Proper way to use muffs

[Fordiesel69]

I think this is it.

-Outdrive down.
-Water hose on either side.
-Water turned on BEFORE starting.
-Do not raise engine above 1k.
-Do not operate gear box????????????????

Is this right?

 

[Bart Sr.]

Re: Proper way to use muffs

The muffs I have only flow on one side and I have heard on here that SOME outdrives or outboards only pickup on one side.

Someone will correct me if I am wrong.

I would add to keep watch over the muffs in case they fall off.

 

[jacknbella]

Re: Proper way to use muffs

I ran my I/O for about 10 minutes yesterday with muffs on both sides of the lower unit and even put it into gear for about 10 seconds (I was circulating Sta-Bil before winterizing). It was cool seeing all the river water come out...YIKES! Anywho, it's perfectly safe to run a water-cooled engine using muffs, although, I do recommend a pair which allows water intake on both sides to ensure maximum water pick-up. But yes, your plan seems to be OK.

 

[bigskiohio]

Re: Proper way to use muffs

do not run to long on just the water with engine not running , i did that and filled my cylinders with water as there was no exhaust pressre to keep water out. apperently i have a bad gasket but not enough to worry about if motor is running.mercruiser bulletin says the same about the pressure.

 

[northernmerc]

Re: Proper way to use muffs

Thanks for the tip. I never thought about that.

Maybe your muffs seal better than mine. Water leaks between the leg and the muffs, which would help reduce the pressure.

 

[jacknbella]

Re: Proper way to use muffs

That's another good point...don't turn-on the water faucet until you're ready to fire the engine so have a buddy (or boat's admiral) help out. Do the same when turning it off.

Keep an eye on the temp guage too just to be sure the muffs didn't fall off or have someone make sure they are attached properly after you fire the engine. If you see a bunch of water leaking out of the muffs with the engine running, you may have a problem with the water pump. I had a little water coming out the sides before firing the engine but once it was ignited, every spare drop of water was being sucked into the engine, meaning, my water pump was doing its job...WHEW!

All in all, it's a fun thing to do because it will wake your neighbors and bring them out wanting to listen to your "baby" purr!!!

 

[Tacklewasher]

Re: Proper way to use muffs

Don't forget to take them off when you launch your boat.

Couple of stories here where people ran in the lake with the muffs on.

 

[mphy98]

Re: Proper way to use muffs

The proper way to use muff...... oh wait that is a different forum I think.

 

[bigskiohio]

Re: Proper way to use muffs

run at water at half open not fully open ,mine always shoots some water out of muffs,

 

[QC]

Re: Proper way to use muffs

Don't agree ^^^^ You want full flow. You don't want to cavitate the pump, that's why you keep the RPM down . . . Max pressure on the drive is going to be the max pressure to seal the muff ears on the lower unit. Not much

 

[redfury]

Re: Proper way to use muffs

I use a shut off valve on the end of my garden hose, that way I can turn on the water right before I start the motor, and shut it off right after I turn the motor off. It's just so much easier if you have to deal with the end of any garden hose if you can shut the water off right there, instead of having to run all the way to the faucet. It also helps when you want to change ends, like a sprinkler head or a adjustable spray gun.

 

[FishinInMizzou]

Re: Proper way to use muffs

AND once it is running, make sure that water is coming out of the pee hole, or whever it is supposed to exit. I had the muffs on mine, turned on and started the motor. My wife noticed no water was coming out of the pee hole. I shut it down and checked - mud dobbers (spelling?) had plugged the hole. It took a straight pin and several minutes to get it cleared so water would flow. Lucky she noticed - I was on board and wouldn't have until I got off of the boat.

 

[RICHARD5]

Re: Proper way to use muffs

No one has addressed the safety of removing the prop or having someone stand watch at the business end.

A couple weeks ago I saw a guy put the muffs on his boat after he hauled out at the ramp. He bent down to check the hose fitting just as his son put the drive into gear. He almost bought it. Instead, all that happened was he jumped up in surprise and bumped his head on the swim platform and then fell back against a palm tree (the kind with the sharp fronds on the tree trunk). A few punctures to a sore back sure beats a laceration to the forehead or arm.