Gap between propeller and custlass bearing

[andre]

Hi everybody, a couple of years ago I have installed a line cutter between my propeller and cutlass bearing. So the line cutter is very close of my cutlass bearing and I think is to close about 1/8. Since that time I hear a noise at different idle speed and I think because the line cutter is close there is restriction of water inside the cutlass but I'am not sure. For now I think if I install a flexing coupling between the transmission and my shaft I should have 1 inchs more. The flexing coupling would be a Isoflex. What do you think about my problem and about the Isoflex. Excuse my fault I'm learnig my English. Thank you very much. I know also that the gap between the propeller and the cutlass is supposed to be 1 time the diameter of the shaft but with the Isoflex it would be 2 inches.

[Ron Hill]

Andre : Don't know what to tell you?  The normal distance is 1 shaft diameter distance (C34 =1") between the rear of the strut and the front of the prop.
That is why I've never installed one!

Guess that you just have to make sure that there is at least 1/32" to 1/16" gap between the "cutter" and the strut - so water can flow thru.

A thought

[andre]

Hi Ron I had just place to install my line cutter and there is 1/16 gap between the cutter and strut. You say that's enough for the water?

[Ron Hill]

Andre : 1/16" should be enough gap to have the (cooling/lubricating) water flow thru. 

As far as your "noise" - just make sure that your shaft is centered inside the packing gland/stuffing box!!

Don't worry about your English as it's "a hell of a lot" better than our French!!

Good luck

[Jim Hardesty]

Andre,
You said you installed the line cutter a couple of seasons ago.  How is the cutlass bearing holding up?  If it's still tight I'd say it's getting enough water flowing. 
Jim

[andre]

Excuse me but what do you mean by holding up. If it is good again?

[Jim Hardesty]

Excuse me but what do you mean by holding up. If it is good again?

Andre,
That is to say, if the cutlass bearing is staying tight to the shaft, no wiggle, there is enough water flow and no problem.
Jim

[andre]

Ok thank you very much.

[Ron Hill]

Guys : If you haven't seen it before in the North East the lobster pots are tied with 3/8" or 1/2" nylon line.  Not like the 1/4" nylon crab pot line used in the Chesapeake Bay!!  The NE is a serious wrap!!

A thought 

[andre]

Yes that's why I have a line cutter. Est coast in the Maine is full of lobster line.  Tree time going under with my scuba bottle to remove the line. Most of the time my line cutter do thejob but there are excception.

[Bill Shreeves]

I'd be reluctant to clamp something on to the shaft 1/16" from the strut.  I've always assumed that the motor mounts would allow the drive train to flex forward while under initial load going forward and while hitting heavy seas

[andre]

And for you what's the minimum gap between strut and propeller is necessary. Thank. If I install a isoflex flexing coupling?

[LogoFreak]

Rule of thumb I've always followed is: distance from prop strut to propeller hub = shaft diameter. So for a Catalina 34 that's 1"

Whoever worked on my boat previously was a knuckle head and installed the cutlass bearing all wrong, either that or he gave up trying to install it all the way 

[Bill Shreeves]

And for you what's the minimum gap between strut and propeller is necessary. Thank. If I install a isoflex flexing coupling?

FYI, copied from another forum (https://www.meridianyachtowners.com/threads/line-cutters.372/):

That gap below is about 1", and the shiny part is where the shaft must move when underway so it would just about bottom out on the line cutter, which seems a bit too close?

ref attached pic