Homelite 3100 PSI pressure washer - the kick-back wants to rip the handle out of my hand even with a death-grip on it. Does everything that Robert posted above regarding the 160 hold the same for the 190?


#10

G

golfergordy

I picked up a used HR215 with the same kick-back problem. I found the valves to be out of adjustment, and re-setting the valves to the proper gap solved this problem.


#11

D

DPDISXR4Ti

I picked up a used HR215 with the same kick-back problem. I found the valves to be out of adjustment, and re-setting the valves to the proper gap solved this problem.

I haven't had a chance to investigate further yet, so thanks for the confirmation on the likely cause. Funny enough, I have a non-runner HRA214 that I'm sorta "parting out" - got it for free, but not enough time to bother with it when I have three other mowers that work.


#12

D

DPDISXR4Ti

After having the pull-cord break on me the other day, I decided today I would work on this thing. Got the cam cover off with a bit of effort. That damn Hondabond is great until you need it to come un-done!

Rotated to TDC and promptly found that the exhaust valve lash was over .63mm - the thickest feeler gauge I have - it was probably about 4x over spec! So I've just now set it to .20mm.

Not mentioned above, but the intake side should be set around .15mm. Off to do that now.

Should I be checking anything else?


#13

Scrubcadet10

Scrubcadet10

A common problem is the exhaust rocker arm can crack, so look for any hairline splits so you dont have to do this over again


#14

D

DPDISXR4Ti

A common problem is the exhaust rocker arm can crack, so look for any hairline splits so you dont have to do this over again

I took the rockers off and inspected them - they both looked good.

The intake lash was only a little over - about .25mm - so I set that to .15mm and buttoned things back up.

Now I need to figure out how to set the rewind on the pull cord. I presume there's some process of setting a pre-load.


#15

B

bertsmobile1

Take the string off
Wind the pulley to the end of it's travel.
Rotate the pulley backwards till the holes line up then replace the string.
This way the string will end just before the spring bottoms out.


#16

D

DPDISXR4Ti

Take the string off
Wind the pulley to the end of it's travel.
Rotate the pulley backwards till the holes line up then replace the string.
This way the string will end just before the spring bottoms out.

Thanks! Got it done.

Just started it up on two pulls. Started easier and no kick-back! I think I'm calling it fixed!

Two footnotes for anyone doing this in the future...
1) The nut for the rockers requires a 9mm socket.
2) You'll need some RTV for re-sealing the cam cover. Too bad they didn't use a re-usable rubber gasket as it would make life easier.


#17

D

DPDISXR4Ti

Ran the power-washer again yesterday and every time now it started easily on the first pull. I can't believe I fought with this issue for so long!


#18

hppants

hppants

In post #5 of this thread, I'm trying to figure out which position the decompressor needs to be in the slot with the motor at rest. Looking at it from the top (as shown), mine is all the way to the right. If I slide it to the left, it does retract (very slowly) back to the right.

My exhaust valve has ZERO clearance to it.

Is my decompressor/cam pulley OK?


#19

D

DPDISXR4Ti

My exhaust valve has ZERO clearance to it.

Unless someone has already been in there and mucked with the exhaust lash, I'd say you have some other issue. I'm saying this since typically the clearance increases with use, not decreases. I don't recall enough to tell you how the decompressor works or is located, but I think that's a good place to look since I'm assuming it leaves the exhaust valve hanging open at start-up.


#20

hppants

hppants

On every "non-hydraulic" valve train that I am familiar with, the clearance typically decreases with wear, as the valve seats and valves wear over time and use. None the less, I do have NO clearance on the exhaust valve now.

No one has been into this motor, as I bought it new.

If I slide the "decompressor" in the slot to the left, hold it there (because the very weak spring will return it to the right), and turn the motor, the exhaust valve clearance does not change (still holds at zero). So I'm kind of perplexed as to whether or not the decompressor is working properly or not.

Mower won't start. Won't fart or run on carb cleaner. I've cleaned out the carb (it's clean - trust me). I've got fire. I've got no compression, but I'm not surprised since the exhaust valve has no clearance. I have NOT pulled the flywheel to see if the key has sheared.

(scratching my head)

Thoughts?


#21

H

Honda Tech

Same story with me - I've got a GCV 190 on my Homelite 3100 PSI pressure washer - the kick-back wants to rip the handle out of my hand even with a death-grip on it. Does everything that Robert posted above regarding the 160 hold the same for the 190?
Yes, basically same engines, different displacements.


#22

G

golfergordy

hppants, Having 0 exhaust valve clearance could cause poor compression, so why don't you just adjust the valves to specs and see if that solves your starting problem.


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