Stuck! Need advice ASAP 7.4 motor knock- need to get home!

Lake Erie Boater said:
Dripless shaft seals are cooled with water that is pumped to them from the engines raw water circuit. If the engine is not running, then you are not cooling the shaft seal and will burn it out. Check to see if by chance your seals are "cross connected". It's simply a line with T fittings between both shaft seals. If you have this, then both seals will get water from either one running engine. My boat was not cross connected and my surveyor pointed that out. I had them cross connected for just this reason. From what I have learned, DON'T allow that prop to free spin unless you want to replace the dripless seal. This would require removing the shaft to do so and will get expensive with haul out etc. etc. If your's aren't cross connected, then yes, the vice grip, or a pipe wrench tightened against the shaft and held against the stringer is in order.
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thanks Randy, mine will be cross connected but they are not so I will secure that shaft
 
my3sons said:
Russ, Sorry to hear of your problem. If you have a ZF hurth 630 v drive, allowing the shaft to "freewheel" should not damage the transmission. If you do not have cooling/lubricating water crossover from the running engine, you may do damage to the shaft and /or seal by allowing it to freewheel. In that case you have to tie it off to prevent the shaft from turning. You may be able to get an adjustable wrench on the coupling nut and secure it against a stringer with a good amount of duct tape or what ever you have handy.
I would also close the seacock to that motor before towing or running on one engine, to eliminate the possibility of forcing water through the sea water side of your cooling system and flooding the manifolds. (leave a note to that effect next to your ignition switch)
Hope your up and running soon.
Good luck
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Mark, thank you we did just that with the shaft but did not think of the seacock, good idea- thanks
 
fwebster said:
There are 2 potential problems with a free-wheeling shaft: One is the dripless seal gets no lubrication at all and the seal design used on Sea Rays is a Delrin collar or seal body that requires water as a cooling agent and lubricant. You might run a few miles at idle, but 19 miles probably will mean replacing the shaft seal. The only exception here is if your boat has cross-over cooling and you can tell that by checking to see if there are one or 2 hose barbs on the seal.....2 means you have cross-over cooling and you can run home on one engine. However, the second problem is a little more dire in the consequences department: SOME transmissions develop internal hydraulic pressure when the shafts free-wheel and turns the output shaft in the transmission. That will partially but not completely engage the clutch pack and can burn up the transmission clutches, so the problem isn't no oil flow or a lack of lubrication, but too much oil flow. Some transmission design can free-wheel without damage and I think the ZF-Hurth 600 and 800 series later replaced by the 60-80 or 65-85 series identifiers are ok to run free-wheeling. I don't know about other brands and Sea Ray has used Hurth, ZF, Borg Warner, Velvet Drive and Twin Disc brands at different times.

The safest thing to do is to tie off the shaft and go slow. Vice grips aren't going to have the holding power to do it. You need either a pipe wrench on the shaft/coupler resting against a stringer or a large adjustable wrench on the shaft nut and resting against a stringer or tied off in some manner. You can also tie off the dead shaft/prop with a line.

Also, from your description of your engine problem, you most likely have a broken rocker arm, bent push rod or a bent valve.

Good luck with it..............
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Thanks Frank, with Alex's help that's exactly what we did. I return on Sunday so I will find out soon. The problems you mentioned- are they big fixes? Idea of cost and time? Thanks again
 
Steve, I don't go back until Sunday- no sense in wasting a vacation!

Thanks Todd, I am and will continue to follow your advice!

The bill, I mean mechanic is queued up for my return and will diagnose it next week.

Thanks to Alex and Ron who are here to help and all that posted a response I now have a locked shaft and closed seacock to prevent further damage in preparation for the return 19 miles on Sunday. It will be interesting to see how she maneuvers with one motor, not looking forward to it. I am also not looking forward to the fix but thanks to you all damage has been minimized. I will post progress and outcome- thanks again.
 
You'll be OK getting there.

When it comes time to dock, you'll probably need calm conditions and some help on the dock along with a long line or two so they can guide you in.

You don't want to add a swim platform repair to the bill.
 
It's somewhat hard to suggest this because some people are better at initially diagnosing issues and understanding the severity of the repair, but it may be possible to just start the other motor when you get close to the dock in order to get in safely.

Doug
 
That's what sea tow is for. Just call ahead and let them know you'll need help getting into the marina and slip.
 
Russ,

I just got back from vacation, and read of your problems. I'll try to be brief:

1 - Top end knocks are usually caused by bent pushrods, broken rocker arms, broken valve tips, bent valves, etc. In a nutshell, you have a valvetrain problem, and hopefully the damage is confined to just that. If any debris from these broken / damaged parts has found its way into your oil pan, through the oil drainback holes, then that is not a good thing. Your intake valve covers, and intake manifold, will have to be removed, at a minimum, to inspect the damage. Don't be tempted to just stick in a new pushrod and rocker arm, and start the engine. There could be debris on the lifter valley, or a damaged lifter. Removing the manifold is the only way to know.

2 - There is a reason the valvetrain was damaged. Something caused the failure. It is possible that a rocker arm failed due to simple fatigue or wear, but this is unlikely. It is more likely that some definable cause prompted the failure. If this underlying condition is not identified, and rectified, then another failure may occur. A good mechanic should be able to piece together the chain of events, and identify the problem.

3 - Lock your shaft. The forward motion of the boat will induce shaft rotation, and operating the shaft seal without engine supplied cooling/lubricating water may cause a seal and bearing failure within the seal housing.

Send me a PM when you get back, and I may be able to supply more than just advice. Lots of spare parts in the shop!!!

Dale
 
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Russ it was great meeting you and your wife... I liked Mike's the idea of calling sea tow... We got beat up coming home yesterday in the Ocean with two engines... Fortunately I was following in Alex's wake... It took us 5 hours from the Shinacock to the Manesquan inlet... My youngest daughter threw us twice... Funny thing, both Alex and I had our toilet seat covers come off... The boat did fine, but the crew was beat... Hope you made it back all safe and sound... We ordered a new dinghy from your friends at Defender today... It will arrive tomorrow... It cost less than than a tank of gas, but then most things do....
 
Thanks Dale, I appreciate that! Rod, sorry to hear about the rough ride- Alex had sent me texts yesterday, that's a bummer.

Update- my trip back was slow, strange and fairly uneventful. We left Block at 7:30 and arrived at our slip by 11am. We traveled at about 7.5 knots at 2100 rpm burning about 9 gallons an hour. She is awkward under one motor but became predictable and fairly easy to handle. I had several folks to support my arrival at the dock and all went smooth the only concern was timing the opening of the railroad bridge but it worked out.

After inspecting the bilge I found that the shaft nut that had been secured by a wrench had in fact spun off, shearing the cotter pin off. When this happened I am not sure, so I cannot tell how long the shaft had been spinning. I can say it felt cool to the touch and so did the water within the dripless seal. I will find out in the next couple days, I added it to the mechanics list of things to check. So if anyone ever finds themselves in this position just tie a line around the prop to be safe. I actually had one then decided the wrench would be enough and removed it- lesson learned.
I will update as soon as I know more.
 
Russ glad to hear you made home safely... Now I hope your repair costs are minimal... thanks again for introducing us to Block.... Next year when all my Jersey Shore friends show up you may have to deny knowing me...
 
rcknecht said:
Russ glad to hear you made home safely... Now I hope your repair costs are minimal... thanks again for introducing us to Block.... Next year when all my Jersey Shore friends show up you may have to deny knowing me...
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Thanks Rod. I am glad you guys liked Block, it's one of our favorites. Bring your friends, no worries I already deny knowing you. Kidding of course. Which dink did you order from Defender? Using the same motor? Are you going to donate the smallest dinghy in the world?!
 
Russ Calasant said:
Thanks Rod. I am glad you guys liked Block, it's one of our favorites. Bring your friends, no worries I already deny knowing you. Kidding of course. Which dink did you order from Defender? Using the same motor? Are you going to donate the smallest dinghy in the world?!
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The Zodiac Zoom 260S
http://www.zodiacmarineusa.com/zodiac-tenders/zodiac-zoom/260-s

here is a pic of me in it:

zodiac_zoom_c.jpg
 
I am rafting up with Alex F this week end... He may younger than I, but he always has great words of wisdom, and a lot of common sense. So, initially, I plan on initially strapping the bikes to the bow, and strap the dinghy swim platform. When I see Alex, he may have some better ideas... I have in the past put a car bike rack on the swim platform for the bikes, but I don't think I will have the room for that. My ride is less than an hour, and it is in the bay, so I don't expect it to be too rough...
 
Irene has delayed any progress on the engine diagnosis. The marina used all last week prepping for the storm as an excuse and so far it's been cleanup so no news. I am getting anxious as time is ticking away.
On a good note, I had been having a voltage/charging issue and I called Pro Mariner to help troubleshoot. They seemed to conclude very quickly that it was the charger and I was not convinced but took their offer for a discounted replacement anyway. I swapped it yesterday and sure enough it solved the problem. All batteries are showing charging at 14 volts! (AGM charging profile). I have never seen anything above 12.8, what a difference! Should have swapped it a long time ago.
 
Okay, finally after an unbelievable altercation with my marina I moved it to a better facility and they got the head off on Friday. First I will summarize the altercation, I thought I had been pretty patient. I knew the storm timing and my engine failure were not good and acknowledged so. However I gave my marina a weeks notice and they scheduled me for Monday after my return. They didn't get to it so they stated Tuesday. Wednesday I heard nothing still so I asked and was told "busy for storm prep" okay so I wait. The storm came and went Sunday. By Wednesday I still have no word so I send an email asking for a date to expect service. In response I recieve a scathing email stating how appalled and outraged they are by my request. They go on to say how it's obvious I have no idea how to run a business, how insensitive I am for not considering all the people, thier families, businesses and agencies that have suffered due to the storm and how I should take my business, all of it including my slip elsewhere. It gets better. So I respond in kind explaining that it is I that it is appalled by thier response to my request and that I would be happy to bring my business elsewhere. I invited them to meet or a phone call to further discuss. You can imagine how angry I was/am but I am
not so foolish to put it in writing as they were. So I made other arrangements. Tuesday night I get an email from my marina stating they are now in work mode and no longer in storm mode and are ready to work on my boat- HA! The next morning I am departing to a better facility and the yard manager (the offensive email writers husband) comes running down the dock asking if I got his email. I asked if he had read his wife's response to my request, he responded yes and I responded - then you have your answer! And I left. Keep in mind there are two sister yards, they are run by a husband and wife management team and half a staff shared between the yards. Rumor has it the absentee owner is seeking bankruptcy protection. On to the next post.
 
Next,

The new facility is close by and has an excellent reputation from everyone I have talked to. As apposed to my marina where I cannot find a single person that has not had a bad experience. So they pulled the head on Friday afternoon, not good. I don't understand a lot about this but there is something about an exhaust valve failed. Debris from this failure went into the cylinder and there were some small pieces embedded on top of the piston. He told me they would work up some pricing and options for next course of action. This is the way I understand it and estimate costs at this time- Monday I should have better numbers. Option 1 - replace the motor, approx $12k. Option 2- pull the block replace the piston, head and reinstall, approx $7k? Option 3- they can smooth the top of the cylinder, replace head and reassemble, approx $4k. They estimated the cost of engine replacement, I estimated the other 2 options. The motors have 720 hours. The MC master mechanic testified that he has performed option 3 several times and has yet to see a failure. At this point I am leaning toward option 1 or 3. I like the new motor idea but I don't line that the other will still have 700 hours. Replacing both is out of the question financially, 1 is tough. If option 3 is a viable option and it puts the boat back into the same condition prior to failure then I like it. I just don't know.
 
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