The valve adjustment process on the GCV160 is via lock-nut and screw adjuster, except the "screw" requires Honda special tool 07708-0030400. The cover is not disposable, but is easy to bend if it is not removed carefully. The clearances, checked with a cold engine, should be:
intake: 0.15 mm
exhaust: 0.20 mm
When replacing the cylinder head cover, Honda recommends Three Bond 1207, Honda Bond #4 or equivalent sealant (which is why the cover is difficult to remove.)

You can buy a manual online from Helm, Inc. It's $33.95 with shipping.

Calling it timing isn't really the right word. If the Honda onwers manual says that, chaulk it up to poor translation between the japanese engineers and american writer. Both of whom are pencil headed nerds who only know what is in print.

Valve clearance would certainly be better.

The cover is flimsey and easily distorted beyond use. You may want to ask for the cover for the GSV-190 engine which is a commercial grade version of the GCV. It uses a cast aluminum cover.

As far as I'm concerned if the engine runs good and there is no valve tapping I wouldn't adhere to the 150 hr intervals, maybe double that. We've had engines in the shop with as much as 500 plus hours that have never had the valves adjusted and still don't need it. If plug is burning clean, starts easy and run right, it ain't broke.

I have an older, from the late 80's, Honda. It smokes a little at start up. Will a valve adjustment help this?

Nope. The start up smoke is fairly common.
Sometimes, loosening the dipstick after shutting off the engine and allowing the crankcase to vent helps. Leave open 20-30 minutes.
Sometimes it seems like a change in oil viscosity makes a difference.
After all that, sometimes it'll smoke again.
In any case, a couple seconds worth of smoke isn't anything to worry about. My 89 has been doing it for more than 10 years.

That's very useful. Thanks for the replies.

Valve timing is probably an expression used more in Europe (I'm a Brit living in France) & is certainly a phrase used in car & motorcycle engine circles over here. I agree with you that valve clearance is a far better phrase to use.

Anyway, that's brilliant. Thank you.

Cheers, Dommmo.

Dommo, thanks for the terminology explanation. Guess I should retract what i said about those nerdy manual writers. I do know they try to write for world wide markets and this would explain it. Does make it confusing for Americans though who think of valve timing as a cam timing function.

Vertical shaft OHV engines do often have a bit of smoke at start up. The channel which the belt on OHC or push rods on regular OHV's are located are also just above the sump oil level. Not to mention the cylinder bore itself. Very much in the way of over filling or just minor forward tipping will put excess oil in areas that can cause it. Just moving the mower around pre starting can do it. As long as the smoke is just a few seconds at start up, it really is nothing to worry about.

All Honda engines are run at the factory and drained. However some residue remains. As a result, shipping, storage and even our display racks which face front of engine down means almost all of them smoke a bit brand new when servicing them at point of sale. Just the nature of the beast.

Dommo, sorry about the mini hijack.

Bill, Walrus, the smaoke only last a few seconds. The way it's stored in my gargae, I do move it around a lot before I start it, and I often have to tip it to clear the other things in my way. Thanks for the info.

My mower with the Honda GCV 160 was purchased in 2000, ande now has over 400 hours on it. This is the first I have heard about adjusting the valve clearance. I do not recall anything about this in the manual. I would seem to be prohibitively expensive if you had a shop do it, and how many home owners would ever attempt it?

That valve cover is hard to remove. I tried it a couple of years ago, just to see what the overhead cam layout looked like, and gave up on it as it was obvious that I was going to bend it.

Valve clearance and valve timing. If the Europeans call valve clearance valve timing, I wonder what they call valve timing, i.e., the point at which the cam opens and closes the valve?

'Sometimes it seems like a change in oil viscosity makes a difference.'
Honda allows the use of SAE 30HD when the oil is not below 50 degrees F at start-up. This would perhaps solve the slight oil smoke on start-up, although I would rather see 10W-30 for this OHC/OHV engine. I had one for a couple years and it did that once in awhile on 30W. Most every 4-cycle I've ever had did it sometimes, but it seems it was more often than not on the Honda. Probably has to do with the architecture of the block where the bottom of the cylinder is in oil with the engine at rest (maybe).

"Probably has to do with the architecture of the block where the bottom of the cylinder is in oil with the engine at rest (maybe)."

Now that I think about it, I don't recall it smoking the 2 times I started it this Spring. The oil is about 1/8" below the full mark,where typically, it's at the mark or maybe slightly above. Maybe that's the solution???
The smoke has never bothered me (after the first couple times). I just figured I'm getting a little extra upper cylinder lube at a good time for it. Consider it a "feature". :-)

I have a 4yr old mower.
It has good spark and compression.It trys to start but doesn't. I checked the valves to make sure they were opening and closing. It sounds like the crank is out of time with the cam. Is it common for the belt to jump time.
How do you time the crank to the cam. Are there timong marks etc. I hate to throw it away

Make sure the fuel valve is open. If that doesn't do it, clean the carb. Parts 11 & 23.

On the bottom of the cam, there are two lines that should
line up with the edge of the valve cover sealing area, and the keyway on the crank is perfectly perpendicular with that line, that is how you check the belt timing.

Fish

Thanks Fish,

Can you please tell me what part of crank is called keyway?. If possible can you please sketch something really quick for it.

Thanks a ton.
Pradeep

I have a new excel power sprayer with the Honda engine noted. Every time I get it started it runs for about 3 minutes and then dies. I change the plug but it still does the same thing. Is there something I'm missing? Could it be bad fuel? A few times it continued to run until I activated the sprayer unit. Any info would help.

does anyone know the specs. for valve clarance on honda gxv140? i just got this mower used it smokes and has a ticking noise from the valve area. hope ajusting the valves will fix both problems.

I'm having the same problem as a previous poster, except that mine is a Karcher power sprayer and the engine is a Honda GCV 190, and could not find an answer on this forum. Here was the issue: "RE: Honda GCV 160 E Engine Question Posted by bono (My Page) on Sun, Aug 10, 08 at 18:47
I have a new excel power sprayer with the Honda engine noted. Every time I get it started it runs for about 3 minutes and then dies. I change the plug but it still does the same thing. Is there something I'm missing? Could it be bad fuel? A few times it continued to run until I activated the sprayer unit. Any info would help."

This thread is a hijacker's picnic! Dudes! Start new threads for these questions not associated with the original question.

Can someone please tell me what would be a good birthday gift for my great aunt Sally?

MY 2.3 YEAR OLD HONDA LAWN MOWER WITH THE ABOVE ENGINE VERSION HAS STARTED SMOKING BIG TIME.SO BAD THE SPARK PLUG OILS UP AND THE ENGINE CUTS OUT.

ANY COMMENTS PLEASE

REGARDS
MARK

Can someone please tell me what would be a good birthday gift for my great aunt Sally?
-----
What every great aunt wishes for...a set of feeler gauges to check mower engine valve clearances.

I want to check the valve clearances. What position does the engine need to be to check intake and exhaust on a GCV 160 5.5 HP OHC.

Check the clearances at TDC, both valves closed. There are also two hash marks cast into the bottom of the cam gear that are visable just over the edge of the block to confirm that you are on the right stroke if you wish.

I have a gcv160 honda pressure washer that I bought at an auction. I know nothing of it's history and when I got it home and started messing with it I found out it has no compression. I checked this by taking spark plug out and putting my thumb in plug hole and pulling rope. No compression. I'm good with older engines but no nothing of the Honda. How do I check to see if valves are stuck?

"How do I check to see if valves are stuck?" If there is absolutely no compression, my guess is the valve cover comes off. Be gentle, as they have a tendancy to bend. Then you can work some gumout in around the valves and hopefully free and lube them up.

My GCV 160 mower will not start without moving the belt around underneath the deck. At times when I move the belt the mower cranks. What do I mean about moving the belt?
The belt is loose so I squeeze it etc, I never turn it. Once I do this it cranks. I have to do this before it cranks when its cold.

What happend to my post?

You left your post next to the garage door as you walked out this morning.... Or you could try this one.

Here is a link that might be useful: another GCV post