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  Topic Review (Newest First)
05-16-2014 12:21 PM
Re: Atomic 4 Shakes the Boat

05-15-2014 11:50 PM
Re: Atomic 4 Shakes the Boat

The A4 is probably the smoothest running marine engine I've encountered in more than 6 decades on the water. Glad you were able to solve the problem with low expense.

05-15-2014 08:29 PM
Re: Atomic 4 Shakes the Boat

I thought i had given you all an update last year, but it appears i did not. The issue indeed was the prop, it threw a blade which, lucky for me, didn't harm the boat. But.. 4 weeks after replacing my prop the motor ate itself. I've converted her into an outboard and i love the extra space where the engine once was. Thank you all for the great tips!
08-27-2012 11:38 PM
Re: Atomic 4 Shakes the Boat

Originally Posted by Ringoparr View Post
UPDATE: It turns out that one of the 2 blades had fallen off of the prop!
That'll certainly do it.
08-27-2012 11:37 PM
Re: Atomic 4 Shakes the Boat

If you have one available, a drywall saw will generally make quick work of whatever has fouled your prop.
08-27-2012 05:41 PM
Re: Atomic 4 Shakes the Boat


I hired a scuba diver to scrub the bottom of the boat and take a peek at the prop. It turns out that one of the 2 blades had fallen off of the prop. The previous owner had claimed to have installed zincs but there was nothing! Luckily the shaft was fine and the missing blade didn't touch the boat as it exited. The scuba guy was great, best $45 i've ever spent.

I've since found a new prop and am having the same scuba guy install it, and a zinc, before the weekend.

If anyone in Everett needs a scuba guy, let me know and i'll share his contact info.

Thanks everyone for their tips and info!
08-18-2012 06:53 PM
Re: Atomic 4 Shakes the Boat

Would bet you a beer that your prop has a lot of growth on it. When it starts cavitating, you are effectively losing your 'bite' on the water and spinning the prop in air bubbles as a result of the growth, which is why the engine is accelerating but your speed isn't. The cavitation is also the source of the vibration you're reporting. Usually, reducing throttle speed will help, but you really just need to clean your prop and she'll be good as new. Ignore it and you'll soon feel as though your prop is missing. This time of year, growth is quick to accumulate. Do it yourself or hire a diver -- git 'er done and get back out sailing.
08-18-2012 07:00 AM
Re: Atomic 4 Shakes the Boat

Does it shake when you Rev it in neutral?


Supernatural Season 7 DVD
One Tree Hill Season 9 DVD
08-18-2012 03:22 AM
Re: Atomic 4 Shakes the Boat

When you say that the motor got loud, did it sound like the exhaust got louder or was it more of a thumping/vibration? If it's the former then there may well be something wrong with the engine itself. If the latter, like others have said, it's probably a fouled prop, bad motor mount, bad cutlass bearing, or some combination of those.

BTW, I would look for a new mechanic if I were you.
08-17-2012 11:23 PM
Re: Atomic 4 Shakes the Boat

Bread knife works best IMHO.
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