I am experiencing an intermittent but instant RPM and power loss condition. It is a '99 Johnson 200 HP, V6, carburated engine. The engine will run great and then an instant RPM drop/ power loss occurs. The motor does not run rough or sputter, just lower power. It sometimes will instantly come back to full power in a short period. Initially I suspected bad-water in fuel and added STP Water Remover and it seemed to do the trick. It started happening again and the water remover quit working long term as a remedy. I replaced the water seperator filter and inspected the contenets of the old one. The gas was uniform in apperance w/ no water apparent in the bottom. (maybe the 'Water Remover' diffused the H2O moleculary like it was supposed to do?) There was a small amount of pinkish slime accumulated on the bottom circumfrence of the filter though.? I have recently replaced the spark plugs and meticuously cleaned all of the spark plug and coil wire connections. I found some considerable corrosion on a couple of these connections and hoped that I may have corrected a high resistance connection to be the problem. For the little test runs that I have taken since, it runs much smoother but the problem started happening again. The frequency has diminished though. Sometimes I shut the motor off and it goes away. Sometimes not. Yesterday, I jammed the throttle up and down and it made the motor go back to full power and it stayed that way for the rest of the time. ??? The old spark plugs were inspected by a mechanic who agreed they looked fine. I did not remove and clean the coil connections though. I have been buying my fuel from one source for the most part because of a friendship. He says his gas is clean. Another friend has found a considerable amount of rusty water in the bottom of his small/removable tanks and is convinced it came from the same source. <br />Based on the above, can anyone help me further? <br />Advise for everyone!!! The level of corrosion that I discovered on the ignition system wireing connections was very concerning! Everyone should take the time to go through their connections! I dont think a 'paid for' mechanic would do the level of cleaning detail that this chore actually requires. Even if it didnt solve my problem I know it was a much needed action for the long run.<br />Help anyone! <br />________________________________________________<br />I thoroughly cleaned the coil/aluminum block grounding contacts last sunday. I'll tell you what, all that I have done has made the engine run smoother and more powerfull than before, but the problem still occurs darn it. New discovery; By radically pumping the throttle, I was able to bring back the full power operation. This worked every time I tried it, about 4-5 times. I'm certainly not satisfied with this but it is an interesting new discovery. I do think I am only losing one of the six cylinders when the problem occurs. Now that I am able to force it back to life with an aggressive change in the fuel delivery, I almost wanna think I am forcing a small chunk of something through a carburetor jet, or something like that. But why does it keep happening? Is it time to have a buster chase my ghost? Man that just scares me! <br />Can anyone help me??<br />Thank you in advance!
. But replacing these items allowed me to learn a little about my motor and 40 bucks will only get you 1/2 an hour at the ghostbusters!