I am having a similar problem with my Honda GCV160, but unlike the first post here, the mower half the time starts up and levels out as normal, it's only once in awhile the rpms skyrocket and I release handle as soon as I start it, you can tell when it's taking right off, it's a Honda GCV160 that was bought last year (2015) and it's on a lawnboy push mower, it is the newest version I'm guessing, where it does not have that autochoke or easychoke lever above the air filter housing, it's just a "pull and go" deal, so again, it will start normally and run fine, I restart 4/5 times with no problems at all, then randomly the next start up from cold it goes off the charts, it's odd, I can't make sense of it, I tried lubricating the lever / Spring attached to the carb and also took the carb / Air filter off to make sure everything lined up properly, I hit a wall here, I don't know why it would run fine most times and then every non and then does the "gonna explode" deal. Any thoughts, help or ideas would be much appreciated. Thanks.

***"BLACK would indicate oil fouling"*** Not necessarily the exclusive deciding factor. The black color only indicates carbon. The source of the carbon will be revealed by other facets of the carbon deposits. Carbon deposits due to lube oil will have a glossy look and will be quite gummy/sticky when scratched. Also the built up deposits can be quite thick and uniformly cover everything about the spark plug completely. Carbon deposits due to a very rich fuel mixture are sooty and powdery looking, and when scratched, will readily shed dryish flakes or specks. Often, where a rich mix is causing carbon, you might see places on the spark plug where the carbon has already flaked off or areas where the carbon seems not to be as thick. A poor boy's method for testing/guessing at compression issues can be done using compressed air. If using this technique, you will need both valve covers removed. You will need an adapter fitting that threads into the spark plug hole and accepts to being fitted to a shop air hose. The engine must be rolled to the correct position (piston 1/4" down and beyond TDC point of the COMPRESSION stroke) for the cylinder being checked. The engine absolutely MUST BE HELD FROM TURNING by some means to prevent the piston from reacting to the compressed air. You would have to figure out how to hold it with what you have on hand. An alternative method that does not require engine to be "locked" is described at the end of this description, so read carefully not to get the 2 confused. Air pressure needs to be 90 PSI to 120 PSI for best results. The air hose and all fittings need to be free of leaks as you will be "listening for leakage" in the test (and any air leaks in the plumbing can dull your testing accuracy). Each cylinder must be tested individually and the piston for each cylinder must be in the correct point, which means you will have to go through the locking and unlocking of the holding device for each cylinder. Once the engine is rigged against turning, apply compressed air to the cylinder you are testing. Now, you must listen carefully for air leakage. I use a 3 foot length of 3/8" plastic tubing to pin point the leaking spot/area by using it like an impromptu stethoscope. Hold one end of the tubing near to one of your ears (but don't stick it in your ear) and probe the following places on the engine with the other end of the tube: Get inside the valve push rod area of the cylinder head where the head meets the block. If the head gasket is leaking, that is where the leak will be. If you hear air leaking, and it gets louder as you probe nearer to the head/block juncture, and begins to become quieter when the probe goes deeper into the gallery (has moved past the head/block juncture), you have located the leak. But.....if the noise level continues to increase the deeper into the gallery the probe goes.............the leak may be coming from the opposite cylinder head or rings. So you have to test BOTH cylinders the same way, but one at a time. If you find that escaping air noise heard through the plastic tube increases on BOTH cylinders the deeper into the galleries the probe is inserted, and you do not hear an obviously louder sound when the probe tube end is positioned right next to either head/block juncture seam.......... the air is escaping past piston rings. This test method will also identify valve leakage by placing the probe tube into the exhaust/muffler or the intake/carb locations. There is also an alternative to rigging a holding fixture to keep the engine from moving under the influence of the compressed air. The alternative way is to REMOVE the push rods from the rocker arms of the cylinder you are testing and simply place the piston at BOTTOM DEAD CENTER (BDC). With the push rods removed, the terms compression, power, exhaust, and intake stroke become meaningless, as both valves are closed. The push rods must be marked so as to get them back exactly where they came from. It only requires finger tip pressure to push the valve spring down to remove the push rods. My thoughts on the Vanguards having "head gasket issues" are that the "true Vanguards" (and the 303700 is a true Vanguard) do not have any ill repute for head gasket failure. On the other hand, the Briggs single cylinder OHV 280000 and 310000 engines DO HAVE somewhat a reputation for head gasket blow out. Same goes for the Briggs V twin OHV engines that are just based on having one more cylinder of the same design as the 28 and 31 OHV Intek family (405700 and 445700). This post was edited by mownie on Tue, Feb 4, 14 at 12:02

"...It's possible to make a car that does not break. Period..." Really? Even LEXUS owners have problems with their cars! And my old boss bought a new S class Mercedes. (S500) And it was eventually declared a "LEMON" and was replaced. Automobiles are still assembled by humans. And those huumans can have bad days and miss something on the line. It happens. And yes, not too long ago all American automakers built crap. But the quality has improved a great deal. So a Buick that's over 10 years old is not even in the same league as a Buick that's 2 years old as far as engineering goes. As a matter of fact, in 1999 we rented a brand new Park Avenue while on vacation. My wife called it a piece of garbage compared to our '88 Volvo. The power seat controls came off in her hand! Yeah, garbage! But I'll guarantee that the Lucerne is light years ahead of that Park Ave! In both quality and engineering.

Pico - I live in the Rio Grande Valley. In some places it is hundreds of feet deep in the sediment that has eroded off the Rocky Mountains and out of the old calderas - gravel, sand, and clay closer to the river. That trench is in a silt-loaded sand that is common as a top layer in some places. I know from the soil surveys that it's 50-100 feet deep. Houses made of mud brick are common. They also fall apart if you don't keep them dry. What we are short on is organic material. I have almost nothig you could call "loam". What do you think of carpenter's wood shavings? Thin layer of wood shavings in the compost every 4 inches or so? YES!!!!! As much as you can scavenge. My compost is about 1/2 pine or juniper sawdust and half weeds and leaves and kitchen scraps. We use locally made pellet fuel as cat litter - the pellets fall apart into sawdust when they get wet - and the urine-soaked sawdust (minus the feces) goes in the bins, layered with whatever I have available. It makes a coarse compost that doesn't vanish in the dirt as quickly as the finer stuff, which is what I want. "It would be nice if every island had a huge wood chipper, shredder etc. for public to use for a certain fee." Excellent idea: Suggest it to the island government as a way to minimize trash and help the people trying to grow things. Or find several other people who would have a use for it to share the cost.