Stella Blue is fitted with the 8 Kw Kohler genset. This unit has been a reliable performer, with no issues as of the date of this update (12th season).
Mainship has been much maligned by some owners for the difficulty in performing service to the unit because of the installation of the sound shield which results in difficult access to some important service points. The genset sound shield is a wonderful improvement over previous installations without it, in terms of lower noise levels. The problem is, it makes changing upper hoses, valve adjustments, tensioning the alternator belt, and a host of other maintenance items very difficult.
In recent conversation with Mainship's General Manager Jim Krueger, he explained the sound shield was developed in response to suggestions from 390 owners, during the design phases of the 400. A soft shield had been fitted on some of the later 390's, but some improvement was in order. Mainship worked with Kohler to develop a system that would dramatically reduce sound levels while keeping the unit "user friendly" in terms of periodic maintenance. The rigid sound shield does just that.
Four hatches with quick opening latches, one on each side, and a removable top section, allow great access to all sides of the unit. The problem comes when you put the whole system in, under the cockpit deck, and up against the aft bulkhead. The top cover no longer becomes removable due to the lack of overhead space to remove the screws.
During the commissioning process, to add coolant to the genset, my dealer removed the cover by pulling the genset from it's normal position under the deck, to the hatch opening. It was quite a chore, so they felt it best not to put the cover back on, so that same maintenance could be done in the future without pulling the genset. There is no room to slide the ridgid cover back into place, but there is enough room to slide a more flexible piece of foam insulation into place and use some stiff foam blocks to hold it in place rather that fight with the screws. In the picture above, you can see the foam cover and foam spacer block to hold it in position.
The other access problem is the side up against the aft bulkhead. It is nearly impossible for a normal sized person to crawl from the cockpit hatch area, around to the opposite side of the unit. Removing the battery and seawater stainer would help, but is a lot of extra work just to tighten an alternator belt for example.
Any repairs in those areas, like changing a starter, alternator, an upper coolant hose, or such, will likely demand that the unit be extracted from it's position. This is where the complaints come in. The installation does not permit easy extraction of the unit. The screws that hold the unit in place are inside the already cramped cabinet, making a bad situation worse or more difficult. This could have been better thought out by the designer.
There have been some suggestions to cut in hatches in the cockpit deck to gain better access, but this would be a great additional expense to the owners as well as a possible degrading of structural integrity of that deck. It is hoped that Mainship engineers will come up with a solution for us "400" owners.
In looking at the layout, a sliding rack could be fashioned to allow the unit to be slide aft to gain better access. This could be fashioned easily from angle stock. Hoses and power lines could be lengthened to provide a loop to allow for this motion. When the day comes, this may be the route we take with Stella Blue. The muffler could be moved aft to provide more room. for the "slide". The deck support tube would have to be removed during maintanence with this system but this would be a small price to pay. I know as I grow old with this boat, something will have to be done.
Anyway, on to other maintenance issues.
Below, just below the water pump and to the left of the hose to the heat exchanger, lies the bronze plug which holds the zinc. It's near impossible to change the zinc while the hose and clamps are in place.
There just isn't room enough to swing wrenches.
By removing the hose, you can greatly reduce the aggravation factor. You can now get to the zinc with a box wrench through the starboard hatch in the sound shield cabinet.
While we're looking at these pictures, What's wrong with the first picture? You have to hope you never need to adjust the belt much. If you move the pump through the range of adjustment, the bottom hose will not stretch long enough to fit. The adjustment should have been on the top end of the pump. Another frequent question is the changing of the waterpump impeller. The easiest way is to remove the bracket with the waterpump and change the impeller on the bench. Never try to remove the pully to try and remove the pump from the bracket. You are more likely to damage the shaft and/or bearings in that way.
If you use your genset, you will find much black rubber belt residue in the compartment. The belt needs constant retensioning, which is also just short of impossible with the sound shield in place. getting at the lower rear alternator bolt is a real chore. Best best is to remove the battery for elbow room and lay a big foam pad over the seawater strainer to protect your side. It's a real trick to find the right tool to wedge between the alternator and engine to hold tension while you retighten the bolts. I couldn't explain it even if I could remember.The tough part is getting to the back side of the adjustment clamping screw in the picture below.
I find that with generous padding over the water strainer, I can lay in there and get my arm up from underneathe the starboard side of the genset and use a shortie wrench to loosen and tighten the clamping screw.
Another trick is changing the engine coolant. The coolant fill is at the top of the unit and there is no room between it and the deck to pour coolant into the fill. The thing to do is use a funnel with a piece of hose to run into the fill. Keep a finger inside the fill to feel the coolant when it reaches the top. Of course you will need someone to help pour the coolant into the funnel.