Loose prop?

[graphicpunk]

So this past weekend I bought a brand new prop for my '87 Merc 90hp and tonight I tried it out for the first time. I wasn't sure how tight to get it because the guy at the marina was saying they are good to 75lbs of torque. Not sure how to figure that out but I just tightened it down until it felt tight. I didn't tighten it down until I couldn't tighten anymore. Anyway took it out and the first hole shot took longer and felt weaker than my old beat up SS prop I replaced. The next hole shot wasn't as bad. Anyway we picked up some family and just slow cruised it around the lake for a bit before it started to rain. So with 4 people on my boat it tops out like 35mph but I gunned it and it was up and out of the water like a champ! I slowed it down a bit but it seemed like we could go a lot faster than 35mph. Anyway after we dropped them off I tried another hole shot with just me and my wife and it was up and out like nobodies business. So I was thinking maybe it just needed to be broken in a bit? Anyway got it out of the water and of course I did the inspection and I noticed there was some play. The prop was no longer snug and I could move it a bit back and forth. The nut, holding everything on was tight and wasn't moving. So I am wondering if this is how it is supposed to be because I have heard it is good to have some play on certain motors.

So here is a short video I took of it let me know if this is good or bad because the performance was showing near the end of the night.
http://www.youtube.com/watch?v=yknm7IAUtw0&feature=plcp

Thanks!

 

[kidafa]

Re: Loose prop?

Im surprised that prop isn't on the bottom of the lake!

TOO LOOSE FOR SURE

 

[scott8058]

Re: Loose prop?

I agree, i have a little bit of movement but not like that and that lock washer should be tight i would imagine. Maybe the nut is tight because its screwed on crooked, im no expert but thats my guess......good luck!

 

[jestor68]

Re: Loose prop?

Are you sure that you put the thrust washer on(in front of the prop)?

Regardless, the prop is loose. The nut should be torqued to 50-55 ft-lbs.

You need to block the prop with a piece of 2x4(between the prop and AV plate) in order to properly tighten the nut.

Don't forget to bend 3 of the locking tabs on the washer down into the groves on the washer.

If you google "changing a propeller", you'll find a number of videos on how to properly do it. The Solas website also has a video on changing their props.

 

[WIMUSKY]

Re: Loose prop?

I agree, i have a little bit of movement but not like that and that lock washer should be tight i would imagine. Maybe the nut is tight because its screwed on crooked, im no expert but thats my guess......good luck!

Or, it's a nylon lock nut. But, yeah, it's way too loose.....

 

[graphicpunk]

Re: Loose prop?

Thanks all! That is why I posted to see if that was too loose or not. Now I am feeling thankful it didn't come off! I know how to put the prop on it was just the tightening that I wasn't sure about. I guess I didn't get it tight enough the first time. Time to get a torque wrench!

 

[jkust]

Re: Loose prop?

I put on a new prop and hub earlier this season. I've done it many times and change props depending on where I boat and so it is second nature to me. During the initial ride my speedo started acting really weird and low and behold the nylon nut on the hub kit loosened itself which is beyond me. I didn't torque it enough but there were no other symptoms. Regardless, grab on to the prop and see how much it pulls up along the prop shaft. For me it was pretty obvious as the nut had gone up many threads and the prop pulled up a lot. For me this was the biggest boating error I've ever made. I carry an extra prop, prop shaft lube, 2x4, large crescent and a floating prop wrench just in case.

 

[jestor68]

Re: Loose prop?

Make certain the washer is fully seated into the prop hub, engaging the splines on the end of the prop shaft(it must not turn). Unless the washer is engaging the splines, you haven't locked anything. The whole assembly can come loose.