running outboard on muffs - 1st timer

[jhafner]

Hi,

I've had my boat for 2 summers now and am wondering the proper way to run a Johnny 115hp on muffs. Typically, in the spring I would just head to a local lake and spend 15 minutes trying to get it started for the first time. This year, I would like to run the motor in the driveway. I know you need to run constant water from a garden hose to the muffs. But honestly, I am very nervous about the proper way and prevent overheating or worse. Thanks in advance.

J Hafner

 

[tashasdaddy]

Re: running outboard on muffs - 1st timer

very simple, put the muffs on turn on the water wide open, the muffs are going to leak, as the motor will not take all the water. it can run for the next year like that. do not rev above 1500 rpms, or you could do damage, run away motor, because there is not load on the motor.

 

[lifeisfun]

Re: running outboard on muffs - 1st timer

Just out of curiosity ... , I have F60 2006 Yamaha,
is it OK to connect the garden hose to the flushing attachment
that is on the top of the outboard and start the motor for 2-3 minutes ?
Just for testing.

 

[Captain Paul]

Re: running outboard on muffs - 1st timer

Your owners manual may say "do nut run on the flush hose" or somthing similar. I flush with the flusher and run it on the muffs. I like the style that feeds both sides of the lower unit with water.

 

[lifeisfun]

Re: running outboard on muffs - 1st timer

Hmmm...

I spoke with a guy named Mark at Yamaha Corp. in Atlanta, GA and here is what he says is the official answer about how to properly flush a Yamaha engine.
If the engine has a flush adapter and your water source has enough pressure to cause a stream of water to discharge from the cowling drain (pee hole), then it is fine to run the engine on the flush adapter only, but it's limited to 1500 RPM max and no longer than 15 minutes. This also ensures adequate water for water pump lubrication.

If the overheat horn sounds or you cannot get enough pressure for water to flow from the cowling drain hole, you are required to use BOTH the flush adapter and a lower unit flush adapter simultaneously. Additionally, you should never start the engine out of the water until you have allowed adequate time for the engine block and lower unit to fill with water and start draining out. If water is draining out of the lower unit, it is in fact lubricating the water pump.

Please don't assume that I'm trying to tell you how to maintain your engine, just merely trying to alleviate all the ambiguity surrounding this issue. I shared with him that their technical data (Owners Manual) is inconsistent, but he had no response. I hope this helps

 

[andymach23]

Re: running outboard on muffs - 1st timer

I keep my boat on a salt water pontoon berth. As an experiment I connected my muffs on the leg then submerged the engine again. With the hose running and the engine started, the tell tale water stayed fresh and not salty. I was thinking that the water pressure from the hose was keeping the salt out.

I did this as I was worried about salt build up using the upper flushing port as the thermostats weren't open.

Thanks

Andy

 

[Captain Paul]

Re: running outboard on muffs - 1st timer

Nice to hear it from a Yamaha employee. I think my manual says not to run it on the flush hose. While on the flush it does have enough pressure to run out the tell tale. Even though I run lake water only, I usually flush when I get home.
Somehow that last line just does not sound right.