My Winter Maintenance project

colhel

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Now I've had a bit of practice posting pics, I thought I'd contribute a new thread which may help waste 5 minutes of your time.
We bought our boat, a Nimbus 3003 in August of 2018 having initially rejected her on the Sea Trial (I might do a separate thread on this to waste more time)
When the boat was launched I was informed that no anode was required on the sterngear, even though I was prepared to purchase one prior to the launch for the Sea Trial...
Anyhow, fast forward to April 2019 I had the boat lifted for a bum clean and fit a rope cutter arbour in preparation for a cross channel trip over the Easter break and it was quite obvious to me that the advice (however well meaning) was wrong and that I had to remedy it fairly quickly while the boat was held in slings, fortunately the boatyard gang were having lunch. I ran up to the Chandlers in Portland Marina, found a 40mm shaft anode, rushed back to fit it, only to find it was too long to fit between the shaft and rope cutter, there wasn't a tapped hole in the end of the shaft so no other alternative but a shaft anode. I then ran (I'm out of breath by now) round to Mechanical Services in Portland, a company with a well deserved reputation for service, to see if they had anything that would fit. They didn't but offered to machine the face of the anode to fit, I ran back to take measurements, boatyard gang finishing lunch, back to Mechanical Services (that company with the deserved reputation for good service) Had it machined to size for a tenner, they were happy with a coffee contribution, ran back and fitted it.
Here's a pic....hopefully1.jpg

Some may remember this picture and the concern it created amongst some members here. Basically, this being my first motorboat, I didn't equate the effect of having so much unsupported shaft protruding from the stuffing box.
Fast forward to the Summer and we're back on our home berth at East Cowes and I showed the picture to our new neighbour who took the time to explain what the issue was, which was, the amount protruding should be no more than 1.5x the diameter, in this case 60mm, which clearly this was nearly twice that and I should take steps to resolve it at the next opportunity.
I'll post this thread now but carry on as a reply in a minute.
 

colhel

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October 2019 and I'm ashore at Deacons, my neighbour is now a friend and is offering his services to help.
Initially it was hoped we could either have enough room to drop the rudder and pull the shaft through allowing me to either cut it short or make a new one. This wasn't possible unfortunately due to the ground clearance, another idea was to slide the shaft out of the clamp and cut it with a cutting disc but being a single engine boat the shaft was inside the profile of the keel and impossible to get at with our basic cutting equipment.
Now me being rather new to motorboating and their sterngear arrangements, didn't notice a previous owner had fitted an R&D coupling, but as soon as my mate managed to join me on board and saw it he realised the answer was to remove it and this would allow the shaft to be pulled back inside and bringing the overhang outside back to the required 60mm, the R&D coupling being of course 60 mm in length.
Then more cans of worms emerged.
After removing the R&D coupling we (he) was alarmed at how much the engine was mis-aligned, so much so that shaft had dropped well below the centre line of the stuffing box and before any fine alignment could be carried out the whole engine needed raising to bring the shaft back into centre.
To help us I came up with the idea of making a spacer to fit between the shaft and stuffing box to hold the shaft in position while we adjusted the engine mounts. The shaft diameter was easy to measure but the inside diameter was less so as trying to get the verniers in such a position to accurately measure it with the shaft in the way was impossible, so I resolved to making a best guess and making a few spacers up which I turned on a lathe and then cut in half and by fitting one below and and one above the shaft and checking for play I would know the outside diameter would be correct.
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colhel

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So next job was to adjust the engine mounts which again incurred more challenges.
The first picture I took the previous Winter when I serviced the heat exchanger. Three of the mounts are relatively easy to get at, once you've got a disc cutter to your spanners anyway, but there's a mount below the intercooler which we found impossible to reach. the second picture is looking up at the gearbox and the engine mount isn't even visible
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The only way I could think of accessing it was to cut a hole through from the side cabin. Once this was done the alignment could be completed.
 

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longjohnsilver

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Is it the original engine ?
If one engine mount couldn’t be accessed without cutting the hole in the side cabin, I’d guess it must be the original engine.

Maybe the mounts have corroded over time, runners perished, or the hull has sagged slightly, any number of reasons for the alignment to be out.

Anyway, thanks Col for an interesting thread. Out of interest, we’re you suffering any undue vibration with the extra length of unsupported shaft?
 

colhel

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The boat is a 1989 vintage with a Tamd41a so a very good chance the engine is original and I suspect the R&D coupling was fitted as a shortcut due to the inaccessiblility of that mount. I will need new mounts fairly soon as they're almost at the top of their limit.
As last year was my first season with the boat it was hard to tell if the noise and vibration was excessive and where the cause was. This year she has a brand new prop, a shorter shaft and a re-aligned tightened engine, and the difference is huge! I suspect it's a culmination of all the work, but as the cutlass bearing seems in good condition still the extra shaft probably was only a small part of the problem.
Thanks for the interest and response, you've given me the impetus to carry on this thread ?
 

Bouba

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If one engine mount couldn’t be accessed without cutting the hole in the side cabin, I’d guess it must be the original engine.
That’s what I thought at first, but looking at the photo it appears that the engine mounts are connected to the engine by removable brackets. Which might be accessible to remove the engine. I don’t know but good thread
 

burgundyben

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Interesting thread.

I have previously been told that 2 * diameter is ok.

BTW - those collars to hold the shaft central in the log - nice, I have a pair for my boat, I have found that in practice you only need one in the bottom. Don't leave one in and reassemble the gland..... I did, thankfully, while wondering where I had lost one I realised before launching or running. Its a design fault with mine, they could be made with a wider brim on the hat, that would stop the gland being assembled.
 

burgundyben

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The boat is a 1989 vintage with a Tamd41a so a very good chance the engine is original and I suspect the R&D coupling was fitted as a shortcut due to the inaccessiblility of that mount. I will need new mounts fairly soon as they're almost at the top of their limit.
As last year was my first season with the boat it was hard to tell if the noise and vibration was excessive and where the cause was. This year she has a brand new prop, a shorter shaft and a re-aligned tightened engine, and the difference is huge! I suspect it's a culmination of all the work, but as the cutlass bearing seems in good condition still the extra shaft probably was only a small part of the problem.
Thanks for the interest and response, you've given me the impetus to carry on this thread ?

Seems likely, the AVM's have settled, they couldn't get alignment right cos of the access issue, so they fitted the R&D coupling.

I think I saw some AVM engine mounts that you can adjust up and down from above, like a hex key or something that slots in the top and you wind either way. Maybe I'll google that later as I'll need a set of AVM's soon enough.
 

colhel

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I was wondering what AVM stood for aswell :)
Regarding the collars to hold the shaft central, the reason for placing one top and bottom was to check I made them the right size as when I measured up I couldn't get an accurate measurement of the stuffing box while the shaft was in place. When we actually did the work we only needed the bottom one in place, as you say.
One of the other concerns was if we couldn't adjust the mounts due space limitations so I made up some shims of various thicknesses that could be slid into place. They're for M16 mounts and are surplass to requirements if anyone wants them. But I think they might be on board...10.jpg
 

colhel

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When we removed the rope cutter to allow us to push the shaft up we discovered quite a bit of pitting due to corrosion where the rope cutter had been seated on the shaft, ideally I need a new shaft but time ashore, extra lifts and manufacture would be stretching the family budget somewhat so I decided to fill in pits with a two pack epoxy and fair in with a sander and by hand. This section of shaft is now inside the cutlass bearing and I'll machine a new shaft from duplex this year and hopefully be able to schedule it for fitting next Winter.
The next issue was fit an anode, but without a tapped hole in the end of the shaft and no real way of drilling and tapping it with the rudder in the way, I decided to make my prop nut that I could fit an anode too. I since found out these can be purchased so my idea wasn't unique :)
Below are pics of my nice shiny new prop, the nut I made at work on their Colchester and Bridgeport and the whole assembly ready for launch.
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vas

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good, I was gonna say that the prop in post #1 didn't look that good to me :D

I guess all the alignment was done in the water right? If not, shouldn't it be rechecked/done when floating?

cheers

V.
 

vas

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The alignment was done ashore but the plan has been to re-check and adjust if necessary after a couple of run outs.
do you really need any runs out if you've not changed mounts or something?
I mean mine is more than a few mill off when on the hard (doesn't help that it's timber and ground is not at all flat and supports are all over the place), just saying!
It's fine when afloat though.

V.
 

colhel

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do you really need any runs out if you've not changed mounts or something?
I mean mine is more than a few mill off when on the hard (doesn't help that it's timber and ground is not at all flat and supports are all over the place), just saying!
It's fine when afloat though.

V.
The mounts are now near the top of their limit, it was more about checking incase the engine were to settle down onto the mounts. I didn't think about there the alignment changing once in the water, I can see your point now though
 

Kawasaki

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I did a similar job on my Nimbus
New stern tube,shaft,prop, stuffing box etc
Managed to get at the engine mounts and remove the Lump and fit new mounts
All measured and lined up ashore
Re measured twice later afloat
Very minimal movement after a 10 hour and 20 hour check
 

colhel

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Now all the work had been completed I guess this thread would benefit by me sharing the results.
I didn't take any pictures of "Infinity" with her fresh antifoul but here she is just after she was lifted ashore
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The boat was launched by the guys at Deacons in my absence, which wasn't how I'd normally do things but as we finished on the Sunday, I called them the next day to be told they had a slot to launch the same day. My biggest concern was that because we removed the shaft seal and prior to that the shaft had been running off centre it could have caused wear and thus a leak. The guys were extremely helpful and understood my concerns and assured me someone would be on board to keep an eye on things and generally watch over her once she was afloat. I'm pleased to say all was fine.
The following weekend Helen and I drove down with the plan to start the much needed cleaning and of course a run out along Southampton Water.
As soon as the engine started it was immediately obvious she was running a lot smoother than the previous year, bearing in mind as yet I've done nothing on the mechanicals just the mounts, the difference was astonishing! Very pleased so far, but really the proof of the pudding would if there was any noticeable difference in performance.
The old prop as can be seen in the first picture of this thread was in a pretty poor state, also the anode can't have helped, but aswell when I approached a prop supplier recommended to me he advised me fit an 18"x17.5, looking at the previous invoices and researching the Nimbus recommend an 18x18.
Last season it was obvious we were down considerably on performance due to reasons listed but of course fouling too. So last year by the end of the season I was struggling to achieve 12 knots, where as when we first purchased the previous year about 22 knots was achievable at WOT.
Off we pot down the Hamble still reveling in the new found smoothness and quietness , out into Southampton Water, opened her, bow lifted a little, and the boof! we lost all drive the engine just revved in forward and reverse, no prop wash, nothing, zilch. Okay big problem, we're drifting outside the Hamble and approaching the shoreline off Warsash. At first I thought gearbox, but then my attention turned to shaft clamp which of course we'd loosened, luckily all my tools were still close to hand, and indeed it was loose. I think it was a case of me thinking My mate had tightened it, and him thinking I'd done it. A very embarrassing error! Anyway clamp tightened and we were on our way again. Phew!!
So after that drama we once again cleared the approach channel and opened her up again. Unfortunately the log had stopped working since the re-launch so I can't accurately compare top speed to last year, but but running up and down Southampton Water gave an average of about 23 knots and max RPM on the dial of 3850rpm so a little high but I'm not concerned as the bottom was spotless, the tanks weren't full and the boat had largely been emptied for the Winter, and there was only 2 of us onboard. Our normal boat usage in the season is largely to use the boat as a sort of apartment with occasional runs out with friends to somewhere local to East Cowes, hence normally fairly heavily loaded, so until those days are back it's again quite difficult to make comparisons but I'm hoping the finer pitch will pay off, but if not I've always got the option of a re-pitch.
We had another run out on New Years Day we my Brother and his family and met some friends in Anchor In Cowes for lunch and as we left one of them captured us on camera on our way back.

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The next trip out was to move to our Winter berth in Weymouth on the 5th January.
This was pretty uneventful thankfully, and with the log book on board I can't share many statistics but looking at the track on Navionics, from Lymington to Weymouth 2h 56m. We actually started the trip from East Cowes,called into Yarmouth and then Lymington and we used 92 litres of fuel. ( I filled up in Cowes and refilled from Andy's bowser on our arrival in Weymouth). You may note due to the priority given to the mechanical work, cleaning and cloth peg removal was on the back burner.

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The only other job I've managed to get nearly finished is to renew the decking on the small swimplatform.
I made this from sapele which I bought from our local builders merchant, I didn't want to use teak as I haven't a great deal of confidence in my woodworking capabilities and i managed to get this lot for a tenner. I've yet to fit it properly, the picture just shows it laid in place,

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So that's it really, for now,
Cheers All
 

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