Pressure washer engine won't hardly turn with spark plug installed

[FTG-05]

Remove the spark plug and it pulls easy. As you put the spark plug in and start turning it in, it gets progressively harder and harder to pull the engine to start it. When it's torqued down, it's almost impossible to pull the engine.

It's a Honda 160 cc GC series engine (see pic). It's installed on a "Pressure Wave" DeVilbiss Air Power Co. pressure washer that my wife got on an estate sale; Model number 2225CWH-2.

The oil, air filter and spark plug look like they've never been run.

Pics:

 

[Buckgnarly]

Are you releiving pressure on the pump side. Mine pulls hard unless I pull the trigger on the gun to releive pressure.

 

[FTG-05]

Are you releiving pressure on the pump side. Mine pulls hard unless I pull the trigger on the gun to releive pressure.

I just got it, so haven't even hooked the pressure washer hose or gun up to it yet.

 

[Milton Shaw]

Should not ever try to run pressure washer without water on and running through the hose first. The pump burns up very shortly (just a minute or two) with no water flow. The previous owner might have done that and already ruined the pump. Not much way to tell without removing the pump and trying it.

 

[FTG-05]

Well ****! The engine serial number is GCAH-1244376 and that serial number is not recognized by the online Honda parts store, which means (I think) that it was made before 2004. Hence parts are only available from Honda dealers. http://peparts.honda.com/engines#/serial

According to this 2011 post on the MyTractorForum, the problem is with the cam: https://www.mytractorforum.com/44-s...-honda-gc160-compression-release-problem.html

Do we have any small engine repair or Honda small engine repair people on this site?

Thanks,

 

[kythri]

Are you releiving pressure on the pump side. Mine pulls hard unless I pull the trigger on the gun to releive pressure.

Mine does the same.

 

[Old Man Roger]

I didn't read the link you posted, but my first thought was the valves are both closed.

 

[redmondjp]

It sounds like the compression release feature isn't working properly, which on many engines consists of a small movable piece on the cam, that holds one of the valves open a bit during the compression stroke, until the engine starts running.

 

[L.Cheapo]

Do you have a compression gauge? It would be interesting to see what it says.

 

[Bluejoe]

Hello if it’s compression release then you would have to probably change the whole cam. You can check valve clearance. If exhaust is not opening it won’t release air. Then you might have hydro lock. But it seems you removed spark plug already and nothing came out meaning fuel which bypassed carb filling block and cylinder.

 

[Show7d3]

Sounds to me like a compression release problem. The cam has a bump on it to open one of the valves slightly to bleed off some compression. Check valve clearance, rocker arms for cracks and rocker pins for wear. Had a push mower in the shop last week that would yank the rope out of my hand and one of the rocker arms was cracked. Over the years I have seen several of those engines with wear where the rocker pin went in the "head". For some reason all were pressure washer engines. For those of you wondering about the quotation, on the GC engines the crankcase splits diagonally and the head is part of the cylinder.

 

[FTG-05]

Should not ever try to run pressure washer without water on and running through the hose first. The pump burns up very shortly (just a minute or two) with no water flow. The previous owner might have done that and already ruined the pump. Not much way to tell without removing the pump and trying it.

OH! That's good to know!

I'm pretty sure it's the cam/unloader issue.

Anyone here have the cam part number for this serial number engine: GCAH-1244376? I've already seen one YT video on how to change it out, should take more than 5 minutes or 5 hours, whichever is longer.......

Just need to know the correct CAM part number.

Thanks,

 

[bpjr]

I don't know if Honda is the same but...some Briggs and Stratton riding mower engines get difficult to turn over when the valves are out of adjustment. Don't laugh, its a fact. I have two 17hp on riders and been there and done it. Personally didn't believe it at first but adjusting valves does the trick. These engines also have a bump on the cam that is supposed to act as a compression release for starting.

 

[rustbucket5]

my guess is valve adjustment. one time i accidentally set the valve lash wrong on a honda (something like 30 thou instead of .30mm, read the wrong scale) and it was hard to pull and would pull the handle out of your hand. its also common for the exh rocker to crack on the GC series of motors which will cause the same issue

 

[AmishFury]

Mine does the same.

the one i've been trying to fiddle with at work is the same way... i thought the engine was fuckered after i got it to fire for 3 seconds and it wouldn't pull after

pulled the trigger on the wand and i could get the thing to pull again

 

[FTG-05]

I don't know if Honda is the same but...some Briggs and Stratton riding mower engines get difficult to turn over when the valves are out of adjustment. Don't laugh, its a fact. I have two 17hp on riders and been there and done it. Personally didn't believe it at first but adjusting valves does the trick. These engines also have a bump on the cam that is supposed to act as a compression release for starting.

my guess is valve adjustment. one time i accidentally set the valve lash wrong on a honda (something like 30 thou instead of .30mm, read the wrong scale) and it was hard to pull and would pull the handle out of your hand. its also common for the exh rocker to crack on the GC series of motors which will cause the same issue

So how do I check for this, and assuming they are out of adjustment, how do I readjust them?

Thanks,

 

[LawnBoy-5247]

You will need to pull the valve cover. Once it is off you will turn the engine over untill one valve is fully open. Then loosen the locking nut and use the correct feeler gauge to adjust the closed valve to the proper clearance. Repeat that for the other valve. Also in order to get parts look on the side of the engine block near the dipstick there will be another code engraved near the s/n that is the spec for the engine. Use partstree to look up parts as it is the most reliable database of parts diagrams.

Sent from my LGLS991 using Tapatalk

 

[LawnBoy-5247]

The code will be something like QHAJ or PKA.
Type it into partstree like this to find your engine- Honda GC160 QHAJ

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[rustbucket5]

you can find youtube videos that will show you what you need and how to do it

 

[FTG-05]

The code will be something like QHAJ or PKA.
Type it into partstree like this to find your engine- Honda GC160 QHAJ

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Looking on that site as we speak. There is another 3 digit number but I can barely read it. I'll look again tomorrow and then order the part. I'll replace the cam and retune the valves (if needed) at the same time.

Thanks!

 

[LawnBoy-5247]

I would try to adjust the valves first before you buy a cam that way you don't buy unneeded parts.

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[FTG-05]

You will need to pull the valve cover. Once it is off you will turn the engine over untill one valve is fully open. Then loosen the locking nut and use the correct feeler gauge to adjust the closed valve to the proper clearance. Repeat that for the other valve. Also in order to get parts look on the side of the engine block near the dipstick there will be another code engraved near the s/n that is the spec for the engine. Use partstree to look up parts as it is the most reliable database of parts diagrams.

Sent from my LGLS991 using Tapatalk

What's the proper clearance? NMD: YT video below gives it at 1:44 as Intake at .006" and Exhaust as .008".

ETA: YT search on "How to adjust valves on Honda GC engine" yields this as the first result:

 

[KnurledNut]

Are you releiving pressure on the pump side. Mine pulls hard unless I pull the trigger on the gun to releive pressure.

I just got it, so haven't even hooked the pressure washer hose or gun up to it yet.

Do this before you go any further. Hook everything up.
The mechanicals are most likely fine.

 

[MarlynOC]

Did you pull the spark plug out to see if it is hard to turn over with no pressure in the cylinder?

 

[Old Man Roger]

Did you pull the spark plug out to see if it is hard to turn over with no pressure in the cylinder?

Pssst, read the title, or the first post

 

[LawnBoy-5247]

I could not tell you off the top of my head but the number you got from the video sounds correct.

Sent from my LGLS991 using Tapatalk

 

[bpjr]

I wouldn't buy a cam until the valves are checked.

 

[James-W]

I am not so sure the engine has a pressure release. Since it is a 160 cc engine, that would make it about 5hp and an engine that small shouldn't be that difficult to turn over even at full compression. I could be wrong, it may have a compression release, but I have some doubts on that.

This is confusing to me because if the engine turns over easily without the spark plug, and then turns extremely hard with the spark plug in place, then it isn't the pump causing the problem, it is the engine. But small engines like this don't normally have a great deal of compression where you have a hard time starting them.

 

[FTG-05]

I would try to adjust the valves first before you buy a cam that way you don't buy unneeded parts.

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Well that didn't take long. Watching the YT video above, it took me about 30 minute +/- to get the valve cover off, check the valves and readjust them.

After getting to TDC, I was able to confirm it by the two hash marks on the cam. Exhaust vavle appeared to be OK at .008, didn't see or feel enough difference to change it, so I left it.

The intake valve, however, would not let a .0055 gauge through (.004 plus .0015, closest I had to .006). So I adjusted this to where it would slip through with minimal resistance. Put it all together and - no change.

The insides of the valve cover are really super clean and the timing belt looks brand new, i wish I had taken some pictures. I highly doubt this engine has been run for very long.

And I now have the complete serial number for the engine: GCAH-1244376 QHA. According to the partstree site, this is the cam part number for this engine:

Honda 14320-ZL8-010

PULLEY, CAMSHAFT https://www.partstree.com/parts/honda/parts/14320-zl8-010/

And the cam timing belt:

Honda 14400-ZL8-013

BELT (84HU7 G-200) https://www.partstree.com/parts/honda/parts/14400-zl8-013/

What do I need to look for on the cam to see if the unloader is still attached or not?

Thanks for the help!

 

[FTG-05]

Do this before you go any further. Hook everything up.
The mechanicals are most likely fine.

Sorry if I wasn't clear earlier:

- Hard to turn with spark plug installed

- Easy to turn without the spark plug

I did hook up the gun and pressed the trigger, it had no affect, which I didn't expect it would.

 

[LawnBoy-5247]

The bump on the cam is the compression release. watch the exhaust valve as you turn the engine over you should see the exhaust valve open slightly as the engine reaches top dead center. If it does that the compression release is working.

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[rustbucket5]

so when your checking the valves an overly tight valve would mean potentially less compression(not in this case but if its really tight) where as a loose valve adj would cause the condition your having. did you look at the exh rocker to check its not cracked? and when you were turning the engine did it look like the rockers were fully pushing the valves down? if not it could be a worn cam. some small engines use plastic cams not sure on this one

 

[FTG-05]

The bump on the cam is the compression release. watch the exhaust valve as you turn the engine over you should see the exhaust valve open slightly as the engine reaches top dead center. If it does that the compression release is working.

Sent from my LGLS991 using Tapatalk

Learning something new every time you post, thanks!

 

[FTG-05]

so when your checking the valves an overly tight valve would mean potentially less compression(not in this case but if its really tight) where as a loose valve adj would cause the condition your having. did you look at the exh rocker to check its not cracked? and when you were turning the engine did it look like the rockers were fully pushing the valves down? if not it could be a worn cam. some small engines use plastic cams not sure on this one

Did not notice, but did not look for it either. How far down should the valves move?

Thanks,

 

[bpjr]

My briggs & stratton engines are way sensitive to valve clearance and TDC. There is also a procedure to find TDC and then reverse the piston down 1/4" to set valves. I think this has something to do with the cam bump. I've adjusted valves on many engines and these B&S are the only ones I've seen this done on. Your Honda may have something like this.

 

[Rory Bellows]

Did you take the pump off? That would be my first move. The pump probably could use fresh oil anyway. Maybe the keyway on the pump is jacked up.

 

[mbshop]

Go to the basics of how a 4 stroke engine works. Now work from there. Is the cam opening and closing the valves ? Yes, no. Go from there. Even on my tt500 Yamaha 4 stroke i could turn the engine over.
So again, go back to the basics of how a 4 stroke works.

 

[WittHay]

Not familiar with the Honda GC series, but the commercial GX motors can get locked up quite easy by them tipping over or not turning off the gas.

On the GX motors, we would take out the spark plug and get the oil out of the cylinder, drain the oil from the carb fuel bowl, change the oil and clean the spark plug with starting fluid and it would fire right up, smoke for a bit but worked fine.

 

[FTG-05]

Not familiar with the Honda GC series, but the commercial GX motors can get locked up quite easy by them tipping over or not turning off the gas.

On the GX motors, we would take out the spark plug and get the oil out of the cylinder, drain the oil from the carb fuel bowl, change the oil and clean the spark plug with starting fluid and it would fire right up, smoke for a bit but worked fine.

My wife brought it home in the trunk of her car. Oil spilled onto her trunk pad (which I have to clean today) so the first thing I did was pull the spark plug to eliminate any oil in the cyclinder (if any). There wasn't.

 

[FTG-05]

Did you take the pump off? That would be my first move. The pump probably could use fresh oil anyway. Maybe the keyway on the pump is jacked up.

I saw a YT video yesterday where they said +90% the cause of this problem is a missing or jacked up keyway.

Is the keyway on the pump side or the recoil starter side? It wasn't clear from the video since he had the engine apart.