Murphy at work on my prop

[Mr O]

The maxprop on my boat was making noise so I put on the dive gear for a look. It was about ready to fall off! Without a travel lift nearby, the only option was to remove it while in the water. Not wanting to loose a very expensive prop to the bottom mud, I hired a competent pro to remove it. Things went well and no parts other than a few tiny split pins were lost. The diver put the fixed blade prop on and away we went. The maxprop has yet to be installed and I miss it.

Anyway, don’t worry to much about the settings. Call or email PYI for settings info for your engine/boat. They can also refurbish your prop, if needed. Mine is 19 yrs old and needed some brazing on a few gear teeth. I considered upgrading to the new model which can easily be installed in the water, but it would have cost several grand more! So, I will wait until next haul out.

PYI 800-523-7558 <mpservice@pyiinc.com>

Good luck to you!

[Mr O]

Jerome Blakely
Max-Prop Service Manager
PYI Inc.
800-523-7558
Tel: (425) 355-3669
12532 Beverly Park Road
Lynnwood, WA 98087

[stormalong]

Originally Posted by DirtRdEarl

Do you have a plan B. I’ve disassembled my Max Prop Classic many times. Not a chance in ***** I would attempt this underwater. I want to hear the rest of the story. Good luck.

Same here. If it is a three blade it takes two people to put it back together. You don't want to drop a part in the mud below your boat. Those parts were hand fitted in the old days and you can't just order a part.

Bite the bullet and haul the boat.

[OloteleMtn]

There is no "boat yard" or haulout facilities here; I was a professional diver for years and am as good or better than anyone else here; I do not intend to lose any parts, but have spare screws, split pins anyway; I do not have other available options than what i am doing; I will put it back together in reverse order from disassembly, minus mucking up the screw head. Hope i did not miss any points of discussion, thanks for input.
ps the engine runs great when in neutral, gets full rpm without significant smoke; under load tied to dock and underway, black smoke appears and rpm is limited. No way to check fuel timing without removing engine due to access issues.

[OloteleMtn]

pss I have been in contact with PYI and they have been very helpful.

[LittleWing77]

OloteleMtn,

I am just saying, right here, right now that it is your BOUNDEN DUTY to let us know how it all worked out!!!

LittleWing77

[a64pilot]

Do not buy a compressor if you can help it, try to rent. Do you have shore power? Cause air tools use a tremendous amount of air which means a tiny little Hooka compressor won’t do it, not even close, and big ones won’t run off of a Honda or similar.
Your a diver? Take a primary reg and hook a long hose to it, there is your compressor.
Like this, the little tank to the right. Lots cheaper than buying a compressor. First stage should be set at about 150 PSI too.
Be prepared to drill that screw out and odds are the prop is going to need to go off to overhaul, based on other things condition. I’d start shopping for a fixed prop myself so that the Maxprop can go back on in the future when the boat is hauled.
I feel pretty sure it’s over pitched and that is where your low RPM and black smoke is coming from.

[OloteleMtn]

Ok, so here was Round #3 (yes there will be a Round #4)
Stopped by the shop, grabbed the 1/2 air impact gun and my air drill and a hose, headed down the hill to the hardware store. Found a Porter Cable oilless air compressor with a 6 gallon tank for $180....headed to the boat. Got everything rigged, tools down in a bucket, air impact gun with big screwdriver tip on, down I go. A short burst and the screw is moving, a little more and it is out. Separate the hub halves and put them in the bucket. Cone gear takes a little persuading, get it out....where are the pins? No pins, hmmmm.Nut doesn't look like it is supposed to, either. Poke around for a while and discover this is the old old style Max Prop, with a pinned nut. I have nothing that will address that, as the plan was for the newer old style Bouncier than the day before as well.
New plan....drop off an air tank for fill, come back tomorrow with an air chisel with pointy tip to get pin started out, then use pin punch to finish it the rest of the way, then get the prop nut off and pull the hub, continue with the cutlass bearing evolution.
Don't worry Miss Little Wing, I won't leave you hanging!
ps my dogs have been coming with me the last 3 days to the boat, they seem to be getting use to it.

[skipperpete]

That pin should be a loose sliding fit, it’s held laterally by the cone gear inner diameter so there’s no room for it to wander when the cone’s in place

[OloteleMtn]

That would be nice if it was, Cap'n, but it ain't.... otherwise i would be done already. I did try with a few things to get the pin to move, it wasn't having any. Murphy gets around......

[OloteleMtn]

A64, what kind of adapter fitting are you using to go from the dive rig fittings to the NPT fittings air hoses and tools use?

[Peterbreit]

I have a similar problem with the cutlass bearing on my 2000 Beneteau 461. When hauled the surveyor noticed the cutlass bearing coming out about 1 inch. When I looked at it I found one of the little (really LITTLE) set screws missing. I was able to push the cutlass bearing back in with my fingers! Question: The plastic tube holding the cutlass is very thin. There is just no good way to put a serious set screw in. Unforunately the yard reamed out the holes to fit a thicker screw but no I am SOL.
I would have put in the old little screws and put a SS hose clamp around it. We did put a donut shaped zinc on the shaft between the cutlass bearing and the Maxprop.
2.Problem The yard took the Maxprop off unnecessarily to get to the cutlass bearing. They had a hard time configuring the correct setting when assembling it. It looks ok to me but I don't know anything about Maxprop settings. I learned a lot fast.
The boat runs ok about 7knots at ~2400 rpm. But the tachometer never goes above 1400 rpm. What gives ?? I changed both fuel filters. When NOT under load (prop-transmission not engaged) it reeves up to 3500+. But under load shows no more then 1400rpm. I marked the "gas lever" at 2400 rpm. So I know I run actually 2400. But I cannot reeve it higher. Is this a tachometer problem? The Yanmar 4JH3TE engine gets the tachometer readings from the flywheel not the alternator. Or has it something to do with Maxprop? Or fuel filter or fuel pump?
Any help is very much appreciated.

[a64pilot]

Originally Posted by OloteleMtn

A64, what kind of adapter fitting are you using to go from the dive rig fittings to the NPT fittings air hoses and tools use?

Bought it at the Cave diving shop I used to use, it’s a SS quick connect fitting identical to what is normally used for air tools but as you know there is no standard there, many require only their nipple to fit.
https://www.caveadventurers.com/store/index.php
Probably have to call them.

Found a couple of ways to do it inexpensively this one seems to connect to your inflator hose
https://www.amazon.com/Scuba-Choice-...s%2C168&sr=8-6

Then this converts the Scuba threads on a hose to standard air hose 1/4” NPT, seems to be the least expensive and best way to me.
https://www.amazon.com/Scuba-Choice-...s%2C165&sr=8-1

[OloteleMtn]

Peter, i commented on your thread.....Just got off the phone with PYI to make sure i had all my ducks in a row before heading down to the boat today, they are very helpful.

[fstbttms]

A little late to the game but I have installed Max Props underwater many, many times. Don't hesitate to ask if you have questions.