Stevo here with the Pro V 200. I have had the mechanic run 50:1 through the engine but it takes about 10+ hours of use for the plugs to foul. They are all equally saturated. Mechanic has dialed back the oil injection once - but is hesitant to keep doing so - for ramifications are expensive if modifications are too abrupt. Is the solution the oil pumping system? Mechanic says when it fails, it will pump like mad and save the engine.

I run no ethanol 92 octane gas, Yama Lube, and place ring-free into my gas. I pay - but it does not seem to play...

What is the ideal temp range when at normal operating range? I will get one of those temp guns for testing.

Does anyone think the issue could be related to a weak electrical impulse and hence the plugs fouling. When i am WOT with clean plugs this baby flies!

Steve,I hate to second guess your mechanic,especially since I'm not there looking at your engine.But since I have a 1992 ProV 200(modified),and a highly modified 220 Excell(which I just broke the other day),I'm going to throw my two cents in.If you want to call me an idiot later,get in line behind my wife(LOL).Anyway,I doubt seriously that you ignition is bad.This system is really reliable and believe it or not,is used as a popular modification on Evinrudes used for racing.The spark does not break down at high RPM's like the OMC does(I'm talking about HIGH RPM's).Have you tried pulling a plug and grounding it against the engine and cranking it over?Doing this in the dark will make it easy to see as the spark should be huge.If the spark is weak,check all of the grounds,especially the battery to engine ground(actually at the starter) and the coil to engine grounds(there are two,one at the base of each cylinder head;each set of three coils goes to one ground).An easy test would be to take a peice of wire and go straight from the battery negative and clip it directly to the coil ground and see if it improves.Did you disconnect the oil injection completely?I don't use it because I turn higher RPM's than the injection is designed for.It is a reliable system,but poop happens,and since all of the plugs are fouling,sounds like it may be the key.The way the 200 is set up for fuel pumps,a bad diaphram will only foul the one cylinder that it is picking up it's pulses from.It will run horrible,but the worst case is two plugs fouling if both pumps are bad.
(I run an electric fuel pump because of fuel flow and the use of a primer system instead of choke plates.)Hope some of this helps.

Stevo, stupid question but I have to ask, when the mechanic switch over to premix he disconnected the the oil injection line right? Your problem is a real beaut. We'll keep this one at the top, somebody else has had to have it before and hopefully chimes in.