Stupid mistake: bravo III

[rock doc]

Installed a brand new impeller last week. Was getting the boat ready to launch and long story short ended up running the drive for under a minute without the water turned on to the muff (stupid).

I turned the water on and everything seems fine. Searched this forum and seems these impellers are really delicate and can be damaged in seconds. I had a closer look at the pump and wouldn't some water flow under gravity back to the pump at idle if it ran without water for a brief period? Should I pull the impeller? It is really difficult to get to...we have a 7.4l in a 23' cuddy. To say it is tight is an understatement. Sometimes I wonder who designs this stuff because it would not take much to make this pump more accessible.

 

[achris]

Personally, I'd pull the pump and check (with a view to replacing) the impeller. Regardless, that impeller has a shortened lifespan now.

As for the pump being difficult to get to. Has to be that way. You can't mount the pump any higher as it needs to be lower than the vessel waterline to 'prime'.

Chris...........

 

[rock doc]

thanks...I was in denial. It took a full day to swap it out. There is no room to get around the bulkhead so everything must come off to get at it. Lesson learned...I will never buy another boat with a doghouse this tight. I feel for mechanics that have to deal with this stuff.

 

[jimmbo]

thanks...I was in denial. It took a full day to swap it out. There is no room to get around the bulkhead so everything must come off to get at it. Lesson learned...I will never buy another boat with a doghouse this tight. I feel for mechanics that have to deal with this stuff.

They are at least getting Paid a small percentage of the money charged to suffer.

 

[achris]

thanks...I was in denial. It took a full day to swap it out. There is no room to get around the bulkhead so everything must come off to get at it. Lesson learned...I will never buy another boat with a doghouse this tight. I feel for mechanics that have to deal with this stuff.

Good luck finding one. The manufacturers make them that way because the consumer demand is for more deck space. As a relatively small percentage of owners do their own maintenance, the major demand by the buyers is for SMALLER engine boxes, not larger....

Chris...

 

[havoc_squad]

They are at least getting Paid a small percentage of the money charged to suffer.

Oh, it gets better when:

1. It's your personal boat
2. It's only one or weeks until scheduled outing.
3. You screwed up the original needed repair/maintenance
4. Because of that screwup, the Admiral (wife) looks at you more angry than a disgruntled customer who got 30% overcharged on a $2k repair.
5. If it's not ready on that soon deadline for her visiting friends, a month of misery for you shall be mandatory.


It's a shame when doing service work you see people get so bent out of shape of unrealistic expectations for material possessions that do not mean life or death.

 

[scoflaw]

I've done that more than once for a minute or 2 without any negative effects. There's always water in front and behind the impeller when the engine is off. So it's not like its dry, and it's a rugged piece.

 

[Lou C]

Have to agree on the lack of access for maintenance. Either you have the tight doghouse or have to remove the rear seats and bulkhead(s). I've seen a lot of I/O boats at boat shows I'd never buy because of the poor design. The engine mounted impeller is bad enough, what about starters or anything on the rear of the engine? The only real easy one to do I've seen is the OMC Cobra, right under a plastic cover at the rear of the upper gear housing. If you're careful you can even do it in the water with the drive tilted all the way up!

I'd agree with replacing it, it may move enough water at low speeds but might not at high speeds. These systems are not high pressure but need a large volume of water in and out to keep the engine and exhaust in the right temp ranges.

 

[tpenfield]

FWIW - Here are the design guidelines used for I/O boat engines . . .



Some outboards aren't much better

If you ran the engine for more than 5-10 seconds w/out water going to the muffs, then I would check the impeller, as mentioned, to be sure. When I install an impeller, I use dish liquid to provide some initial lubrication. Also the AF from winterization can do the same thing,

Any water that is further along the input flow from the water pump is really not going to help, since the Bravo pumps will tend to push air through them due to the tight fitting impeller and dry out quickly in the absence of water.

 

[rock doc]

Bought the impeller and housing. Try to swap it tonight. Just for interest sake I asked what it costs to change the impeller...approx. $250 labour.

Hoping I can get it swapped in 2 hrs if I focus. We shall see. Last time took me better part of a day. Now I know just pull stuff off...waste of time trying to work around the fuel filter etc. I had read some people dont even fully pull the pump but that is impossible in this boat.


Worst thing is the original impeller I replaced looked brand new. Not a mark on it. If only I had x-ray vision.

 

[scoflaw]

Worst thing is the original impeller I replaced looked brand new. Not a mark on it. If only I had x-ray vision.

I'll bet the one you take out tonight looks the same way.

 

[jimmbo]

Definitely describes what you get when you get married.



Later you will appreciate why Divorces are so Expensive. Cause they are Worth it

 

[rock doc]

I'll bet the one you take out tonight looks the same way.

AGREED - but it is a boat and I will stress over this if I don't pull it. My neighbor is always entertained - he thinks I'm nuts to do all this preventative maintenance, esp considering the boat does not even come up to temp on the muff currently.

I'll know soon enough. Trying to maintain the motivation to stand on my head and change this impeller blind instead of just launching it and wet testing it. I ran the boat on the muffs just last week after I changed it out so the new impeller should not have been completely dry at startup. Only one way to know for sure though!

 

[havoc_squad]

AGREED - but it is a boat and I will stress over this if I don't pull it. My neighbor is always entertained - he thinks I'm nuts to do all this preventative maintenance, esp considering the boat does not even come up to temp on the muff currently.

I'll know soon enough. Trying to maintain the motivation to stand on my head and change this impeller blind instead of just launching it and wet testing it. I ran the boat on the muffs just last week after I changed it out so the new impeller should not have been completely dry at startup. Only one way to know for sure though!

I bet that neighbor is the same person that when they cook their boat motor due to lack of scheduled maintenance, they ask for a "tune up" after describing overheat symptoms.

The dude doesn't recognize he probably lit $4k worth of money up like a match for being lazy on maintenance.

Ran into that once of a customer with the service manager while I was asking around at a local boat service shop to see if there were any good local outboard machine shops nearby should that need arise.

The service manager replied to that customer overheating his outboard... "Well, we'll do a compression test on it and let you know what it's gonna take".

 

[scoflaw]

AGREED - but it is a boat and I will stress over this if I don't pull it. My neighbor is always entertained - he thinks I'm nuts to do all this preventative maintenance, esp considering the boat does not even come up to temp on the muff currently.

I'll know soon enough. Trying to maintain the motivation to stand on my head and change this impeller blind instead of just launching it and wet testing it. I ran the boat on the muffs just last week after I changed it out so the new impeller should not have been completely dry at startup. Only one way to know for sure though!

It's a learning experience. You pull it out and it looks new , you learn about the thresholds of what that part can take. I have had very good luck with accidental abuse of that nature.

 

[thumpar]

It gets easier the more you do it. I don't have to take as much off my boat anymore because I can feel the job now. Last year I installed it 3 times because the first time I found an o-ring I left out and the second time I mounted it upside down. It helped when I first starting doing them to have a son that was 9 to crawl in the tiny spots and get the wrench on for me.

 

[tank1949]

Bought the impeller and housing. Try to swap it tonight. Just for interest sake I asked what it costs to change the impeller...approx. $250 labour.

Hoping I can get it swapped in 2 hrs if I focus. We shall see. Last time took me better part of a day. Now I know just pull stuff off...waste of time trying to work around the fuel filter etc. I had read some people dont even fully pull the pump but that is impossible in this boat.


Worst thing is the original impeller I replaced looked brand new. Not a mark on it. If only I had x-ray vision.

IT sounds like you'd be better off if you went ahead and designed an access plate or bulkhead to be easily removed. I am restoring a vintage SR that has dual Bravos with crank shaft water pumps. No room at all to access pumps to change impellers. So I cut out a bulk head access panel just in front of motors. You can buy starboard to make it look pretty. Trust me!.

 

[rock doc]

Great idea but the pump is blocked by a structural member/stringer. I don't think it is something I should cut.

 

[rock doc]

just thought I would provide an update based on my experience on this issue. The impeller was undamaged after approx 1 min of runtime with the water turned off. It is soft and zero evidence anything got hot.

I will keep this as a spare on the boat.

 

[tpenfield]

just thought I would provide an update based on my experience on this issue. The impeller was undamaged after approx 1 min of runtime with the water turned off. It is soft and zero evidence anything got hot.

I will keep this as a spare on the boat.

Yes, I have taken out 3 year old impellers and they look fairly new . . . they make good emergency spares.