Hit something with lag and now only low speed, what happened?

so was going around 14 mph on my boat (87 Four Winns) with the 3.0 Mercrusier, middle of lake of course, and felt a thud, not very big one, but enough to know. After that boat would not go over 9 mph and had a shake and sounded horrible. Did stop and check what i could see and everything was normal and could not tell what was wrong and was a long way from dock, so kept going along at slow speed. It did have a minor shake. every once I would try to get a little more speed, usually didn't work. One time it did and was getting normal speed (30) for a while until again it would not go over 9. Made my way to dock, and inspected, no visible damage to prop or lower unit anywhere. It was taking on a lot of water when engine was in trailer mode while waiting for truck to come with trailer. Had to run the pump twice even.

Anyone out there want to take a guess what may have happened and what I should look for to fix? I want to try it on the muffs to maybe see or hear more?

Re: Hit something with lag and now only low speed, what happened?

Oh and it's a 5 blade stainless steel prop, like stated no damage.

Re: Hit something with lag and now only low speed, what happened?

FourWinns86 said:

Oh and it's a 5 blade stainless steel prop, like stated no damage.

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The loss of forward speed sounds like the prop hub has spun. Prop can be re-hubbed by a prop shop and some even have a user replacable hub on them. I would guess a new style 5 blade is one of them. Other possible is the engine coupler, but prop hub usually goes first. Pull prop off and, on the muffs, see if the vibration goes away when run in gear. Also check that the prop shaft is running straight and true, not bent. Problem w/ S/S props is that they aren't as forgiving, by breaking off, as aluminum, which breaks before drive damage occurs, usually. S/S props can transfer shock to the drive pretty easily when striking something where the aluminum will snap off a blade, absorbing most of the shock before it goes to the drive.

The vibration could be linked to that or lots of things much worse. The taking on water seems to be the more sinister problem, which would suggest gimbal / bellows / transom mount knocked askew problems. Those are the biggies....

Re: Hit something with lag and now only low speed, what happened?

Thanks for the reply, if it was the prop hub, does that make sense that it would have only slow speed then all of sudden be fine for a while, then back to only slow speeds?

As for water, I had the gimbal and bellows replaced this year already and it is still taking on water. When the engine was up and boat in water, it was flowing in right at the bottom of engine I stuck my hand under and at the bottom could feel it, it was like a small waterfall. But when engine was back down it wasn't as fast. Is that the transom?

Re: Hit something with lag and now only low speed, what happened?

FourWinns86 said:

Thanks for the reply, if it was the prop hub, does that make sense that it would have only slow speed then all of sudden be fine for a while, then back to only slow speeds?

As for water, I had the gimbal and bellows replaced this year already and it is still taking on water. When the engine was up and boat in water, it was flowing in right at the bottom of engine I stuck my hand under and at the bottom could feel it, it was like a small waterfall. But when engine was back down it wasn't as fast. Is that the transom?

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Would need to see it first hand to comment. Tough call, but may be time for professional help on that on. Water coming in (waterfall, as you said) is real bad. Lots of places it can come in back there, but "at bottom of engine" sounds like transome plate seal, exhaust port / flange, drive bellows or even shift bellows maybe. Too many possibilities.

Re: Hit something with lag and now only low speed, what happened?

the 'waterfall' is only when engine is fully up and boat is in water. Takes on some water with engine down, not a waterfall though and yes I know it's bad, but do have a pump that works. For now I want to get the prop issue fixed and hopefully with some help on here I can. Today on a stress free inspection I did notice some damage. The prop has a minor dent, can be grinded out or just left? And the spindle that holds the nut in place has moved from the impact. So I need to find a way to left that spindle up and get the nut off and inspect the shaft and hub right?

I will try to post pics to make things easier. BTW what size the prob bolt? I have a breaker bar just need to get the correct socket

Re: Hit something with lag and now only low speed, what happened?

My nut is 1 1/16". I have a socket on my torque wrench and also a plastic wrench I keep in the boat for emergencies and it floats!

Re: Hit something with lag and now only low speed, what happened?

Need to get a clear understanding of your "terms". A spindle is a shaft.... If the spindle that the prop is on has moved, then it is bent. Only thing I see in your photo (top one) is the lockwasher, which looks normal (tabs engaged at three places, good). Now...about that spindle...
When you freewheel your prop (spin by hand), do you notice any runout? Prop looks fixable (dent wise)... Still need to rule out the spun hub, which you can do by putting marks on the hub nut/shaft and the prop, getting in the water, running for a bit, then checking to see if the marks don't line up anymore. Good luck!

Re: Hit something with lag and now only low speed, what happened?

yeah sorry not 100% familiar with all the terms. I was calling the spindle the lock washer. I thought all 6 tabs should have been engaged in place, but if it's only 3 then I guess it's right. Not sure what you mean buy noticing any runout? When I spin the prop with my hand in either direction it spins freely but there is a slight wobble noise. There is also some movement when I pull on the prop up and down much like when a wheel bearing is bad. Could someone put the marks on the hub nut/shaft and run it on the muffs and check for movement? or does it need to be under load in the water?

Thanks to everyone so far for your help! I think my nut also is 1"1/16, or course I have 1" and 1" 1/4 in my tool box but not the one I need.

Re: Hit something with lag and now only low speed, what happened?

FourWinns86 said:

yeah sorry not 100% familiar with all the terms. I was calling the spindle the lock washer. I thought all 6 tabs should have been engaged in place, but if it's only 3 then I guess it's right. Not sure what you mean buy noticing any runout? When I spin the prop with my hand in either direction it spins freely but there is a slight wobble noise. There is also some movement when I pull on the prop up and down much like when a wheel bearing is bad. Could someone put the marks on the hub nut/shaft and run it on the muffs and check for movement? or does it need to be under load in the water?

Thanks to everyone so far for your help! I think my nut also is 1"1/16, or course I have 1" and 1" 1/4 in my tool box but not the one I need.

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The "runout" means when the splined prop shaft is turned by hand, the shaft should be perfectly straight, no wobble at all. This is normally checked by placing a dial indicator against the shaft and thurning the shaft by hand. There should be little to no movement of the dial indicator.

The prop looks easily repairable by a prop shop. Looks like it hit more than a log though, something much harder. A hard hit like that would indicate a check of the drive may be in order. And I bet the hub is spun. When you have the prop repaired, just have it re-hubbed too. They do go bad with age, sometimes, too.

PS: You'll not get all the tabs of the lock washer to engage the slots. They are designed slightly "offset" to ensure at least some will engage slots in any position. Should have 3 engaged. Any dings in a S/S prop will effect performance of the prop, sometimes quite badly with even little dings.

Water coming in as you described, only with drive fully trimmed up, would make me suspect the drive shaft bellows. That is where I would start. Trimmed all the way up like that will stress the bellows and if it is split, the split will widen and will let in much more water.
I would pull the drive off and see if there is water / nasty water logged brown grease muck in there. If there is, then I would consider new U-joints and deffinately a bellows.

Re: Hit something with lag and now only low speed, what happened?

Fxdwgi has you on the right path to fix your problem. Just to help you with your boat terms, you raise and lower the out drive not the engine We were all new at this at one time so I'm not pickin on ya What model Four Winns you have there?

Re: Hit something with lag and now only low speed, what happened?

any water coming in is BAD. when was the last time the bellows were replaced?

Re: Hit something with lag and now only low speed, what happened?

Thanks 04fxdwgi. As far as I can tell it turns straight, like I said before I do hear a slight noise when I turn it. I tried my neighbors prop on his boat and I don't hear any noise. Also when I pull the prop up and down it has some movement, not sure if that is normal as I have never pulled my prop before up and down. Today I will take the prop off and check the hub and post pics. I am hoping it's just the hub and I have already called the dealer about the hub kit. Changing the hub seems like an easy thing that anyone can do themselves.

What model Four Winns you have there?

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1986 Freedom I, it's my first boat (I also had a sea-doo too). I wanted an older boat so I could learn things like this first.

Scott Danforth said:

any water coming in is BAD. when was the last time the bellows were replaced?

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I had the bellows, u joint and gimbal bearing done this spring. Along with the impeller kit. What tells me that it may be a bigger issue with the water???

Re: Hit something with lag and now only low speed, what happened?

FourWinns86 said:

I had the bellows, u joint and gimbal bearing done this spring. Along with the impeller kit. What tells me that it may be a bigger issue with the water???

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Sadly, even "newly installed" bellows can fail due to any number of issues (may have even not been installed properly and can give out when stressed to the trailered position.) Shoudl be easy enough to inspect when you manipulate the drive up/down/left/right. That will rule out those issues. Still need to figure out why you get a waterfall in the boat when the drive is trailered up. Very bad!

Re: Hit something with lag and now only low speed, what happened?

My thoughts!

Get ya a big cheapo ( harbor Freight ) cresent wrench for your prop nut.... Take prop off and inspect the hub...... then check your prop shaft (Spindle) for movement AKA- runout- ...up and down and side to side movement, if good then .... slap the muffs on and check for vibration, if good then take prop to a shop and have fixed.

Now for the water fall. Get the prop problem fixed first... then if good .....take it back to the person that put your bellows and ect... on this spring and tell them its leaking water.......and see what they come up with?

I wouldnt tell them about your prop problem at first... my feeling is if you say it they will blame you and not fix it free.

Added note: Shouldnt run the boat with the drive in trailer position.

Just a thought! Good luck!

Re: Hit something with lag and now only low speed, what happened?

Guys this site is the best! Thank you all for adding some bright light to a bad situation. Here's my update: Took off prop, the prop shaft appears to be straight to the naked eye. Ran boat on muffs with prop off and was no vibration. Wasn't sure if I can open it up on muffs, so did not throttle too much. Took prop with hub to local shop. One look they agreed the hub was done, now for my luck it's a built in hub and around here they don't have anyone who will re built it. so I have a $900.00 s/s 5 blade prop with a blown hub for sale now... Bought a new hub kit and new 4 blade prop (aluminum).

Going to install everything today, from what I understand I won't be able to test the prop shaft until it's under load in the water which I will get to next weekend hopefully. Then if I still have a vibration I need a new prop shaft, which then I think the boat and I will part ways (unless there is a way to do without spending big bucks). But if I have no vibration, then I will focus on water issue.

Quick question, on that style of boat could the water coming in be from a rotten transom?

Re: Hit something with lag and now only low speed, what happened?

Quick question, on that style of boat could the water coming in be from a rotten transom?

YES..... It could....
But as you described..... when in trailer position it flows more water..... if it were the transom i would think it would be the same no matter what position the drive is in. When you trim up it stretches the bellows and can open up a hole!

Take a peek at your bellows tonite... turn drive by hand left and right ( Trim up and down) look with a flashlight and see if you can spot a rip or tear....check the little clamp at the end of the shift cable bellows.

$900.00 prop....Whew

Good Luck!

Re: Hit something with lag and now only low speed, what happened?

I think it's a bellows problem from what you describe.

Re: Hit something with lag and now only low speed, what happened?

do a google search on prop shops, there are still a few that re-hub, however you will have to send it in. my last quote was $150 from a place in Washington.

yes, a rotten transom will cause a leak, so will a bad bellows, so will a bad transom shield (possibly broken from when you whacked something)

your best bet is to put it in the water, and get back there and look to see where the water is coming in. then pull it out and repair the issue.