And, no, the RWP won’t affect the distributor as the two systems are unrelated.  It’s like saying that a flat tire made the power windows stop working.  Unrelated. The RWP will certainly impact operating temperature of the engine, and high temps can and will impact other engine systems. 

JQ

I also change the impeller every 2 years.  For $35 and 30 minutes labor you can trust it to work every time.  Always carry a spare in the boat.   Call it insurance for great days on the water!

I feel those who have blown impellers have run them dry. 

Pete Here's a quote from you in 2010 with the same picture. There's obviously some  BS being spread by you.

Get your sheet (as the Mexicans would say it) straight 

Those are 2 fairly ugly looking impellers too.
 

The hotter states are much harder on impellers than the cooler states. We probably have 90 days over 90* and another 70 over 80*.  Equal to about 3 or 4 of your summers every year.

Every time I try for 3 seasons on an impeller in CA I pay the price with impeller failure.  My local boating buddies follow the same advice.  I will stick with every two years in CA.

Ugly? If you say so, but here's the key:

8122pbrainard wrote:    I had no cooling problems

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Keep it original, Pete
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You airplane guys are always funny. I suppose you follow Sherwoods maintenance schedule to the letter?  

In my old '96 (purchased new), I ran the first impeller to about 450hrs before it disintegrated out in the California Delta at a slalom course.  Had a spare and was skiing again in 20 minutes.  Next one lasted another 400+hrs and it disintegrated at Santa Clara County Water Ski Club's site.  20 minutes later I was skiing again.

Is two years (or 200hrs which is what I do now) overkill?  Sure.  Was it smart to just run it until they died?  No!  It was stupid.  I could have clogged up channels in the engine with rubber, etc. or otherwise screwed up the engine.  While I always have the spare and the tools to do it in the boat, why do I want to risk overheating, not to mention disrupting a day on the boat?  

I agree, cheap insurance.

However, we can talk RWPs and impellers all day, but without a working gauge, we don't know.  After oil pressure, temp gauge is the most critical and I would not run my engine without both working.

And since the RWP has nothing to do with an exploding rotor, the pump and impeller are 'possible' additional issues.

I'd figure out the rotor issue (check with shaft play as mentioned).  See if there is any rubbing/wear indications inside the cap (was the cap seated properly?).

You said the lady you bought it from said 'it' was happening last year.  What is 'it'?  Rotors decimating themselves?  Or just occasional rough running/missing?  If the rotors have been trashing themselves, I would have wanted to get that resolved before buying the boat.  But that's water under the bridge.  Let's figure out the rotor/distributor issue first.

I'd then get the temp gauge fixed (I'm assuming the oil pressure gauge is working, if not, fix that first and then the temp gauge).  If none of your gauges are working, could be a ground or power issue in the dash, but I would not drive blind.

BTW, does your boat have the top center dash 'check engine' light?  If so (and those sensors are working), you do have back up temp and oil pressure notification/limp mode.  But get those gauges fixed!  :)

As soon as I start the engine, I immediately put my hand on the BACKSIDE of the RWP.  If it is not pumping water, it will get HOT very quickly due the impeller friction.  If water is flowing, it will stay cool.  Quickest way to check the pump/impeller.  Of course, if the impeller has disintegrated, that may not work unless there are still a couple of vanes turning against the housing.

Pix of the check engine light:

slmskrs wrote:   I'd figure out the rotor issue (check with shaft play as mentioned).  See if there is any rubbing/wear indications inside the cap (was the cap seated properly?). You said the lady you bought it from said 'it' was happening last year.  What is 'it'?  Rotors decimating themselves?  Or just occasional rough running/missing?  If the rotors have been trashing themselves, I would have wanted to get that resolved before buying the boat.  But that's water under the bridge.  Let's figure out the rotor/distributor issue first.

You obviously missed the point that your stories don't seem to agree from one post to the next when you get to telling the world how many years you go without doing things like checking impellers, points etc and you seem to forget about the years that your "trailer queen" or maybe "beam queen" never hit the water or got minimal use

You Pete are truly, the "king of preventive maintenance".

Hopefully every new owner that shows up here with questions follows your sterling example of how to take care of his boat 

Maybe some guys never have guests over. Seems that is when an old impeller shreds, or the cable pivot finally saws on half.... 

I ski, not just boat. I take others skiing and i'm not the exclusive driver, i let others take the helm. 

 last thing i want to tell a driver is to watch that temp gauge. that implies its the most important thing. Especially when my daughter pilots im thankful she has since she was 15. She just would never have been a participating driver if i told her to watch the temp gauge every time i drop in.. just wouldn't. Then gottaski cant ski. not good. 

 I expect a pilot's full focus on the safety of passengers, the craft, the shoreline, the rogue 60 mph pontoon boat that doesn't yield, or occasional lake lice that think its fun to mess up the 6am water.  whatever is left over, goes to my ski experience. I'm not giving that remaining faculty to a temperature gauge to save 30 dollars every other season.

Pete, i see your pump there,  shaft is supported on both ends, i suspect that keeps everything in place with high precision throughout its lifetime.. I've had the dual pumps on a Chrysler apart many times as well, same config.

On a old single circuit Sherwood, when the bearings get a little worn, the shaft torques over from belt tension a little, so on a LH engine this moves the impeller away from the wedge, creating low volume condition even with a fresh impeller, that can be maddening but more a nuisance because its mostly at idle until it gets worse, but very challenging to diagnose...

Conversly, i suspect, on a rh engine  the pump is flipped as you know and the impeller is now mashed toward the wedge more than usual, creating great flow at first,  but as it gets worse this decreases longevity as the vanes see very big deflections and can start to run out of room. So, in some contrast to your axiom,  that is one way i see impellers can shred early, without starting the boat without water applied. 

Also, with the advent of lifts, some boat's pump configurations drain out and start dry every use. this happens

 even when dropped in the water, it starts dry, and eventually doesn't draw. Impellers wear early, when the temp spikes a few times and outing, its going to shred soon. 

this happens to a ski buddy's centurion lapoint with a mercruiser 350 .

the pump drains out every time its lifted.

burns up  1-2  run-dry impellers a season with just daily use.

there is a simple solution of course, but some don't commit to modifying items asap

Besides the engine lol

Gary enlighten us. you going to keep at it and remove all doubt?

Looking at my GT-40 engine, there is a low spot in the raw water hose leading up to the RWP. It looks reasonable that there is some amount of residual water In the hose.  I pull pull my boat out of the water after every ski session as I trailer to/from the lake.  As such I’m glad to see that lubricating water is not far from the RWP on start-up.

As for servicing the Sherwood RWP....well on my old 1994 SNOB, I attempted to do a major rebuild on the pump, but crashed and burned on take-off.  At the time I didn’t have a hydraulic press required to properly disassemble and reassemble the pump and I ended up cracking the pump housing.  That cost me a $400 RWP.  I still have the rebuild kit and may attempt a rebuild on the new SNOB when engine hours indicate a major rebuild is due (based on Sherwood service hour recommendations).  

As the impeller kit is only $25 and 10 minutes to install, this is a periodic service item I do every couple of years.  Overkill?  Perhaps.  I look at it as a modest insurance premium. 

JQ