OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Honda Engines GVC 160 intake valve stuck in closed position

I have a Honda lawnmower with a GVC 160 engine. Was mowing last night - was hard starting but got it going. Had to stop to move items and it wouldn't restart. After checking spark, fuel etc. I researched online. Pulled valve cover off this morning and the intake valve is stuck in the fully depressed (in) position. I can clamp a vice grip on the head of the stem that is sticking out, but can not budge it to pull it back out. Sprayed WD40 on stem that shows in the intake port didn't help. Put a little heat from a propane torch on the stem, but the flame kept going out so i couldn't get much heat on it, and wasn't confident that it was a good idea so stopped work and found this forum. Is there a stem puller i can buy, or is there a way to free this without taking the engine completely apart? I can see the valve springs pull the stem out when working, but what pushes it in and could that be broken?

First is not closed but is stuck open.

Sorry I highly recommend pulling the head. It may a valve seat that came loose or the could be just a carbon build up either you remove the valve from the inside instead of try to force it back closed. You will do more damage than good trying to force it closed.

I was able to free the valve stem using Kroil penetrating oil (PB Blast would probably work well too) a vice grip plier and a heavy flat blade screwdriver and hammer. Sprayed the end and also in the intake port, let it sit for an hour. Then clamped the vice grip over the machined head of the valve stem, inserted the screwdriver between the nose of the vice grips and the aluminum housing, put prying pressure on the screwdriver to keep it in place then tapped the end of the screwdriver with the hammer to apply more prying force in a straight backwards direction without bending the stem. The stem backed out of the hole but was still tight. Sprayed it as before then tapped it back into the hole with the hammer. Sprayed it again, reattached the vice grips and repeated the prying with the screwdriver and hammer spraying each time I got to the end of the movement. It eventually became very easy to move especially when I twisted the stem in a circular motion (spun it in the hole). Scraped the old gasket material and used steel wool to get the last bits free then sprayed everything from top down with carb cleaner to flush all dirt and steel wool particles out. Reattached spring and spring plate and rocker arm and had helper pull starter rope while I watched the valves move. Put new high temp gasket Silicone and reattached the valve plate cover. Cleaned the carb and gaskets and reintalled. If you tackle this make sure you know how all of the gaskets go as you take the carb off. I now have to wait 24 hours for the gasket to cure. If anyone sees anything I did wrong please let me know before i add oil and gas and try to start it up. If no comments I will add post to let you know if it worked

Hi KSLJSL, and welcome to the forum.
It sounds like your method worked and the big test will come when you start it. Let's see how it behaves when it gets hot, and update us with the outcome.
Cheers, Ted

OK - put oil in it and gave 5 or 6 pulls without pressing the dead man lever as I wanted it to distribute oil first. Probably not necessary but better safe! poured some gas in and it started on the first pull! It seems to have higher RPMs. Wife noticed it also. Not sure if it sounds higher because it has been running slower due to gummed up valves for a long time or if I messed up settings somehow. I noticed that the rocker arms had a threaded screw that could adjust the throw of the valve stem, but I didn't mess with it. Could it have changed just from dis-assembly/re-assembly? I don't want to burn up my mower from over revving.

Any experts out there that can put my mind to rest or confirm my paranoia?

The GCV 160 does not have any adjustment on throttle speed, so you need to check the governor spring and make sure it's not bound or twisted up and over-pulling the governor arm. If it's still over revving, then you may have an air leak in or around the carby causing it to run lean and over rev. If all is in order and you can't find a logical explanation for the over revving then you may need to stretch the governor spring a "LITTLE" so it's not pulling on the governor arm as much.
A few pics in and around the carby and governor area may help us identify any issues.
A "how to" for posting pictures can be found HERE

OK - bought all new carb gaskets to make sure - only a few bucks so worth it to eliminate possibilities. First picture shows intake port

2ND picture shows governer linkage

3rd picture shows carb about to bolt up to intake port

4th picture shows top of carb and throttle as I go to bolt up. I did notice afterwards that the crank case vent tube was over the governer cable and re routed

The 5th picture shows the governer arm

When I start it up it is very high rpm - no governing at all. The governer linkage doesn't seem to move. I pushed a screwdriver to move the throttle and it doesn't affect RPMS at all. Did I put the carb on wrong or does it just run better with the intake valve cleaned? Again I dont want to over heat or damage engine