Kiwi Prop

[russp]

I know there has been plenty of discussion about the Kiwi prop in past postings, but I have just fitted one and have problems and wonder if anyone else experienced similar.

The manufacturer had full specs for engine/gearbox/boat from me, and claims to have lots of previous installations in Catalinas, so I assumed that the setup of the prop (i.e. diameter and pitch) would be reasonably well suited to the boat as supplied. To my dismay:
1) WOT is now 2000 rpm so it is massively overproped as supplied (I know I can adjust the pitch if I can find a diver or lift the boat again)
2) almost non-existent vibration or engine shake above 1400 rpm with original 15x9 sailprop is now vibration through the whole hull and rigging - installation was done with oversight of a marine mechanic and the boss fitted the shaft perfectly so definitely not loose or off-centre. The dealer painted the prop and blades with Propspeed prior to delivery so I am assuming that doesn't put it off balance.
3) when engaging reverse (idle is around 1000 rpm to reduce damper plate chatter and engine vibration) there is a pronounced "bang" which is scaring the hell out of me and making me think of bits of gearbox all over the boat.

I can return for refund within the first 30 days, but that puts me out of pocket and still with problems of original 15x9 sail prop. Any thoughts gratefully received.

Russ Peel
Avalon #150

[elk]

I'm assuming that the pitch shown in the picture is not the way in went into the water? That is the feathered position? Please clarify.
-----------------

I know there has been plenty of discussion about the Kiwi prop in past postings, but I have just fitted one and have problems and wonder if anyone else experienced similar.

The manufacturer had full specs for engine/gearbox/boat from me, and claims to have lots of previous installations in Catalinas, so I assumed that the setup of the prop (i.e. diameter and pitch) would be reasonably well suited to the boat as supplied. To my dismay:
1) WOT is now 2000 rpm so it is massively overproped as supplied (I know I can adjust the pitch if I can find a diver or lift the boat again)
2) almost non-existent vibration or engine shake above 1400 rpm with original 15x9 sailprop is now vibration through the whole hull and rigging - installation was done with oversight of a marine mechanic and the boss fitted the shaft perfectly so definitely not loose or off-centre. The dealer painted the prop and blades with Propspeed prior to delivery so I am assuming that doesn't put it off balance.
3) when engaging reverse (idle is around 1000 rpm to reduce damper plate chatter and engine vibration) there is a pronounced "bang" which is scaring the hell out of me and making me think of bits of gearbox all over the boat.

I can return for refund within the first 30 days, but that puts me out of pocket and still with problems of original 15x9 sail prop. Any thoughts gratefully received.

Russ Peel
Avalon #150

[yodagwb]

The first thing you need to do is get the pitch adjusted down and then see where you stand. A guy I know was over proped with first a Gorie and then a Flexofold and with both he got substantial vibration as he throttled up and he wasn't as over proped as you appear the be if WOT is 2000rpms. What size prop did you get and what is the pitch set to?

[chesworth]

I installed a Kiwi Prop last season and have been very satisfied. Unit has 16"blades and was set to a 21 degree pitch. WOT is 2800-2900 rpm on Universal M35B engine ( motors well at 6-6.5 KTS at 2200-2300 rpm). I sail in Great Lakes and have not coated prop with antifouling. The boat is stored on the hard in the winter. I found that the greasing in the Fall, through the blade grease points, had partially forced out one of the O rings at the base of the boss. Over the winter the O ring became distorted. The local Kiwi agent provided replacements rings and recommended that in future the blades should be removed to grease rather than using grease port. I also found some wear on the blade retaining pins and therefore rotated then when reinstalling,they will probably need replacing after 4-5 seasons.
Alan
Hull#341

[russp]

Hi Ed, yes can confirm that when I took the picture the blades were in the full reverse position (in which it looks more like a fan than a prop - the guys in the slipyard couldn't believe a prop could work at all with that much pitch). Kiwi state that you do run the revs much slower in reverse, and that the prop can overload a smaller motor and you can see why!

The boat does reverse with this prop, and at very low revs, but it has a huge amount of propwalk, more than the 15x9 I took off, whereas some previous posts said the prop walk was reduced with the change to the Kiwi so I am quite confused at present.

Thanks for your comments Alan, my receipt says they delivered a 16x21 deg RH 1" and therefore identical to yours (in spec at least). How on earth can they be so different? The blades must be going to the full forward position as they moved easily with gravity when rotating the prop in the yard

I am waiting on comment from Kiwi Prop, haven't heard in 2 days but hopefully they are thinking about it. Until I hear from them I am not going to start adjusting the pitch as it should be correct as it is.

Regards
Russ Peel
Avalon #150

[leigh weiss]

Russ.
As I recall the prop goes in reverse and backs up against the spring. This allows the prop to assume a more realistic pitch.

Leigh Weiss Brisa #155
Georgetown MD USA

[russp]

You are correct of course Leigh, I spent some time last night on the Kiwi Prop site and read up on how it reverses and while you can't "see" it in reverse pitch when stationary on the boat, it obviously works once water pressure is on the hub/spring mechanism through the blades.

I got down below this morning when it was being put into reverse and was relieved to hear and feel that the loud bang (to my ears) is in the prop and I couldn't feel it in the gearbox casing so presumably that is the spring hitting the stops in reverse. I hadn't heard any mention of this from other owners but Kiwi Prop have since confirmed that there is an audible "knock" when the reverse dog engages, but presumably most owners don't notice or don't worry about it.

The KP guy suspects that I only have a 30 HP M35 or M35A but all the documentation I received with the boat confirms a 35B with 27 kW or 35 HP so no logical reason there for the 2100 rpm WOT, and at 1200 hours and no apparent damage to any part of the engine no apparent reason for any power output restriction. We just fitted a new exhaust riser and hose and looked into the exhaust manifold and nothing untoward has happened in there. So at this stage a mystery I am still working on.

For interest, my mechanic sand blasted the inside faces of the riser, there was extensive pitting on the discharge side and he noted small white crystals in the corresponding face on the dry side that he says is salt starting to weep through the metal even though there appears to be plenty of metal left. To be safe I bought a new riser.

Russ Peel
Avalon #150

[leigh weiss]

Russ,
If you replaced the 15x9 three blade fixed blade prop with a 16x21 Kiwi, then it seems that you have over done it a bit on the pitch. I don"t know what my pitch is now because I adjusted (fine tuned ) it in the water. I think you have to do the same.
I also lowered the idle to 900 RPM (with an optical calibration tachometer), after the new HD flex drive plate, and the "Clunk" is not as pronounced.
Remember to check the front edge of each blade to the hub seam, making sure that the visual gap distance is equal for blade pitch balance. I adjusted my pitch first with a full turn of the screws, (easy to see with the wrench in the water) tested, and readjusted. I wanted to go past the optimum point and then fine tune at 1/4 turn per readjustment.
Please keep us informed with your progress on your quest for engine speed, smooth and quiet.


Leigh Weiss Brisa #155

[Pgtjs]

Hi Russ,

I tried to submit this a couple of days ago and was rejected by a log in problem so it may be a bit dated.

I have a Kiwi prop and have referred your query to the retired Kiwi dealer in Vancouver. I will forward his reply as soon as I hear - we belong to the same yacht club.

When my prop was first installed I had problems in overheating above 2600rpms as it was overpitched. As I recall it was overpitched by one or two degrees and the dealer adjusted it on the next liftout - it can be done in the water if the diver really knows what he is doing. You seem to rev high when idling at 1000rpm whereas I rev at 850rpms and do not get a significant clunk when I switch into reverse. I have a Yanmar 30hp engine and Hurst transmission. I run the engine at 2900 rpms or about 90% of capacity per the Yanmar recommendations and this ensures full fuel burn - ie no black smudge - and I get about 6.5 knts in calm conditions.

Incidentally I put regular anti fouling on the prop and that seems to work just fine but the dealer does not insist such is necessary. I also installed a one inch "shaft saver" on the shaft up at the transmission flange and that gave me plenty of clearance to install the dough nut zinc. Also IMHO, the saver should be mandatory around here as protection if you hit a log or other flotsam - the blades break off by design and one does not bend the shaft or damage the transmission. Perhaps this is not an issue where you are?

I will forward the dealer's reply when received.

Cheers, Geoff. C350-#392, Taeko 1V Blaine WA. USA.

[Pgtjs]

Hi Russ,

Re my previous reference of your query to the retired Kiwi dealer in Vancouver, I have received the following answer:

..."Hello Geoff,

Sorry for the delay in getting back to you.

Your prop size is 16.5" diameter x 22degree x 1. By backing it off 1/4 turn, revised pitch is just over 21 degrees.

See you on Saturday at Thetis.

Cheers,

Norm".

As mentioned I was having an overheating issue at higher revs but Norm adjusted the pitch by 1 degree (1/4 turn on each blade) and that small change has solved it completely. I idle at 850rpm and do not have a clunking problem when shifting into reverse.

One other point for all Kiwi prop owners - they do need to be greased on each liftout. I was ignornant of this and neglected to do this for more than two years and it was barely still lubricated when Norm came by to adjust the pitch. A fine tipped grease gun with marine grease is all that is needed and read the instructions.

Cheers, Geoff. C350/392 Taeko 1V - Blaine WA.

[Pgtjs]

Hi Russ,

Re my previous reference of your query to the retired Kiwi dealer in Vancouver, I have received the following answer:

..."Hello Geoff,

Sorry for the delay in getting back to you.

Your prop size is 16.5" diameter x 22degree x 1. By backing it off 1/4 turn, revised pitch is just over 21 degrees.

See you on Saturday at Thetis.

Cheers,

Norm".

As mentioned I was having an overheating issue at higher revs but Norm adjusted the pitch by 1 degree (1/4 turn on each blade) and that small change has solved it completely. I idle at 850rpm and do not have a clunking problem when shifting into reverse.

One other point for all Kiwi prop owners - they do need to be greased on each liftout. I was ignornant of this and neglected to do this for more than two years and it was barely still lubricated when Norm came by to adjust the pitch. A fine tipped grease gun with marine grease is all that is needed and read the instructions.

Cheers, Geoff. C350/392 Taeko 1V - Blaine WA.

[russp]

Thanks very much for the information passed on Geoff. There is an ongoing uncertainty about all of this. The Kiwi Prop supplier is sure that my 16" prop left the factory set to 21 deg and therefore by your experience it should draw less power than your 16.5" set to 21 deg.

However, we ran trials yesterday in flat water and the M35B and Hurth 1.88 reduction gearbox combo on my boat tops out at 2300 rpm and about 6.3 knots and the engine is working hard but otherwise seems in perfect order and I had a diesel mechanic on board. Thus 21 deg pitch is still too much and next step is to knock it back.

I am also planning to cut the idle speed back (it is high to prevent excessive engine shake at idle and breakage of alternator mount, heat exchanger mount and fuel filter mount - all had broken or broke soon after I purchased the boat and nothing since I replaced them and upped the idle speed). I can start to use the throttle instead so that I only allow the slow idle for moments between gear changes and keep away from it the rest of the time. It is logical that a high idle speed will increase the impact when the rotating hub/spring combo in the prop hits its stop.

The further I look into this the more I accept that the "small" and quite light 15x9 prop that comes with the boat allows for a certain degree of misalignment or off-centre to be tolerated but it would appear that the heavier hub of the kiwiprop accentuates any imperfections so I may have to go through and do a complete alignment/balance/damper replacement/PSS maintenance kit install all at the same time, and with luck and good management she will go back in the water as smooth as silk.

The amount of water pumped in reverse is massive compared to the 15x9 sail prop and I haven't even had a chance to explore the improved sailing performance yet.

Again, many thanks for the input, most things are starting to fall into place, this has just turned into a much bigger and more expensive project that I was anticipating (but then again, what to do with a boat doesn't!!).

Russ Peel
Avalon #150

[yodagwb]

As far a the broken fuel filter bracket, that was a casting issue in the earlier models, I think most of them broke. Once replaced there shouldn't be a problem. The shaking at idle is a bit odd. Any misalignment, be it engine or prop , should be much worse at higher RPM's. The one thing that should be worse at idle is the rattling of the damper plate. Before changing it I relied on putting the boat in and out of gear as opposed to a low in gear idle. Does it shake in neutral?

[russp]

Hi Yodagbw,

Time obscures facts! You are correct in that the primary reason for increasing the idle about 3 years ago, you now remind me, was to reduce the damper plate chatter. At 1000 rpm in neutral the engine is smooth as silk, no movement whatsoever. I can't remember if it shook at 850 rpm or whatever it was originally, but I am going to slow it down again and will soon know.

I am not sure that you are correct about prop or shaft misalignment being much worse at higher revs, I think momentum and gyro effect start to come into play and the vibration is suppressed at higher revs, or may also be some sort of resonance with the engine mounts at lower revs which doesn't happen higher up.

At 1000 rpm with forward engaged and the kiwiprop fitted the engine in bucking vertically on its mounts but by 1500 rpm the amount of movement, and the vibration felt throughout the hull, is greatly reduced. I plan on doing whatever is necessary to get rid of it anyway, am planning to adjust pitch first and see what vibration is like then and then if necessary pull down and rebuild the drivetrain.

Regards
Russ Peel
Avalon #150

[yodagwb]

Russ

At hull # 150 you are probably some where around the 10 year mark. Don't know what your engine hours are like but don't forget to make sure your cutlass bearing is OK.

[leigh weiss]

Russ,
I suspect the alignment is your culprit.
As I recall you replaced the drive plate with a HD drive plate and had to raise the engine to do the job. There is some latitude for mischief in the alignment when you disturb that ecology!
I think you have checked all the other parts (cutlas bearing and engine mounts)
and have adjusted the pitch to get full RPM at WOT in gear.
I ran the boat yesterday and have the Idle at 900 RPM
Everything is smooth and quiet up to WOT in gear. No excessive engine motion with my KIWI.
I know how frustrating it is to chase down the root cause of this problem.
Let us know how you are doing and hope you can do a victory dance soon.

Leigh Weiss Brisa #155

[william vanwagoner]

Any updates? I am thinking about getting a kiwi as well, and it sounds like 15 inch blades may be the way to go. I note that someone used a drivesaver to move the shaft rearward - which with the Universal it doesn't seem like there is enough space for it given the close proximity of the shaft seal. Also, on my boat the cutlass bearing extends out of the skeg and doesn't leave much room for a donut zinc so I have been relying on the cone zinc which does not appear to be compatible.

[leigh weiss]

Bill,
The drive saver I tried to install did not fit !!
The Kiwi Prop does extend the blades aft enough for more clearance from the deadwood to the blades. This might help with the cavitation noise. See Russ P. pix above!!!
Since the new HD drive plate and the Kiwi prop, all is quiet and vibration free. I don't think I will
try to install any type of "Drive Saver" for now.
I hope Russ had success with his new drive plate and Kiwi prop and waiting for his report.

Leigh Weiss

Brisa #155
Upper Chesapeake Bay MD.

[Pgtjs]

Hi folks,

As mentioned in earlier posts, once I got my Kiwi prop and shaft-saver in place and adjusted, it works fine and there are no vibration issues. Per the invoice it is a KF3RH16.5x22x1 and the shaft saver was from West Marine Item # 3684891, both dated 2007. It was adjusted by the dealer by backing off the pitch by 1 degree from whatever the factory shipped. It is mated to a Yanmar 3YM30 with a Hurst Transmission. I can run all day at 2850 revs and about 6.5 knts through the water. Without the shaft saver there was not enough room for the doughnut zinc to fit on the shaft. You must also wire over the saver from the prop shaft flange to the transmission flange to ensure the shaft is grounded to the engine block etc. - an electrical engineer insisted I should do this and I've had no problems in this regard. The Zincs seem to last a full year.

The only issue I have had since was the internal spring broke last year and so it would not flip over to reverse the blades. It took a lift out to fix and I was told by the dealer that the later KWP products had changed and improved the conical fitting which holds the spring. The prop has always had strong port side prop wash in reverse which I find just great when going into finger docks and when pulling the stern into tight spots. I do not rev the reverse drive much at all - just a little forward then a little back and I can move sideways a few feet in stable conditions.

Cheers, Geoff. C350 # 392 Taeko 1V Semiahmoo WA

[nybor]

Russ, et. al.

Don't you see what is going on with the Kiwi prop?????? As you are well aware, the Kiwi cat just crushed Prada in the Louis Vuitton cup in S.F. yesterday. Of course, these AC 72 boats cost a fortune. So, the Kiwis are trying to recoup their investment by selling props that need a lot of servicing - for a price. (my opinion - just in case the lawyers in New Zealand are reading this).

dave "go Oracle" bloomquist