R-27 Impeller change

[knotflying]

I just changed my impeller on my R-27. It took me 1.5 hours with the help of another person. Below are the steps I took:

Tools
22 mm socket 3/8 drive
6 mm hex male 3/8 drive
3” extension
3/8 drive ratchet
Long needle nose plier
¼ inch drift pin or Phillips screwdriver of same diameter
Paper towel

• Shut seacock valve
• Turn off engine switch
• Disconnect engine positive wire
• Remove interior panel that has 110 and 12 V outlet. This makes sliding and removing slide panel easier and allows for better vision from side into engine
• Remove Impeller pulley belt – From cockpit side have one person push on belt at bottom of impeller pulley. Have 2nd person in cockpit on port. Reach into crankshaft pulley with 22mm socket, extension and ratchet. Turn engine clockwise (as if you were looking aft) and belt will work off.
• The following work is from cockpit side. Having 2nd person looking from inside helps a bit
• Turn impeller pulley so that pulley slots allow access to hex bolts
• Put a piece of paper towel on male end of extension and force hex socket onto extension. This will prevent the socket from falling off.
• Feel your way to the hex bolt and insert drive into bolt and then attach ratchet. Just loosen bolt, do not remove.
• Do this same procedure for the three remaining bolts.
• Now put a piece of paper towel on the end of the hex drive and force that into the hex bolt. If you loosened your bolts enough you can screw them out with just the extension and no ratchet.
• Once all the bolts are out you can slide the pulley and housing out and the person inside can handle it through the step access.
• Get a good set of straight needle nose pliers and insert them with one end in shaft hole and one end between blades and yank. Once you have it out half way you can turn clockwise while pulling out and you should have it in hand.
• There is a small O-ring type washer on the motor side housing. Mine looked good so I did not replace it.
• Insert new impeller by working it in turning it clockwise and inward pressure. Once started push it in.
• Now insert pulley and shaft assembly. Line up holes using the drift pin in one of the holes.
• Do the paper towel trick, using only the extension and screw in like you would a screwdriver and be careful not to cross thread the bolts. First turn counterclockwise then clockwise so as to be sure you are not cross threading and hand tighten. Do this for the remaining bolts.
• Now remove the paper towel piece in between the 6mm drive and the bolt and now tighten all the bolts using the ratchet.
• Now with the help of the 2nd person. Place the belt around the drive pulley and start it on the impeller pulley at the bottom
• Go back to your removal positions and turn the engine clockwise while the impeller person works the belt on.
• Visually inspect from the inside to be sure belt is on both pulleys appropriately.
• Reconnect engine power cable, turn on engine battery switch and open the seacock.
• Check for any leaks.
• Start engine, check that water is discharging, and look for leaks.
• Hi five and have a beer.

 

[Garry Anderson]

Bravo Bravo Bravo
I have printed and put in my boat book
Excellent! Thanks so much

 

[baz]

Thanks for posting those detailed instructions. I'm assuming this replacement process is similar to the R25's 4BY2-150 engine. It certainly seems so from my experience watching my technician do the same last year.

The paper towel 'trick' was brilliant. 🙂

When I'm not sure about some engine maintenance I typically have a technician do the work and watch carefully, take photos/movie of what is all being done and ask plenty of questions along the way. Then I feel qualified to do the work myself next time.

Can you say what the condition of your impeller was when removed and how many engine hours it had ?

Is the help of a 2nd person mandatory ? If doing this yourself how much longer would it have taken and what would be the issues if any ? I ask as when my technician inspected my impeller last year he did it by himself and it seemed to not be difficult. He removed all the hardware and inspected the impeller without removing it and in my case the impeller was in perfect condition so it was not replaced. This was with engine at 240 hours of use. He used a LED flashlight for the impeller inspection and found no hairline cracks and all the vanes were in good shape.

 

[trailertrawlerkismet]

Mike:

Congratulations on your impeller changing and a big thank you for the detailed instructions......they will come in handy as soon as the snow melts and boating season returns here in Northern Michigan.

Jim F

 

[knotflying]

There were 262 hours on my impeller. There were cracks in two veins, but no missing pieces. I would say the 2nd person is definitely a great advantage for the belt removal and replacement. Perhaps with a universal joint on the socket to the engine crank you may be able to do it with one person from the inside, but get a helper (I would recommend it not be a spouse) and life will be much easier.

 

[sleepyboat]

Mike,
You are located in a wonderful spot in Florida and had the perfect opportunity to make this job a guy gathering, beer drinking occasion, but being the overachiever that you are, you not only made it a timed event, but in pit stop style, set the bar high for everyone to shoot for! Thanks for the pressure buddy. Nice job!
John

 

[trailertrawlerkismet]

Today, with our Kismet sitting in our driveway, I changed out our impeller with 250 hours on the engine. I followed Mike Rizzo's step by step instructions at the bottom of this post and found it to be most helpful. With the help of a friend we were successful but unable to beat Mike's time of 1 1/2 hours, our time was 2 3/4 hours, but I was happy with that and know without Mike's step by step detailed instructions it would have taken much longer......Thanks Mike. I found the old impeller to be in great shape so I'll keep this for backup. In addition to this I found I needed 2 beers and some Advil to loosen up my muscles from all the contortions that are needed to make the impeller swap. Next time I'm shooting for Mike's 1 1/2 hour mark!

Jim

 

[sportner]

I did ours a few weeks back and it took well over two hours. I'm 6'-1", 210 lbs and somehow I squeezed my head and arms through that little hatch (after I removed it). I drank several beers after and was sore for days (not from the beer). The spousal unit helped or it would have been impossible, she gave directions for the ratchet on a few of the hex heads and helped remove the belt. If I ever attempt this again I will be the helper and I will find someone a bit smaller to fit in the hatch or I will remove the step completely as I have heard others have done.

The posted directions were very helpful, thankyou.

 

[walldog]

I did ours a few weeks back and it took well over two hours. I'm 6'-1", 210 lbs and somehow I squeezed my head and arms through that little hatch (after I removed it). I drank several beers after and was sore for days (not from the beer). The spousal unit helped or it would have been impossible, she gave directions for the ratchet on a few of the hex heads and helped remove the belt. If I ever attempt this again I will be the helper and I will find someone a bit smaller to fit in the hatch or I will remove the step completely as I have heard others have done.

The posted directions were very helpful, thankyou.

What a deal. Do you think we can get Willie and Toni to squeeze in that little hole? They will fit, but I do not think so. Mine is due to be changed any time now. I have been losing weight because I know it will be up to me. :lol:

 

[baz]

Today, with our Kismet sitting in our driveway, I changed out our impeller with 250 hours on the engine. I followed Mike Rizzo's step by step instructions at the bottom of this post and found it to be most helpful. With the help of a friend we were successful but unable to beat Mike's time of 1 1/2 hours, our time was 2 3/4 hours, but I was happy with that and know without Mike's step by step detailed instructions it would have taken much longer......Thanks Mike. I found the old impeller to be in great shape so I'll keep this for backup. In addition to this I found I needed 2 beers and some Advil to loosen up my muscles from all the contortions that are needed to make the impeller swap. Next time I'm shooting for Mike's 1 1/2 hour mark!

Jim

Jim: I'm glad Mike's detailed instructions helped you get the task done. I assume you were intent on changing the impeller because your engine had reached 250 hrs. Was this the reason ?

You say you found the old impeller "..to be in great shape...". So why did you change it out ? Did you simply want the experience of replacing the impeller? Having gone so far to get the impeller out maybe you said, what the heck I'll just place the new one in and suffer removing the old and inserting the new, which as I understand it can be a PITA. Why not leave the original in place and simply keep the new one as a spare and save some time and beat Mike's time ? 😉 :lol: This is what I did last September when my engine technician did our 250 hr maintenance and found the original impeller 'to be in great shape'. I have a brand new impeller as my spare.

No matter, it's good to read people doing this impeller replacement as a DIY project... and I'm sure we will always have Mike's detailed instructions burn into our brains over time. 🙂

It seems the R-25's cabin step which is completely removable with its lid wide open and the step riser removed makes an easier task for accessing the impeller housing, the impeller housing 4 bolts, the impeller pulley and it's belt. Is the R-27 one step backwards I ask ? :lol:

 

[knotflying]

Jim Favors wrote:
"In addition to this I found I needed 2 beers and some Advil to loosen up my muscles from all the contortions that are needed to make the impeller swap. "

And a few days later you will have black and blue marks in places you never knew you hit! I think that is a side affect of taking the low dose aspirin regimen. After working on my engine a few days earlier I went to the doctor for my annual exam and he asked if I was in a fight.

Glad to hear my step by step instructions helped.

Mike Rizzo

 

[trailertrawlerkismet]

Mike, I especially liked the paper towel piece inserted into the sockets parts and bolt heads to keep them in place while working my impeller magic. This is an idea that transcends to many different projects. To Barry's question as to why I did not leave the old impeller in......my thoughts are that as long as I've gone to all the work of taking things apart I may as well start off with a fresh impeller. Even thou the old one looked fine it still has 250 hours on it and therefore the vanes, in my opinion, would not be as resilient or long lasting as those of a new one and the way my body feels this morning I don't want to do this project again for a couple of years.

Jim F

 

[sportner]

We had a complete 250 hour service on our boat at Atlantic Yacht Basin near the Chesapeake two years ago while cruising from Florida to New York on the ICW. The impeller had cracks in the vanes and was replaced. In two weeks we will trailer the boat to Prince Rupert, launch, and spend two months cruising SE Alaska. When I did the service on Traveler a few weeks ago we had 465 hours on the engine but thought it best to perform it here rather than somewhere in Alaska. The impeller looked good, no cracks, but given the trouble to take it out I thought best to replace it here (in the comfort of my shop) rather than risk an overheated engine somewhere on our passage from Prince Rupert to Skagway. If these vanes break off and go to the oil cooler or into the engine, well, you could have some real problems. My advice... replace the impeller when you have it out.

 

[sportner]

Herb,

If you value your relationship with Willie you will continue to lose weight. Stock up on beer too. 😀

 

[nzfisher]

On the subject of impeller change. I had posted recently the the engine on my R25SC overheated. I did remove the impeller and all of the vanes except 2 were totally broken off/missing. I am lucky to have access to many boat mechanics, professionals, not just weekend guys where I keep my boat and their advise is free. They said that most likely the intake was blocked by something, weed, kelp, plastic misc. and caused the impeller to run dry. This will destroy an impeller in about a minute according to them. They also said that it is a good idea to get out all of the old parts prior to replacing. Not wanting to take too much of the engine apart, it is still a mystery to me how to get the metal cover off, I modified a tractor sprayer part to fit into the top zinc threaded hole in the block. I alternated filling this with water, then compressed air to blow out the cooling exchange system and recover the parts. After several, maybe as many as 20 iterations of both air and water I recovered all of the parts from a large piece of cheese cloth placed at the front end of the bilge. This saved me a lot of time and headache and is worth noting in case this happens to you.

Since I do use the boat in the ocean I have removed the fiberglass step and replaced it with a high density wooden step scribed to fit the old space so I have better engine access. I can now replace the impeller by myself in about 20 minutes and can probably do it at sea. In my mind an alteration well worth the trouble.

 

[Osprey]

Nzfisher wrote, in a post on May 15, 2013 9.43pm: “… I modified a tractor sprayer part to fit into the top zinc threaded hole in the block. I alternated filling this with water, then compressed air to blow out the cooling exchange system and recover the parts. After several, maybe as many as 20 iterations of both air and water I recovered all of the parts from a large piece of cheese cloth placed at the front end of the bilge...”
One would need to be very are careful carrying out this back flow flushing of the raw water system. If excess water were added, water could fill the exhaust line and muffler to the point where water would enter the engine. (Similar to what happens if one runs the starter too long with the engine failing to start i.e. the 10 second rule.) Perhaps nzfisher could post how he added the water in a way that ensured that no water entered the exhaust/muffler system.

 

[nzfisher]

This flushing was done with the impeller removed and the first flexible rubber pipe that goes to the impeller housing removed. This is the low point or nearly the low point of the raw water system. The water is free to flow out this area while flushing. The water is allowed to flow through the fitting into the top engine zinc hole, then before all of the water flows out I used compressed air to push the remaining water, and hopefully the vanes, out of the system at the impeller housing. I don't see how the water could flow into the exhaust system as it would be fighting gravity but I guess it is possible. After the this process was completed, all parts were reinstalled and the engine tested by maintaining a filled engine strainer cup with fresh water. The system has been out in the ocean for about 30 hours of run time as I have gone offshore at least 20 miles a couple of times. So far so good. Osprey, If you think the process is flawed please let me know.

Thanks

 

[sportner]

nzfisher, I would be interested in seeing photos of your step modification when you have time.

 

[HRowland]

I changed the impeller on my 4BY2-180 today. I did it solo from inside the cabin. I was able to get my shoulders and one arm through the access hatch under the step. I could use my right arm to assist by reaching through the opening in the cave where the panel with 12V/110VAC outlets is. Using this method I could turn the crankshaft with my right hand while working the belt with my left.

The original impeller looked perfect. It had 215 hours in 2 1/2 seasons, including two winter layups with antifreeze in the raw water system.

Thanks to Mike for the tip about paper towels in sockets, nothing fell.

I am a little sore across the front of my chest from lying on the edge of the hatch opening but no other injuries. I even avoided cutting myself on any rough fiberglass!

Howard

 

[baz]

Howard…. well done and congratulations on a job well done. It really is an experience and as you know, there are wounds to be healed afterwards. :lol: