Impellers

S

S Lightly Salty

Member
Sep 3, 2017
88
Boat Info
1987 Sea Ray Sundancer 340
Engines
Dual 454 Mercruisers
I’m pretty sure I know the answer to this but... We have an 87 340 Sundancer with 454’s. Bought from an elderly family friend with 500 hrs on the motors. This is our 2nd year with her and I’m trying to stay ahead of things. I have no clue how old the impellers are or if they have ever been replaced. Ran fine last year. Should I go ahead and have them changed as a preventative measure or wait until there is an issue?
 
Waiting until there is an issue isn’t as simple as a sudden over heat, which can either be a minor inconvenience or a disaster.

The real worry is that when an impeller fails it usually comes apart and the pieces get stuck here and there creating yet another over heat hassle that’s no fun to track down and fix.

If replaced as preventative maintenance every second year, you’re only replacing them (easy), not replacing them before clearing out all of the parts of the one you now regret not changing as P/M.

I say it’s $50 well spent.
 
I agree that you should change them because I had a failure on my port impeller early during my ownership that caused some overheating and mobility issues with 12 people on the boat, but I disagree with the comments that changing them is "easy." It isn't easy. At all. It's a giant pain in the azz.

I'm not sure if any of these people who claim they are "easy to change" have done it on an 80's 340DA, but the impeller housings are both very difficult to access; require many cuts, scrapes, and bruises to change; and will extract lots of 4-letter words. They are low in the engine room, tight against various walls, and most of the changing process is by feel and without being able to see anything. The water lines should have double hose clamps and can also be difficult to move around. The new housing helps since the old ones were multiple pieces that definitely complicated the process.

I'm not saying this as some novice that didn't know my way around the engine room. I've personally replaced the heads, cam, lifters, etc of one of the engines in the water, all 4 manifolds/risers, etc. If you're paying someone to do the job, it's well worth the money.
 
Rod Buster said:
I'm not saying this as some novice that didn't know my way around the engine room. I've personally replaced the heads, cam, lifters, etc of one of the engines in the water, all 4 manifolds/risers, etc. If you're paying someone to do the job, it's well worth the money.
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I can confirm that the experience described above was consistent on the '99 version 340 as well.

The impellers are cheap. The three priests, two rabi's and small child required to actually reach the water pumps are very expensive.
 
I agree with all of the above when I pull mine if they look perfect ( they usually do), they get thrown into my tool box as my emergency spare. Then when I change them again I give the old ones away and tell them throw this in your tool box you may need it one day.
 
Hmm,

I often forget what a PITA this job is for most.

“Mine” are easy...about 20 minutes apiece with no contortion or swearing required.

One of my requirements when purchasing this boat was that it was a piece of cake to work on, and with very few exceptions it is.

Didn’t mean to minimize.
 
Soulshine said:
Didn’t mean to minimize.
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Certainly not a problem, I just wanted him to know what he's getting into on an 80's 340DA. If it's his first time, it can easily eat a full weekend afternoon, if not more.

It sounds like he may be paying someone else to do it, which means my explanation will also explain why it isn't just $100 of labor. I'm still not sure how possible it is to do the starboard side with all the manifolds and risers installed. I luckily did mine when they were removed. I don't know if it can be reached from the transmission side, or if you should remove the port engine heat exchanger to go from the belt side. I'm cringing just thinking about it right now.
 
Soulshine said:
Hmm,

I often forget what a PITA this job is for most.

“Mine” are easy...about 20 minutes apiece with no contortion or swearing required.

One of my requirements when purchasing this boat was that it was a piece of cake to work on, and with very few exceptions it is.

Didn’t mean to minimize.
Click to expand...

Agreed. Engine room access is about the only reason I moved up from a 340 to a 400. :) Well...maybe not the only reason.
 
Well, karma is indeed a bitch.

I changed my impellers as preventative maintenance today. You might remember me opining on how easy they are.

One of them busted my balls for an hour trying to get proper belt tension. I couldn’t pull or pry it AND tighten the bolts to hold the tension. I have no idea how I accomplished this task last time or remember having trouble with it.

I channeled my inner Mcguyver and cooked up something to push the pump body off a stringer, but it was quite a contraption. Rube Goldberg would have approved.

Where’s my Scrotch?
 
I made it as far as pulling the belt and looking at the mess I’m about to begin. It sucks having the two impellers ready to install but knowing my limitations with patience. I reinstalled the belt and decided to wait for a “good” day. Cheapest quote was 2.5 hours each at $125/hr.
 
For $625 I’d do some yoga, sit in the lotus position, burn some insence, have a few drinks and become more patient.

I only really lose my patience after I have a hamstring cramp and hit my head for the 4th time.

Up until then I’m fine.
 
2808670-R1-015-6.jpg
Easy or not, do the PM. Or pay someone to do the PM. Too bad Merc does not make it easy as Crusader does.
 
It’s funny you mention that.

Despite having Mercruiser engines, I have Sherwood E35 Crusader pumps.

Someone in the past probably got sick of the originals.
 
LUnaCY said:
I made it as far as pulling the belt and looking at the mess I’m about to begin. It sucks having the two impellers ready to install but knowing my limitations with patience. I reinstalled the belt and decided to wait for a “good” day. Cheapest quote was 2.5 hours each at $125/hr.
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Your engine may be different than mine, but you shouldn't have to remove the belt to change these. The housing comes off without touching the pulley.
 
Never wait ! Changing the impellers is just part of preventive maintenance once you change them you know where you stand. If you ever herd the term if it aint broke leave it alone ! Well that doesn't apply in boating. lol
 
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