Running motor with impeller pump not hooked up

[ericcarr2000]

OK as many of you may know I just got done dropping the motor back in my 1990 Sundancer motor is a 7.4 big block question is before I first start it up would it be OK to disconnect the impeller housing so I don't chew up the impeller because I'm not a fan of muffs on my outdrive?

 

[HT32BSX115]

OK as many of you may know I just got done dropping the motor back in my 1990 Sundancer motor is a 7.4 big block question is before I first start it up would it be OK to disconnect the impeller housing so I don't chew up the impeller because I'm not a fan of muffs on my outdrive?

Howdy,

Nothing really wrong with "muffs" you know.......

Sounds like a Bravo. You want to pull the belt to the sea water pump and run the engine....(or it's an Alpha and you will pull the drive etc......)

Not a big deal........... but understand that HOT exhaust will heat up the exhaust manifolds, risers and rubber components on the risers and Y-pipe VERY quickly unless you connect a hose to the raw water pump output hose.

Regards,


Rick

 

[ericcarr2000]

Yeah it's a bravo 3. The thing is I've burnt up many impellers using the muffs. I've even bought the muffs that have s rod that goes all the way through the drive and still burnt it up. I just got done dropping s fresh motor in and just want to fire her up for just a minute or 2 is all then hook up the belt after that.

 

[thumpar]

I highly doubt it was running it on muffs that ruined the impeller. My B1 (same water system) is run on muffs before every outing for about 10-15 minutes to check things out. Are you changing the impeller routinely?

 

[achris]

Burning up impellers on muffs is usually caused by running the engine above idle, or very low water flow from the hose.
Not recommended to run the engine without water, even for 15 seconds. A minute or 2 would definitely see damage to shutters and other parts in the exhaust path. Unlike the engine, exhaust gasses are red hot instantly, there is no 'warm up' time.

Chris......