I have twin F115 4 strokes on my '02 Voyager and wondering which is best for these engines to clean cooling water passages following ops in salt water; Option 1) Flushing using the engine equipped device (garden hose to fitting on bottom of cowling), OR Option 2) flushing using a flushing attachment (dog ears) with engine running. Owner manual hgihlights both methods but does not discriminate. Sage advice greatly appreciated! :huh
Which is best method to flush engines?
- Thread starter bbtopcat1
- Start date
Flushing with the flush port is to be done with the motor NOT running.
Flushing with the muffs is usually done with the motor running. I suppose that muffs plus running motor is better than not running but the bottom line is that any flushing is better than none at all. I flush after each trip using the flush port and my 10 year old motor is quite clean in the water passages.
Flushing with the muffs is usually done with the motor running. I suppose that muffs plus running motor is better than not running but the bottom line is that any flushing is better than none at all. I flush after each trip using the flush port and my 10 year old motor is quite clean in the water passages.
If the water pressure is sufficient, the flush port will get to the same places as the muffs. The flow will not be as powerful though but as I mentioned, there is no salt buildup visible in my t-stat water jackets based on inspection. I only use the flush port as mentioned during the normal season. I use a saltaway product before winter layup. The desalting is done with muffs and the motor warm and running.Curmudgeon said:
The key here is to flush after every outing if at all possible.
If the water pressure is sufficient, the flush port will get to the same places as the muffs.
:uhm Only if the thermostasts are open ...
:uhm Only if the thermostasts are open ...
This is a common misconception. Even with t-stats closed. water flows to all chambers, just not as much. It has too. If there were no water with the t-stats closed, the temperatures would rise to high levels without the t-stats seeing those temps or the thermo switches either for that mater. Air is a poor conductor of heat.Curmudgeon said:
Without water flow, the vapor turns to steam. The sensors and t-stats take a lot longer to react and are being heated not by the hot coolant but by heat conducted through the motor's internals(mostly metal parts). This is not a good situation.
I want my passages to receive the maximum amount of water available, and that's not thru a flushing port with thermostats closed. How much is enough? Don't know, how high is 'high'? :wink:
The manual (page 50) for my F250 says to flush via the flush fitting for 15 minutes right after engine operation in salt water.
I may be lucky in that my dock has very good water pressure. When I flush with the port, the pee stream is a strong as it is when the motor is running. Water is shooting out of the LU vents and prop. Is it enough? I guess so since it's ten years without buildup.Curmudgeon said:
I probably flush for 5 to 10 minutes. I would rather stop flushing before the motor is completely cooled down so that when I stop flushing and the water drains out, the semi-warm motor will speedup drying of residual water. Does that help? I really don't know but it helps in my mind
GulfSea said:
That is also what i am doing EVERY time i use my boats. Knock on wood, no problems or build up so far.
FWIW, i do flush for 15 minutes or more per engine.
I know that everyone can't do this but after every offshore trip I take mine to the lake and back her into the water and run the engine until it comes up to normal operating temperature and I also take this opportunity to flush out my livewell system as well. This also washes all the salt out of the the trailer and brakes. 8)
enfish
Well-Known Member
- Joined
- Oct 17, 2006
- Messages
- 433
- Reaction score
- 68
- Points
- 28
- Location
- San Marcos, CA
- Model
- Adventure
seasick said:I may be lucky in that my dock has very good water pressure. When I flush with the port, the pee stream is a strong as it is when the motor is running. Water is shooting out of the LU vents and prop. Is it enough? I guess so since it's ten years without buildup.Curmudgeon said:
I probably flush for 5 to 10 minutes. I would rather stop flushing before the motor is completely cooled down so that when I stop flushing and the water drains out, the semi-warm motor will speedup drying of residual water. Does that help? I really don't know but it helps in my mind
Same here when flushing. Pee stream is strong motor on or off. But, I also run the motor with the hose hooked up to the flush port. Been doing it for 12 years and and have not had an issue... others' results may vary. Water pump impeller gets changed out every 2 years and always looks good, so I don't think it's causing much of an issue. There might not be as much water in the water pump when on the hose, but water does pour out of the water intakes on the lower unit, so I know there is some water...
enfish
Well-Known Member
- Joined
- Oct 17, 2006
- Messages
- 433
- Reaction score
- 68
- Points
- 28
- Location
- San Marcos, CA
- Model
- Adventure
JUMPNJACK said:
Ha! No chance of doing that out here. Most all the lakes won't let a wet boat anywhere near them because of quagga mussel problems.
Anyone have the Superflush system? I have older 2 stroke yamahas that like to overheat when using the muffs even after changing water pump impeller and looking for a way to flush.
NikM820
Well-Known Member
- Joined
- Sep 27, 2010
- Messages
- 158
- Reaction score
- 5
- Points
- 18
- Location
- Daytona Bch Florida
- Model
- Marlin
seasick said:
This is true. Got it straight from Yamaha after being told one day to run off the hose and the next to not run off the hose. Apparently the hose was originally designed for boats left in the water with their motors trimmed up. They also said to run the motors, originally. After a few burnt up impellers they changed the flush procedure and advised to not run the motors. At low rpm the impeller is fine on the garden hose but there is a rpm that could damage the impeller. To keep people from doing this they decided it was easier to just say to not run the engine, but if you ask them about it, they will say it is ok to, just keep the rpms <800 or so. The 15 minutes on the garden hose is sufficient to effectively flush the motor. The 15 minutes is necessary because like he said, it's not a lot of water that flows through the closed thermostat but 15 minutes is plenty of time to get the job done. At the end of the day it's all about what helps you sleep at night. These engines are big investments and you want to feel like you're doing everything you can to maintain them. Old school guys feel better running the motors, they feel it does a better job at flushing the engine. I myself had a hard time believing in not running the motors during the flush, but have been doing it since 2006 and have not had a problem yet. Seasick says he has for 10 years, sounds like it's effective to me.
NikM820 said:
Thanks for that rundown. And it makes perfect sense; I wish Yamaha would put that in the manual so we could understand how this flushing business got to where it is today with all the confusion.
Has anyone made an adapter and used there cockpit shower to flush the motor? As a guy who keeps his boat on a mooring in saltwater, I'll be attempting this set up this summer. Enough pressure you think?
pbaygrady said:
I tried something like that on my cousin's Wellcraft and DID NOT work. I guess it wasn't enough pressure.