Vehicle: Pilot
Engine: Stock, 81.5 bore/Wiseco piston
Carburetor: Kein WPK (I think it's a 39mm)
Compression: Apprx 130lbs/sq in (rings are not seated to cylinder yet so I think this is okay)

I just finished a top and bottom rebuild on my Pilot's Engine. Initially it started without issue. I ran it about 15 minutes to bring it up to operating temperature to confirm the cooling fan works before I shut it down. Now it will run for about 1 second, then not fire again. It appears to be getting an excessive amount of fuel. Spark appears strong. I removed the carb and see nothing obviously wrong. It's clean and the float valve stops the flow when the floats are raised. I didn't dismantle the carb until this problem so I don't see how the floats could have gotten out of adjustment. Unfortunately I don't have another carb to install at this time. The spark plug is soaked and raw fuel is coming out the exhaust flange. Maybe the excess fuel is because of the no fire but there is a lot in a short amount of time.

Any help is appreciated,

Diaphragm in fuel pump ruptured and its letting raw gas to be sucked into the crank case?

You sure the pilot jet is installed and tight?

I'm positive it's the carb. A few minutes ago I installed the spark plug while the carb was removed, I hit the starter and much to my surprise, the Engine started with increasing speed until I hit the stop about 3 seconds later. The only source of fuel would have been in the crank case. I wonder if the crankcase has an excessive amount of fuel sitting in the bottom of it, causing a perpetually flooded condition. I might just need to let this fuel evaporate out. I can't explain how this excess fuel would have built up in the crankcase though.

Hey Hoser. Thanks for the help. It's getting good fuel flow. Are you suggesting fuel could be entering the crankcase through the pulse tube?

I checked the jets for debris. They are clean and tight.

Yeah, check to see if their is gas going through the pulse tube

if you pull or pinch the fuel hose going to the carb and its still flooding out then you know its the pump.

it should run a good 30 seconds with a full float bowl and no fuel from tank

I dismantled the fuel pump but did not see anything wrong.
No punctures in the diaphragms.
Before I removed the pump, I tried to start it again without the carb. This time it didn't fire. All the fuel in the crankcase must be gone.

Here are some pictures I took.

look close hold it up to the light it only takes a pin hole..

Also perform the test hare suggested.

Okay, I'm an IDIOT!

Thought I'd try one more thing before I gave up. Went out this morning and bought some new plugs. I didn't think it was the plug because it ran fine initially. I've had something similar happen before. I think we were at Ocala when my Engine quit running for no apparent reason, spark plug looked good with a strong spark so I looked elsewhere for the problem. Change the plug out of desperation and Engine started right up. I waisted a lot of time and effort figuring this one out. At least I got it running. Hopefully I'll remember this lesson.

Hey we all have OOPS's at least you provides us with nice pics of pump tare down. We all have brain farts every once in a while or at least I do.