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Author Topic:   Too Quiet Four Stroke
elaelap posted 03-04-2003 01:42 PM ET (US)   Profile for elaelap   Send Email to elaelap  
I'm in the process of breaking in my new Yamaha 50 hp four stroke on my 16/17...and loving every minute of it. Just talked with the dealer about a prop switch (he's moving me down from a 15 to a 14 pitch, since I'm only getting 5300 rpm at WOT), and during our discussion he told me the following cautionary tale, which he swears is true:

One of his customers arrived at the Bodega Bay boat ramp with a very full bladder, hurriedly trailered his boat (a aluminum Klamath with the same motor I have on my Katama), and towed up to the restroom, where he sought blessed and immediate relief. Unfortunately, because the motor is so quiet at idle he neglected to turn it off before he put it on the trailer, and didn't notice it was still running until the overheat warning sounded. Result-- fried housing and impeller, with some serious problems trying to claim repairs under warranty.

The story sounds too good to be you folks think it's a Yamaha P.R. man's fantasy? The motor IS amazingly idle and trolling speed I literally can't hear it running over the sound of the sea.

Anyway, for those who care, I'm very pleased with my new motor so far...up on plane within 2-3 seconds, 32 mph GPS/WOT, good gas mileage, and oh so silent running, all with a five-year warranty.


Dick posted 03-04-2003 02:07 PM ET (US)     Profile for Dick  Send Email to Dick     

I am running the Merc 50 4 stroke on my Montauk (Yamaha powerhead). I dropped to a 13 pitch and top out at 33 mph at 5800.


elaelap posted 03-04-2003 02:07 PM ET (US)     Profile for elaelap  Send Email to elaelap     

Thanks to all of you on this site for your generous help teaching this old sailor a little bit about motors, props, etc. I didn't know WOT from waterbottle (or, as I whined in an earlier post, pitch from petunias) when I joined this forum four months ago. Special personal thanks to BigShot, who took the time to email me several times with valuable advice re these matters.

Finally, thanks jimh...what can I say. My boat's just about ready for the season, emerging like a butterfly (no...I better say "moth"...she's only a beautiful butterfly in my biased eyes) from her cocoon of harsh use, and this forum, and your firm, wise leadership of it, has made the past four months a wonderful experience.
Please forgive this sentimental post, all you tough must be Spring, and salmon season is only five weeks away!


elaelap posted 03-04-2003 02:25 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Thanks for that, Dick. I just talked with the wrench at the boatshop, and he will be putting on a 13 rather than the 14 pitch tomorrow, which I'll test immediately. Glad you're up and around, old bud...and this is another example of what I was lamely trying to express above.


captbone posted 03-04-2003 02:37 PM ET (US)     Profile for captbone  Send Email to captbone     
Any motor running out of the water even at idle is still going to be pretty loud. It is possible but then again so is having a deaf man doing the same thing with twin 225 mercs. Sounds like a fish tale.
lhg posted 03-04-2003 02:51 PM ET (US)     Profile for lhg    
My sympathies to you for having bought an engine from a Dealer who SWEARS a Yamaha 50 4-stroke makes NO EXHAUST SOUND when running on flushing earmuffs. I'd watch this guy, since he can't be too bright either.
elaelap posted 03-04-2003 02:52 PM ET (US)     Profile for elaelap  Send Email to elaelap     
captbone: You're probably right. I don't know how loud the thing is out of water, because Yamaha has built in this nifty hose hook-up which allows you to rinse the cooling system with fresh water without using "earmuffs" and without turning on the motor. On the other hand, I could see a guy hopping in his truck, with the boat still in the water, and driving off --perhaps with the windows rolled up--and with his attention focused on his nether regions and his bursting bladder fail to notice the sound of his motor 25 feet in back of him, at least until he got out of his truck again. But it sure smells like fish to me, also.


russellbailey posted 03-04-2003 02:52 PM ET (US)     Profile for russellbailey  Send Email to russellbailey     
I have a hard time believing he didn't hear it running at all. But they are pretty quiet. Following is a true, low intelligence story with yours truly as the guilty party.

This last summer we rented a 28' pontoon for a family gathering, that had a 75 or so Honda on it (I forget the exact size - maybe a 90 - but it was a Honda).

A thunderstorm blew up and I was in a hurry to get the anchor up and get going. I started the engine and put it in gear and nothing happened - holy cow, it is still tilted out of the water. It was out of sight at the back of the pontoon and between that and the more quiet motor, it was not as loud in the air as the 1987 70 Evinrude on our Striper when the 70 is in the water.

I did notice and shut it down in 3-5 seconds - it really startled me - I've been boating for 25+ years. I never would have done the same with our old motor - you'd notice it in a second.

I was honestly amazed at how quiet the motor was even tilted out of the water.

elaelap posted 03-04-2003 02:55 PM ET (US)     Profile for elaelap  Send Email to elaelap     
lhg: Nobody SWORE anything to me, nor did anyone talk about flushing earmuffs or anything else...please re-read this thread, and save your sympathies for those of us who can't fish for salmon for another five weeks, unlike you.


elaelap posted 03-04-2003 03:13 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Whoops, lhg, I did say the dealer "swears it is true..." Maybe I was just taking a bit of literary license there..."swear" to me is of special importance, since I'm (forgive me) a lawyer. But this gives me a chance to express my envy about you being able to take Coho way here in N. Calif.


dgp posted 03-04-2003 08:55 PM ET (US)     Profile for dgp  Send Email to dgp     
Tony, my Mercury 50hp four stroke is so much louder out of the water than in, it would be hard for me to not know it was still running when I pulled it out of the water. While this motor is quieter than a comparable 2 stoke at idle, there is no doubt when the engine's running at idle...and I'm half deaf from riding motorcycles and being around engines all my life.
Bigshot posted 03-05-2003 10:59 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
My 70 zuki is about the same out of the water as in, maybe a tad louder. I was shocked the first time I cranked it up on the muffs after installing it. I could see it happening but I doubt it would not have sounded the alarm before he parked the truck, etc.
Taylor posted 03-05-2003 04:36 PM ET (US)     Profile for Taylor  Send Email to Taylor     
While there are no flushing earmuffs involved in the story, I think lhg's point that when run on flushing earmuffs, the engine would make plenty of noise. Considering the story: the moment the exhaust outlets came out of the water, there would have been a racket. So the salesman's tale strikes me as far fetched.

Unless of course these Yamahas have a built in muffler.

elaelap posted 03-05-2003 07:57 PM ET (US)     Profile for elaelap  Send Email to elaelap     
Hey guys--

I didn't mean to start a controversy...just repeated a tale that I twice said was probably a public relations hook baited for new fish like me; only thing is, I already owned the motor, so why the BS, if that's what it was?

Anyway, took a day off and got out on the water...beautiful day off Bodega Head...Coasties said 5-7 ft swells with 2-3 ft wind waves on top, 10-15 mph northwesterlies; it was much nicer than that ...light breeze, crystal clear blue sky, long, lazy swells with almost no chop.
Only saw half a dozen other boats the whole 3 hours I was out of the harbor...lots of seals, cormorants, and other critters.

I've now got over 9 hours on my motor...not a complaint so far. Mileage is incredible, especially taking into account that this is break-in time, and I'm purposely running at different speeds rather than seeking optimal cruising speed/trim and then sticking to it for long periods of time. Plus, I'm encouraged by the manual and the dealership to go up to WOT every half hour or so, but not for more than 5 minutes (!!sure...five minutes of leaping off swells and giving me even more gray hair --a long thirty seconds every now and then was enough!!)...I'll rarely if ever have the motor wide open once I break it least not out of Bodega. I'm getting a comfortable -- for me -- 16+ mph/GPS at 35-3600 rpm.

Changed the prop from a 15 to a 13 pitch (thanks Dick!), aluminum, and got my WOT right where I want it...5800 and 5900 depending on the boat's trim and attitude toward the wind and waves. Top end dropped down a little, to 30 mph, even with 500 more rpm...I don't get it, but the dealership wrench said that's what to expect with my High Thrust motor. I don't really care about top end anyway...and the boat jumps up on plane almost instantly and stays on plane at 12-13 mph when I figure out the trim right...

Thanks again to all you nice and knowledgable folks...this has been a very exciting 4 months, and everything you guys said about the smirkless 16/17 is true...wonderfully forgiving sea boat but a tad hard on one's teeth and ass.


weekendwarrior posted 03-06-2003 09:20 AM ET (US)     Profile for weekendwarrior  Send Email to weekendwarrior     
I totally believe the fried water pump story, the same thing almost happened to me when I first got my Honda 4-stroke. My brother drove the boat on the trailer and he sat in the boat while I pulled it out. I parked to the side and he started handing me things over the front of the boat and then when we moved towards the back I heard a faint noise...put.put..put..put..put... I run back there and the $(*&! engine is running! It only ran for about 30 seconds at idle and we were spared any damage, but these little engines are extremely quiet at idle, even out of water, and at a noisy boat ramp it's easy to not hear it.

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