Duo prop thingy

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Sailorsam101

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Last night my targa finally came out of the water for me to see whats what for the first time.

I have a 1.95 drive unit..i believe.

All looked as i would have expected apart from this. The right hand rear prop could move forwards and backwards about 5mm on the shaft..all the others were rock solid.

Not good i thought so lets take the rear props off and see what i can see.

Both came off as expected but..and here is the but...there is nothing in between both props apart from the retainer nut for the front prop. I was expecting to see a bearing cover but nothing...the shaft seal is there exposed for all to see.

On the right hand prop again no bearing cover but it does have a small thrust washer.

Now I've looked at drawings for these for hours last night and i'm not sure what i am meant to have but i knwo that something is not right. Some say i should have a rubber part to the front of each prop..well i don't on either.

Also both end cones do not have any washers or anything that the drawings might suggest.

Also i could not see any reason for the right hand prop moving.

I'll get somebody out ASAP to have a look as i don't knwo what it should look like.

Any ideas?

Also my props look OK but should i get them blasted and cleaned up before i spray them?
 
On mine, after removing the rear prop the next item was the large nut holding the front prop. There is a thrust washer at the front of the rear prop that usually comes away with the prop as it is recessed into the front surface. I don't think there should be any play fore and aft, maybe the cone was not tightened properly? I had one spin off once and the prop went with it presumably whilst reversing.
No washers in front of the cone on mine though I have seen diagrams with different arrangements.
When you refit the cone (very tight) be careful tightening the lock nut, it is easy to shear. There is a torque setting of 16ftlb and it isn't as tight as you might expect.
Can you move the rear prop shaft back and forth, that way you know if the movement is prop on the shaft or the shaft itself.
 
In the prop nearest the cone, there should be a plain thrust washer.
In the prop closest to the drive, there should be what looks like a thrust washer with teeth.

You're correct that the shaft seals look a bit exposed ... but that's the way it is.
 
FP is correct. Make sure that both thrust washers are present when you replace the props as , if not, it can get expensive! (dont ask how I know)
Sometimes when removing props , the washers stay in the recesses on the prop , other times they stay on the shafts.
 
Well folks..i had another good long look at the props last night and found the following..

Left props are newish...very good condition with no damage at all. The thrust washer between them is not there are as never been by looking at the shaft.

Right props are older with some wear but still look fine to me. The thrust washer is there and fast on the shaft.

I've got a new washer on order and will get this on the left hand props.

But the issue i now have is are my props the same both sides. The left are A7's but the right has lost it's marking. Do i bite the bullet and get a new right had set...but where from.

I'll try and get some pics up here later.
 
It's unlikely that different prop sizes will have been fitted to different outdrives ... the fact that your boat went around in circles all the time would be a bit of a clue.
If the markings have worn off, you could measure the distance along the central hub from the end of the prop, to where the blade root joins the hub.
 
Well the plot thickens.

With the rudder indicator in the center the boat does turn to starboard...not much but it does do it. I have to have the indicator just off to the right for the boat to go straight.

Also one engine revs 200 rpm more than the other at WOT..can't remember which.

Would a nice new pair of props on one side and an older worn pair on the other lead to either of the above?
 
The prop markings dont get worn out, they are firmly engraved. If they are gone someone have taken them off which would leave marks and if so you probably have a set off odd props.
Good advice measuring as proposed earlier but if someone has been consiously messing with the markings then I would get them to a good prop guy and have them check and make sure they are well centred, the hub is set right and overall in balance.
 
Remember the indicator is just a piece of wire attached to the drive so it is adjustable. The accuracy of centre is simply how well it was set up.

Sailorsam101 said:
Well the plot thickens.

With the rudder indicator in the center the boat does turn to starboard...not much but it does do it. I have to have the indicator just off to the right for the boat to go straight.

Also one engine revs 200 rpm more than the other at WOT..can't remember which.

Would a nice new pair of props on one side and an older worn pair on the other lead to either of the above?
Click to expand...
 
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