First, some clarification. The decompression system uses an extra cam lobe, right behind the timing gear on the camshaft, adjacent to the exhaust lobe. The mechanism is centrifugally operated. If you crank the engine with the rocker cover removed, you should be able to see the rocker arm "bump" during the compression stroke, long after it has opened and closed the valve fully during the exhaust stroke. I suggest you watch the valve movements. If the "bump" is clearly happening, all is well. If it isn't, the probable cause is too much tappet clearance.
The compression pressure you have measured, 130 psi, is only slightly below the 140 or so I would expect as the nominal reading for an 8:1 compression ratio, and normally a range of plus or minus 20 to 30 psi could be accepted. Hence there does not appear to be any major level of leakage through gasket, or past rings or valves. Hence I cannot sustain my initial suggestion that you had a problem in that area. I was overly sensitive to the bad reputation your engine has rather than waiting for the evidence.
Given that you do not seem to have an exceptional level of blow-by, the cold start and idle quality erratic running issues you have reported are probably due to a combination of two causes: an emissions carburetor, which intentionally runs as lean as possible, and some gum formation inside the carburetor making it substantially leaner even than that. Cleaning out the carburetor with carburetor cleaner will probably make it noticeably better with regard to easy starting and smooth idling. I tolerated having to wait about one minute after cold start with an emissions Honda I have before it would run perfectly without choke for several months once. Then I cleaned the main jet. It now runs perfectly without choke the moment it starts. Emissions carburetors tend to be blamed unfairly at times.
This leaves you with only the oil spray from the fuel pump. There is a thriving industry selling replacement pulse-type fuel pumps for Intek engines, which suggests that your pump may be defective rather than the base engine having a significant problem. If you search "briggs fuel pump" on ebay, you will see plenty of alternatives, many of them genuine Briggs parts.
Because we now have no evidence to suggest a base engine malfunction, the simplest and cheapest way to proceed seems to be to clean out the carburetor, and replace the fuel pump with another pulse type unit. If you are near a Briggs dealer, I suggest you consult him about the fuel pump though, since he will have experience with how long they last and how easy it is to substitute the electric one from the new Intek engines. A new genuine Briggs pulse pump will cost you about $35 including shipping on ebay, so replacing it occasionally is not a huge expense.
Last edited by grumpy; 18/01/13 01:22 PM. Reason: Correction of which valve has decompressor
