Stalling....
If your stall occurs when you are at idle, then as soon as you hit the throttle, there's a dead spot. And if you can feather the throttle a little to get past that dead spot and the engine runs fine, it's your accelerator pump.
These are a PITA when it comes to keeping a crisp fuel system. The pump is a small diaphragm pump and is used at take off, to provide a small squirt into the fuel to give the engine it's initial speed up to build manifold pressure (vacuum) to start pulling fuel through your venturi on it's own. If you look at the exploded view, you'll see it inset as
part #63. To check this, take off your air box. It's easier to have help but you can do it yourself. Once the airbox and flame arrestor are off, look into the throat of the carbs. You'll see this small brass nipple (jet) about 1/4" long or so. Now, either have your friend goose the throttle or you can grab your sync bar on the linkage of the carb and wind it to wide open. When you do this, you should see a squirt of fuel shoot out from each of these. With the motor off, you can only do this a couple times before the fuel holding inside the diaphragm runs out. So, make sure you are watching closely when you do it.
There are also a series of check valves, small balls and springs, that help control the operation of this system. You'll notice a brass elbow where those nipples go through the body of the carb. These are also check valves. Take a can of carb cleaner, use that little red plastic tip on the end. Take off the little small hose to each nipple and spray a squirt into each one. You'll see it shoot into the carb once it's clear.
If you get to the point that you have to dis-assemble that accelerator pump, be careful not to rip that diaphragm. The only way to repair it is buy a new one and they cost about $200 bucks..........
Your adjustment on the oil pump. You can only adjust this if you've checked the adjustment on your carbs. They need to be at "0". Which means, back them off your idle stop screw till they are not touching. Turn that screw in two full turns. Then, check the alignment on your oil pump cam.
The problem with that oil on your RAVE's is normal, depending on how often they have been cleaned. Better to have oil than dry and blow the engine from a lack of oil. This is something you also see when premixing the oil verses using the oil pump. Also, the type of oil can play into how much oil or carbon is on them...............but, this is not the cause of your stammer when taking off..........it's def your accelerator pump...........:cheers:
