Where to go from here

[Oberon]

I just recently took my heads off to install some intake valve seals with the hope that this would fix my engine problems,(missing, which I thought may be caused by fouled plugs) I put the heads back on, re adjusted the valves, replaced the plugs, set the timing to 7* btdc, synchronized the carbs to 9, and adjusted the carbs. It starts perfectly, idles fine, but when I rev it a little, it makes a pop pop pop sound that sounds like its coming from somewhere around either #3 or #4. The sound goes away after driving it for awhile but the motor still continues to miss while under a load and seems to get worse as the engine gets hotter. I checked the cylinder compression and each one is about 120 psi. I checked to make sure I had spark on all four plug wires. I rebuilt the carbs last year with a rebuild kit from EI. Also, I pulled the plugs, and turned the motor over a little with the valve covers removed and noticed that the #4 exhaust valve makes a PSSSSS sound every time it opens. I don't know where to go from here. No mechanic in my area will even look at it, and I've hardly been able to drive it since last September. I can't take it to the trail cause I'm afraid it will break down. I do realize that the Pinz isn't going to run perfect, but it's running horribly compared to when I first bought it.
PLEASE HELP
Spence

[milesdzyn]

When re-adjusting the valves, are you sure you got the correct TDC for each cylinder. There are 2 TDC, one for compression with both valves closed and one for expulsion where just the exaust valve is open.

Miles