Sully
When the oil pump failed recently I had just over 1000 hrs, I had an alarm indication, so since the alarm worked I did not damage the engine.
The injector driver failed just after having the new oil pump installed, so it is very possible that the mechanic did something terribly wrong, BUT when I took the engine to a master mechanic to diagnose the injector driver failure he felt as though that the injector just happen to fail and most likely wasn't related to the oil pump repair. The symptoms of the injector driver failure are that the engine runs rough and shifts rough and will only reach 2000 rpm. A new injector driver is well over $1000 a used one is $300-$500.
My lower unit fluid had a very slight amount of milkiness to it last year, I changed the fluid and checked it again after about 10 hrs, the milky look returned and I know I had new plug O-rings and they were tight. a simple pressure test is performed and they determine which seal is leaking and replace the seals. I believe the suspects are the shift shaft or the drive shaft, good time to do the water pump impeller.
I have had several mechanics over the years tell me that the ring guard fuel additive is very important. I use it nearly all the time.
NEVER let anyone but a certified Yamaha Master mechanic touch your engine, even for what may seem like a simple repair,
Shop rates are usually about the same all over $90-100, so only use a shop that spends the money to hire master mechanics or sends them to Yamaha school. Even if you have to tow the boat 50 miles, find the right mechanic.
There is a process to clean out corrosion in the outboard motor cooling system, you may want to ask around about it. They recirculate rydlyme through the engine cooling system for several hours. I had a low speed overheating problem on my HPDI a few years back and the process was used on my engine and it worked well. I would check with a Yamaha shop and make sure its okay to do it or how to do it properly. I plan to do it to my Volvo 200 41 B in the spring.
http://www.rydlymemarine.com/.
Here are the Rydlyme instructions for outboards
http://www.rydlymemarine.com/assets/1/7 ... ctions.pdf
I have used salt away on my Volvo but it doesn't really seem to do much for heavier deposits, it may remove salt somewhat, but not much scale.
If you used salt away on your outboard on a regular basis it would probably be a good thing, but its expensive.
I had an issue with my VST a few years back as well but I do not remember what it was.
If your ever in Mattapoisett look me up. May-Nov.