Nasty ticking coming home today - Maxum Boat Owners Club

Tommyfmu · 08-17-2009, 01:37 AM

We were heading home after a day at the beach on our 2400SCR this evening, 1999 sea water cooled 5.0L Merc, Alpha 1 Gen 2, and all was fine. All of a sudden, an awful sound occurred, somewhere from the engine area and immediately went into a horrendously loud ticking.

I immediately went into neutral, lifted the outdrive and the sound was coming right through the exhaust it sounded like. I then checked in the engine compartment to make sure the ticking wasn't coming from the engine itself, i.e. a rod hitting the lifter cover which could result in a thrown rod; it wasn't ... the sound was coming from somewhere between where the engine meets the outdrive. The oil pressure was normal, engine temp was normal, no loss of power, except the loud ticking sound increases with the rpms. The outdrive shifts into forward, neutral and reverse with no problem. We crept back to the marina under our own power, but at about 1200 RPMs for about 2 miles. I checked the engine and outdrive oil levels yesterday, no problem. At the start of the season I had the outdrive off, a new impeller, clean it all out and put it on for the season by a mechanic.

So any ideas what gives? I'm planning on calling in a mechanic but would be interested in any thoughts. Thanks, Tom.

seapuppy · 08-17-2009, 02:30 AM

sound's like the coupler or U-joint.....not good and it's gonna be expensive...

sorry..
SP :|

Tommyfmu · 08-17-2009, 03:16 AM

Thanks SP. Looking back through previous forum posts, I saw one from May 29, '07 that sounds like a very similar problem, and initial thought was U joint or coupling, but turned out to be that the upper shifting shaft seal leaked, allowing water into the bellows. Caused the gimble bearing to sieze to the shaft. He got a new shaft, bearing, and u-joints since it was in there.

If that turns out to be the same case here, any estimate of how much something like that may cost?

Regards, Tom.

Tommyfmu · 08-19-2009, 08:30 PM

Our boat was pulled yesterday, examined today and the outdrive upper unit is shot, gear teeth broken off and lots of little bits of metal all around and down into the lower unit probably too. Had to buy a remanufactured Alpha 1 gen 2 for 1300. and labor and hauling for 470.

A host of factors may have caused the failure, including 10 years old, but also may have been too much torque due to the 4 blade 15 x 16 alum. prop according to the outdrive specialist, as well as giving too much gas when starting off instead of more gradually bringing the rpm's up.

We are going back to the Maxum spec'd prop of 15 x 17 3 blade alum. (14 1/2 x 17 actually) to be safe even if we loose some top end speed from the 4 blade. Hopefully the info may help someone in the future to avoid this sort of thing. The good thing is a 1 day mid-week repair and we still get to use the boat for the remaining summer weekends

seapuppy · 08-19-2009, 08:36 PM

I had that happen to me back when we first got our 2455....top end broke some teeth...turns out it was from hitting a few chunks of wood....that will do it for sure...

the prop shouldn't have been an issue....

SP

irate:

Tommyfmu · 08-27-2009, 01:02 AM

Agreed Seapuppy that the prop shouldn't have been an issue, especially since Merc had the 4 blade spec'd as appropriate for a boat our size. The 4 blade got as high on the rpms as the 3 blade (both top out at about 4300). One big difference though is that we were getting engine overheat alarm with the 4 blade every time we ran over 3800 rpms and especially wot for more than 1/2 minute, whereas now with the 3 blade it runs no hotter than about 180 deg's at any rpms, even at wot for any amount of time, so at least we now know that our risers and mani's should be ok for a while. I read on here that engine temp shouldn't be affected by rpms from low through wot.

oneradride · 11-29-2009, 12:33 AM

The same thing can happen from throttling back to quickly. Never go from full speed to neutral quickly unless someone falls out or something. The back lash on the gears in the upper unit will destroy them if there is even a little too much play up there. Unfortunately I had to learn this from experience......

Argonaut · 12-02-2009, 12:03 PM

Quote:

Originally Posted by Tommyfmu

giving too much gas when starting off instead of more gradually bringing the rpm's up.

Thought that was the only way to start off

SilveradoSS · 12-04-2009, 02:47 AM

Have to agree, I run the river here a lot and idle to WOT is the way we run and no problems. We have a lot of bridges that are no wake so stop start is the program. Drive it like you stole it is my motto.

Argonaut · 12-04-2009, 02:29 PM

Quote:

Originally Posted by SilveradoSS

Have to agree, I run the river here a lot and idle to WOT is the way we run and no problems. We have a lot of bridges that are no wake so stop start is the program. Drive it like you stole it is my motto.

> Drive it like you stole it is my motto

I think I'll use this as my motto as well