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It’s a matter of some pride for me to keep our engines and engine lockers looking clean. While our 54HP Yanmars don’t look perfectly new, they do look pretty good IMO, and I try to take good care of them.

One thing I noticed when I had the opportunity to look at a friend’s 4600’s Yanmars was that each engine had the cover for the V-belt missing. I immediately thought of that as a negative, and even remember commenting to that effect. When the subject of those covers came up with a different friend though, he confessed that he had made it his mission to remove them from every boat that he ran. When I inquired why, he explained that having them gone made it infinitely easier to inspect the belt for both tension and wear, something that he liked to do as part of his pre-start-up engine checks. That made sense. We don’t want that belt to break when underway!

Subsequent to that conversation, I brought up the subject to another experienced friend of mine to ask him his opinion. He shared that if it was his own boat (not a charter bareboat), and he knew that nothing was going to accidentally fall into that area, he would remove them too. Interesting.

What say you?

26 Comments

  1. I removed mine on my 54hp Yanmars. Again easier to check belts. Had a cover on incorrectly once. Wore on the belt that returned the favor and chewed up the cover. As long as no one else is going into the compartments

  2. Alarmists worry about the worst situation.

    When did you last hear of a belt breaking?

    50 years ago when pulleys were a different shape, so were the belts, alignment was not always good and the quality of the belts was nothing like today’s ones. Then belt failure was indeed common, but it still took several months of continuous use.

    Nowadays, I would expect belts to last several years without problems unless there is something else that is drastically wrong.

    Insurance salesmen and engine repairers thrive on these sorts of anxieties. So check your set-up and form your own clear-headed view of the need for continual checks. Then put the cover on and keep the area clean.

    Mike

  3. Our volvo’s don’t have them. Only times I would like them is when I am working on the engine while its running and I am wearing a tie. Don’t want my tie sucked into the fan belt.
    j

  4. I have the same 54 hp Yanmar and chose to leave the cover on. The perticular v belts Yanmar uses creates a lot of dust and I think the cover helps contain it somewhat better than if it was removed. Personally, I take a few extra minutes looking around the engine room For anything else as I take the cover off to clean and inspect. That’s just me.

  5. Okay…I used John’s website (on the form) since I don’t maintain one any longer 😉

    My suggestion comes with some knowledge of automotive engines and little of marine engines…now all disclosures are made.

    Uncover the belt. While Mike is correct; they do last longer but that creates another issue…we forget about what we don’t see.

    Uncover the belt and cover the engine – there – I said it. They (engines) are necessary evils at best and I won’t go into the worst 😉

  6. “When did you last hear of a belt breaking?”

    On my last delivery, that’s when. The good news was that the belt broke when I pulled on it as part of my usual pre-departure checks and before I motored out of a narrow cut in the Bahamas, into a 5ft swell.

    The belt is a “consumable” anything that can be consumed has to be easily accessible in order to be checked and replaced. That failure will inevitably happen at the worst time (e.g. motoring out of a narrow cut…etc.). Anything that gets in the way of such checks and replacement has to be modified and/or removed. Even if the belt lasts several years how do you know when its going to break unless you inspect it as part of your pre engine start check EVERY TIME you run the engine.

    Gerry

  7. Wearing a tie while working on an engine??

  8. Its a safety feature and I prefer not to override safety features. Maybe be I am a little too conservative but I just imagine that one lapse in concentration while moving around the running engine and the tips of my fingers being thrown into the bilge, or worse. I would cut slots in that cover so I could see the belt bounce or dusting that may occur.

  9. The cover’s primary purpose is safety, keeping fingers and other things away from the belts while the engine is running. This can be a very real hazard in a walk-in engine room or in many industrial applications.

    I consider it acceptable to leave them off, IF there is no significant chance of a person being near the engine except to work on it, AND IF there is no loose equipment in the engine bay that could get thrown into the belts when the boat moves. But there aren’t very many applications where both of those conditions are true.

  10. Oddly enough, I had a alternator belt that was just about shredder a few months back. Half the inner V was missing. Gee it only had 500 hours on it ;-). Not having a cover made that easy to spot. Yes I always have spare belts(s) too.

  11. We have a walk-in engine room, and I can’t imagine wanting to be in there under way (which we do about once an hour in daylight and once per watch change overnight) with no belt covers. A recipe for losing a finger, or worse, if a wave hits at the wrong moment.

    That said, our belt guard also has a hole in it, I’d say about 3/4″ diameter, strategically placed so that a practiced finger can check belt tension on the twin V-belts before getting under way. In our case, the hole is OEM (Lugger), but I see no reason why you could not add such a hole in your Yanmar setup.

    With some experience I also know now exactly where to look for belt dust, a tell-tale sign of excessive wear. I suspect the Yanmars have a particular spot or two where it accumulates.

    Personally, I would not remove the guards. Some day, you may be forced to cram yourself into that engine compartment with it still running, and you’ll be glad to have a proper guard in place. Just my $0.02.

    -Sean

  12. Ours is off. Don’t know why but I suspect engineers that have worked on it prefer it that way.

  13. Our 4Jh3E’s didn’t come with a cover, but if they did I would pull them. Why hide something that should be inspected?

    Eric

  14. I worked with a man that lost a finger to a belt; someone started the machine while he was working on it. Also consider that belts often do collateral damage when they break. On the other hand, open belts run cooler and last longer, though the dust issue is real.

    The most common cause of breakage in this age is seized equipment (alternator bearings?); presumably you would hear it, but perhaps not if well insulated and both engines running.

    I would lean towards no cover. But keep the keys in your pocket and secure the engine cover (charter boat).

  15. I subscribe to the same school as the second friend: don’t hide things from yourself.

    And BTW, if the belt is generating a lot of dust, that dust is powdered rubber, meaning that the belt is wearing. It is either way too tight (wearing as it wedges into the v-groove on the pulleys), or the pulleys are misaligned.

    bob
    s/v Eolian
    Anacortes

  16. (or way too loose!) Either way, hiding the problem is not a good thing.

    bob

  17. Richard Pendergast (Hello Texas)

    The only belt break that I’ve ever experienced was during a bumpy late night offshore motorsail in one of the heavily transited Gulf of Mexico safety fairways. It took two seconds to discover why the engine was getting hot. It took less than 10 minutes to change the belt. As this was the 1st leg of our winter cruise, the belt had been inspected just days before and it looked good. I vote for no covers.

    I believe in the principle that any maintenance procedure that is difficult to perform, is done less frequently.

  18. For the record, I removed them.

  19. The best of both worlds would be to drill an inspection hole large enough to observe the condition of the belt and then reinstall the covers. You might even find a correct rubber plug for your inspection port.

  20. On my Chriscraft, I added a few small rare earth magnets to the tops of shorter bolts with epoxy, screwed them in, and then “snap” on the belt cover when needed. Makes taking it off real easy when checking the belt and gives me piece of mind when covered.

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