Folding Prop Reverse No Traction

[FinnON]

Hi all,
I just got a sigma 33 with a beta marine 20hp, the boat has a twin blade folding prop and yesterday when trying to manoeuvre in the marina I had 0 manoeuvrability while in reverse, it went into reverse without issue. All sounded good and has good traction in forward but couldn't turn at all in reverse and was at the winds mercy.

Anyone have any ideas how if something might be wrong or ways I can improve my manoeuvrability as I'm in a tight marina with strong wind and tides.

Thank you for any help or pointers.

[tkeithlu]

It's not clear to me just what the situation is. You say it goes into reverse, but no traction. Does that mean no reverse force or no reverse steering? There could be several situations:

In reverse, but prop spins without traction, and you checked that the shaft is turning: the folding prop has not gone into reverse.

In reverse, but the shaft is not turning: You are not really in reverse, and need to look at the control cable adjustment.

In reverse, prop is pulling, but no steering: That is really normal. Steering a boat in reverse is very tricky, and particularly if working against a wind.

So, clarify, and then maybe we can solve the problem together.

[Pete7]

The blades may not be opening up fully on the prop in reverse. There are a series of videos like this one which show some odd problems.

First thought then is to clean the prop and in particular the gear teeth which mesh the blades.

Nice boat btw, built by Marine Projects and many of the fittings on yours are naturally identical on mine.

Pete

https://www.youtube.com/watch?v=3_adsflxy8g

[Gary Mc]

It could just be your prop. There is a very common make of folding prop that has almost no drive in reverse, a little but not much. I had one then bought a Gori which is a much better folding prop.

[dfelsent]

I had two boats with two blades Martec folders. Raced them.
With those props reverse IS there. But you need to rev the engine when in reverse to find it.
Revving increases the centrifugal force and opens the blades. You get some but not a lot of power.
As others have mentioned backing sailboats is funky until you learn how. The two blades Martecs I’ve used don’t make that easier.

I knew and accepted this and used them happily for a total of over twenty years.
Reliable and low sailing drag.

[FinnON]

Apologies, I mean that there is no steering when in reverse. I'm going to confirm that the blades are opening as expected etc later this week.

[ChrisJHC]

You typically need to be moving at a couple of knots in reverse before you get any steering from the rudder.

I keep the rudder centred until I’ve got some speed up before trying to steer in reverse.

[Apollo366]

I'm 2+ yrs into a FlexoFold prop, I'd heard all the horror stories about the folders not "getting" a bite till 1/4 throttle & half a minute of waiting.

I am very happy to report that my FlexOFold engages astern as soon as shifted into rev gear at ideal, just like the fwd gear.

Your video show a lot of weed growth on the outside of the folding prop, yes this means there is a lot of growth on the inside too, esp hard barnacles. Having a diver clean both inside & outside of the folding mechanism until it opens with only a pinky finger of force is what is needed.

I'm quite confident that then the prop will unfold in rev & start astern motion at very low rpm will happen unless it is a very old design that did have problems opening and biting at low rev rpm.

Hope this helps,

Apollo Wayne
Waiting to go cruising again!

[Cheechako]

Some folders are useless especially in reverse.... Otherwise, I wonder if it's opening?

[JPA Cate]

You have to have water moving over the rudder to turn the boat. When we had our two blade folding prop on our previous boat, I found it took about double the rpm in fwd to get to steerage way in reverse. I took to giving it a lot more in reverse, to get water flow, then backing off, once I had steerage way.

Obviously, a thorough cleaning will help with the situation. It is lack of steerage way that is the problem, because it was steering okay in fwd, with enough way on.

Ann

[chasfgr]

Most gearboxes offer a considerably lower gearing in reverse, this means that opening the prop, in reverse, usually means a lot ov revs and time are needed.
Ally that to the need for a considerable speed through the water, before the rudder bites and you have the reason.
I was very glad when my folding prop, dropped a blade and I replaced it with a 3-blade Autoprop - it still needs much more way on to work than in forward, but it does work.

[Enialb2]

Originally Posted by dfelsent

I had two boats with two blades Martec folders. Raced them.
With those props reverse IS there. But you need to rev the engine when in reverse to find it.
Revving increases the centrifugal force and opens the blades. You get some but not a lot of power.
As others have mentioned backing sailboats is funky until you learn how. The two blades Martecs I’ve used don’t make that easier.

I knew and accepted this and used them happily for a total of over twenty years.
Reliable and low sailing drag.

Same here. After learning to dock on fixed bladed prop cruising boats, my first boat is a 2 blade folding martec, and compared to a fixed blade, it has no bite in reverse. Takes lots of throttle in reverse for what feels like ages, just to slow the boat. Great for racing though! Perhaps this is what you’re experiencing.

[MicHughV]

remove the folding prop....install a Max prop...problem solved....many used one's available...

[FinnON]

Hi all, Just a small update. I confirmed last night that the prop is opening fully in both forward and reverse. It closes slow enough but it does close fully. It sounds like it could just need more revs in reverse to gain some steerage. I will be doing some testing tomorrow night to see if this is the case.

Thank you all for your help and advice.

[MikeHoncho]

all inboards, regardless of the prop, have poor steerage in reverse compared to OB's or stern drives