GX160 No-Start

[Sleepy122CID]

Just picked up a project kart on the low-low with a maybe kinda running (maybe not) GX160. When I went to look at it the guy started it with an electric drill. Today I realized that was because the recoil starter is falling apart (I can't get the screw to hold the assembly to the cover - it keeps backing out every time I pull the rope). When he started it, it would run for maybe 20 seconds or so before dying.

Today I cannot even get it to do that. First I pulled the spark plug and found it was incorrect. Installing the proper plug (properly gapped) did not help. I checked to make sure the spark is consistent, and it seems pretty strong. I remembered the seller telling me he put a new carburetor on it, so I figured I better check that next after seeing the kind of plug that was in it . The float seems to be working properly. As I was pulling it off I realized the idle screw was maxed out. I continued removing it to check it out even though I guess the idle thing could be leaning the mixture too much. When I got the carb off I checked to make sure the intake valve was moving freely, and it appears it is.

Now, although I work on cars for a living, I am a youngster and have never even looked at a carburetor up close . I found a hose barb with nothing on it, and I was wondering what it is if anyone knows. I guess this is a very simple carb, for there are no fuel adjustment screws?

Anyway, what is this exposed barb for? I haven't checked compression yet, so I'm not at a dead end yet with the diagnosis, but if you have any ideas I am open to suggestions... This is the first small engine I've really looked at.

(smaller barb on top)

Thanks

 

[Sleepy122CID]

GX160 is supposed to be a 4 stroke engine, correct? Unless these small engines are supposed to do some weird ish, I've got a problem hah. I pulled the valve cover, intake, and exhaust off, turned the crankshaft by hand, and the exhaust valve begins opening just slightly before the intake valve even finishes closing. Then after the compression stroke the exhaust valve opens fully before the cycle starts again.

Is there something odd I should know about little single cylinder 4 stroke engines or can someone tell me where to find a service manual for this engine so I can set it up properly?

 

[anderkart]

Looks like you need a short fuel hose looped in between the barbed fittings of your pet cocks outlet and the carbs fuel inlet.

The reason your seeing that valve overlap is your engine has a compression release feature that holds the exhaust valve open longer for easier starting. Once the engine is running the valves will open/close normally.

 

[Sleepy122CID]

Looks like you need a short fuel hose looped in between the barbed fittings of your pet cocks outlet and the carbs fuel inlet.

The reason your seeing that valve overlap is your engine has a compression release feature that holds the exhaust valve open longer for easier starting. Once the engine is running the valves will open/close normally.

I'm not sure exactly what petcock you are describing. In the picture, the large right angled barb is the inlet from the fuel tank.

And are you talking about valve overlap when the exhaust valve is supposed to open, or an extra exhaust valve opening? Right now the exhaust valve is opening twice for every one intake valve opening. Sorry if that is what you are describing as the feature...