Running on Muffs.

[AZBoatDreamer]

Second season of being a boat owner. While running my boat on Muffs do I lower the outdrive down some or all the way down just above the pavement. I have been running it down just enough to see the water flow from under the outdrive. Is this the correct procedure? Thanks.

David

 

[superpop]

Re: Running on Muffs.

I always lower my bow a bit so I can lower my drive all the way down. I figure it is easier on the u joints and gimbal bearing. I never run my motor with the drive up though.

 

[AZBoatDreamer]

Re: Running on Muffs.

That sounds like good practice. Thanks for the Reply.

 

[Fireman431]

Re: Running on Muffs.

Basically in the same position as you would be in the water. I always (personally) thought that the closest to vertical the better, so just off of the pavement.

 

[smallboatlover]

Re: Running on Muffs.

i was wonder something about that i have a outboard but can i run it in gear with the muffs on? like forward and reverse? never tried it was just wonder?

 

[heyyou325]

Re: Running on Muffs.

They, whoever that is, say to never run the motor in gear. I have several times, at an idle. It doesn't put enough water in to run it very fast. Also, make sure it is coming out the little hole it's supposed to come out on the water. It doesn't take long to overheat the engine. And yes, run it outdrive down as you would in the lake. You need to water to pump to cool the engine and not ruin the impeller.

 

[JimS123]

Re: Running on Muffs.

Always run in neutral only.

 

[AZBoatDreamer]

Re: Running on Muffs.

I say I have been running it half way down and make sure the water is flowing from the bottom. I keep an eye on the temp gauge and run it just long enough to reach operating temp. I do this before heading to the lake. I will take the advise to run it on muffs with the drive all the way down just above the Payment.

Thank you.

 

[Ace52]

Re: Running on Muffs.

Not to thread jack but i took my boat out today and started it up for the first time since last season and i was running on muffs i let it run for about 15-20 minutes and all of a sudden my temp gauge went from very low to way high which led to the loud beep noise my boat makes when its running hot.

so im curious to how long you run on muff and if the hose is enough water to run as long as i did.

now im kinda afraid to take it out on the water lol....

 

[AZBoatDreamer]

Re: Running on Muffs.

I run my boat just long enough maybe 5 minutes to reach Operating Temp, and I check Oil Pressure, and Voltage Gages. I have the hose full pressure and make sure the muffs are covering the Inlets completely.

 

[Fireman431]

Re: Running on Muffs.

I have run on muffs for 15-20 min while working or trouble shooting. If the hose is on 3/4, you should be getting more than enough water for it to stay in the temp range. I have never had one overheat on muffs.

You can put it in & out of gear without trouble, but not more than idle. It's not great practice because there is no load on the engine. Besides, it's dangerous. Can you imagine how terrible you would feel if a kid or pet walked into that spinning prop?

 

[heyyou325]

Re: Running on Muffs.

I've also done 20 to 30 minutes while working on the motor, but as fireman said, and so did I earlier, keep it at an idle. I only go in and out of gear to make sure the shifter is working right in the spring.

 

[H20Rat]

Re: Running on Muffs.

Always run in neutral only.

why?

 

[heyyou325]

Re: Running on Muffs.

supposedly under no load the engine can take off, even at an idle. I have never had this happen to me, but you can read this in most any repair manual. There may be other reasons too. My threads above have all said I do it, but only at an idle, and not often.

 

[444]

Re: Running on Muffs.

i was wonder something about that i have a outboard but can i run it in gear with the muffs on? like forward and reverse? never tried it was just wonder?

I do all the time. I don't put much load on it while in gear and I keep the rpm low, but I do put it in forward and reverse to make sure everything's working. I've never had the water come out of the pee hole anything more than luke warm when I've had my 90hp mercury inline-6 running on the muffs.

 

[AZBoatDreamer]

Re: Running on Muffs.

I can push a button on the Throttle arm and I can advance the throttle without the Gear Drive engaged or the prop spinning. Isn't all boats equiped this way????

 

[bruceb58]

Re: Running on Muffs.

Always run in neutral only.

No reason you can't other than the possibility of someone/something being hit by the spinning prop. The only time that is really ever necessary is to check the shifing after changing/adjusting a shift cable.

 

[jondavies]

Re: Running on Muffs.

Regarding trimmed up vs. vertical: A buddy of mine keeps his boat in a slip and he used to flush his two-stroke Merc 225 in the trimmed up position at the end of the day. He was having motor problems and it turned out that the cooling water was flowing back up into the engine and causing the trouble (can't remember the specifics). The solution was to flush the motor in the vertical position, even though he has to get into the water to attach the flush hose.

 

[BTMCB]

Re: Running on Muffs.

I run mine on muffs after any salt water run. Drive is always down. Run it long enough to make sure the T_stat opens and then run "salt away" through it. Usually keep the RPM's at idle and / or less than 1,200 and always in neutral (don't want the prop spinning!). My mobile tech also runs it on the muffs in the driveway during service. He will also put it in gear from time to time for testing. Only reason NOT to put it in gear (that I am aware of) is to prevent any accident with prop spinning.

 

[scoutabout]

Re: Running on Muffs.

The manual for my 90 Yammy says nothing against running it in gear on the muffs - just to keep the revs down and watch the hose feeding it doesn't get sucked flat, choking off the water supply. I therefore do run it in gear at low revs to make sure everything works, check the prop and shaft for trueness or wobble, and give the gear oil a good stir prior to changing it.

They do, however, advise that a motor run on muffs have its prop removed - I'm assuming for safety.

When I owned an I/O I ran with the drive trimmed down as much as I could while on muffs to relieve strain on the u-joints.