Max Prop v1 - locking collar

[briblack]

Here's a photo I received from Fred Hutchinson at PYI, when I was working on this issue on my boat. There's two half circles, one on the hub and one on the collar. When aligned, they're tapped for a metric 4 x .7 or 5 x .8 screw. Grub screw or similar

[BigAl.NZ]

Thanks to all here. You are completely correct the support at PYI is outstanding, and I would by there products again in a heartbeat for the support alone.

As it turns out we have a MaxProp VP. A pin inside the unit must have sheared as the locking collar does not (at present) lock.

We are putting in a temporary fix which will be a temporary locking pin fixing the pitch.

Its a Hood 38 with a 48 HP Perkins 4108, 2:1 reduction on 18" prop, so we think the pitch should be between 9 and 11 inches. I am favoring more towards the 9" at this stage (unless anyone knows better).

Al

[BigAl.NZ]

Just to add to my comments about PYI. They really were great. The comments form on there website got a reply almost right away. They were happy to tell me about a temporary fix for the problem, and were able to communicate via phone and even sent a short video showing how to do the repair.

Needless to say I have not brought any parts from them yet as we are doing the repair, but if I ever need a prop I am going to PYI, even if only from a service and support point of view (which is truly outstanding).

I wish all companies had this sort of culture. I owe them a few beers next time I am in WA.

[lancelot9898]

Originally Posted by BigAl.NZ

Its a Hood 38 with a 48 HP Perkins 4108, 2:1 reduction on 18" prop, so we think the pitch should be between 9 and 11 inches. I am favoring more towards the 9" at this stage (unless anyone knows better).

Al

I've had my max prop since 1985 when the boat was brand new and it is a great prop. I too have a 4108 Perkins with a tranny of 2.1: 1 reduction on a 17 inch prop. The boat is a 37 foot Tayana with a loaded displacement of close to 30000 pounds. The fix prop that came with the boat was a 17 by 11 inch pitch which I never used and so the max prop was used from the get go. At first I set the pitch close to that 11 inches, but did not think it gave good speed so I increased the pitch to the next higher setting. My prop does not have the collar and every 3 years when I hauled the boat I needed to apply grease which I needed to completed take the prop apart. Several years ago I got the zirc fittings so disassembly is no longer required unless I want to change that pitch. I cruise at 6 plus knots at 2500 rpm and wot is at 3000rpm. I'm a little over propped but the Perkins is doing fine after 35 years so no complaints. You have the 18 inch so your mileage may vary. PYI is a great company.

[BigAl.NZ]

As a conclusion to this thread. We installed the temporary fix suggested by PYI and now have our MaxProp VP locked at 16 degrees.

Perhaps not surprisingly the engine (Perkins 4.108) now develops much higher RPM (about 3600 max) and we have about 2 extra knots of boat speed!!! Woohoo.

I presume before the prop was hitting its max pitch which was something like 28 degrees, making us very slow and the motor work very hard.

Thanks for everones input.