folding prop. a problem?

[jason -and the arguenauts]

my folder makes a real clunk as I put the boat into gear. whats more , if the boat is going forward and I put the engine into reverse, there is a considerable vibration until the speed gets high enough to fully open the prop.

is this normal?

 

[savageseadog]

You may find that owing to corrosion the teeth at the root of the blades no longer mesh properly.

PS I have as brand new folding saildrive prop for sale.

 

[jason -and the arguenauts]

Thanks. They seemed to mesh OK when I had the boat out of the water.

Mine is non saildrive. Does your prop have any sort of plastic / rubber bump stop on it to prevent the loud clunk when engaging?

 

[johnalison]

Depending on the type of prop, a clunk on engaging "ahead" is quite normal; in fact I get worried if it doesn't, which suggests the teeth are fouling.

Some folders may not open well in reverse, especially if foul and a good blast of astern should do the trick. The Volvo doesn't seem bad for this and although the teeth are greased any barnacles in the way soon get crushed.

 

[savageseadog]

Thanks. They seemed to mesh OK when I had the boat out of the water.

Mine is non saildrive. Does your prop have any sort of plastic / rubber bump stop on it to prevent the loud clunk when engaging?

No.

The folding action will seem OK but you have to work the blades against each other at various angles to make sure. Any general looseness could make the prop suspect.

 

[jason -and the arguenauts]

There certainly is some general looseness / wear - the prop is 12 years old.

 

[cagey]

Prop

My folding prop is 18 months old (Gori) and was only replaced because of new engine and gearbox. Both give a distinct clunk when engaging forward which I find nice and reasurring telling me the blades are opened fully as for astern I get shuddering and vibration which I put down to the enormous stresses on drive train, where possible I wash off as much speed as poss or gently engage astern and slowly build up revs.
As for looseness on my original gori I had larger pins fitted with the relevant holes in hub and blades drilled slightly off center , this was done by an engineer who knew what he was doing, didnt cost a lot of money but the gain was zero.

 

[webcraft]

I think it is normal

.
I think the clunk is normal - our 2-bladed folder does it.

- W