Need some advise

[willy]

need some ideas from you guys before I head back down to my V.
Took my son down yesterday to install rod holders on boat, went well and we decided to go out and do a little fishing late in the day.
Motor is running like a champ, full rpm and speed but a noise is occurring at higher rpm that sounds like a metalic vibration, medium high pitch and would come in only under load when you were first accelarating then quiet down and sometimes disapear.
Stopped motor on the watetr and pulled the cover, sounded like something was loose like a ball bearing in a paint can mixer machine but could not see anything wrong or loose. No alarms, no overheating, oil in reservoir.
Ran boat for another two hours and ran beautiful but noise would appear at certain rpms and repeat the cycle. Lifted the lower unit out of the water all looked tight there with prop but the noise seemed higher like around the base of engine block area but could not pinpoint at all.
Back at the dock had engine running with cover off and revving up high but could not get it to do it, only way was at speed on the water.
At higher rpm at high rpm at dock sounds like a two stroke swiss watch.

Oh and its a 1992 150 yammie.
Any ideas of what to look for let me know please cause I am stumped and now a little worried.
Only thing done diffrent on engine was I used Pennzoils new two stroke oil in the tank when I filled it up last time, I was going to use the yammie lube but it looked like he had been running Penn in it as it was not blue like yammie but black.

[tsubaki]

Normally the cowl is the culprit in most of the noises.
Ain't but a couple of other things that wouldn't show up easily.
Check the starter bolts, air damper and carb bolts or nuts.
Also look toward the bottom of the motor around the powerhead and even with a magnet for the spots you can't see for a hidden dropped bolt or nut.

[willy]

Thanks Tsubaki, going to do just that, the noise sounds external to the engine but visual showing nothing yesterday???

[parishht]

May be a bearing going bad in your lower unit.

I remember on my older cars that when the water pumps went,
they would make a noise and nothing looked wrong on the outside.

[willy]

how would I check for that Parish? any idea?
It does sound higher but I know vibration can carry a lot

[C YENSEN]

sounds like the solution to the problem is hanging on the back of Lumber's boat not to far from you......i will even come up and help you "borrow" it:zip:

[parishht]

An engine stethescope could help you pinpoint the noise.
The other way is to tear down the unit and check each bearing.

But ifI understand your post,
the noise is only when in gear, under power with a load (pushing water).
That would indicate something in the drive.

[macojoe]

When I got my 94 150 Yamaha it had a noise like that and was junk right after?
But that said that motor had ben over heated before I got it and who knows how or for how long?

Good Luck

[C YENSEN]

I agree with Parrisht. take and old dow rod or piece of long skinny wood (broom handle) and hold it to your ear, and possible noise areas. should tell you where the noise is coming from.

[willy]

that sure would be tricky at 28-35 mph on the water cause it makes no noise at all sitting at the dock at full rpm
better get my life ins up to date, I can see it now, man dies on water with broom stick in his head!!

[THEFERMANATOR]

that sure would be tricky at 28-35 mph on the water cause it makes no noise at all sitting at the dock at full rpm
better get my life ins up to date, I can see it now, man dies on water with broom stick in his head!!

:you: That there is funny, broom stick in his head.


Have you tryed putting it on the trailer and loading the engine that way? That would allow you to load it while not moving to help narrow the noise down in a slightly safer manner. Maybe you can get us an audio clip of it? Check your lower unit oil for milk obviously, and maybe try another prop to see if it's a harmonic balance issue in the blades. I had a MERCURY prop once that made the noises you describe, noises went away when I got a MICHIGAN WHEEL back on it. You could also have a reed valve cracking since you say it only does it pulling a load.

Probably wouldn't hurt as well to get you a 10MM 1/4" drive swivel socket and ratchet set-up and go and tighten all of your pan mounting bolts. The YAMAHAS use bolts go in into the pan with large round washers on them and can make the exact noises you describe.

[tsubaki]

If we need to check stuff like that, we would have the boat tied to the dock and gradually increase throttle till hopefully the situation presents itself.

[eight]

Could be detonation. Try some high octane gas.

[randlemanboater]

My control cables sometimes vibrate in the splashwell at certain rpms and make a terrible noise.......try moving them when its making the noise.

[spareparts]

look under the flywheel for metal shavings, I've seen stator bolts back out and cause contact with teh flywheel. I freind of mine had a 130 Yamaha that knocked from the first time I met him, it kept on for about three years, He started runnign ringfree with his gas, after about two tank fulls, the kknock went away. I don't have a clue wat it could be, but its had three more seasons on it since

[willy]

all right here is the skinny so far, went down to the yard and started inspecting for obvious things, nada, then I realized something was not right and it hit me I was missing my little fin above the prop, it fell off apparently and when I checked the bolt rattles around loose inside. Ran down and picked up a new zinc and installed. Launched boat but noise is still there.
Had boat pulled and went thru every nut bolt on it and all looked tight and clean.
Had the engine cover off and I notice that the cowling has three heavy duty formed in stems that contact three corresponding metal tabs on the lower half. Two of the three have heavy rubber blocks on them, fit like a nipple over the tit.
One missing and not to be found, this would definetly make a vibration from the looks of it and would fit with it coming on under heavy vibration and acceleration and fading away once you level off.
It would also fit with the fact that at the dock me running the engine up high rpm and no noise, I had the cover laying in the cockpit!!
So going back down tommorow after a stop to a yammie shop for the rubber part, they were closed when I found it this afternoon.
Saying a little prayer this is it because there is no where else external to look and at a 120/hr I sure as heck cannot afford to have someone diagnose it.

[C YENSEN]

hope thats it. good luck brotha

[willy]

thanks Cy, got delayed family wise this morning going down later in day, if you guys got any other things that come to mind let me know

[willy]

Well boys the sea gods smiled. I went down today after picking up the grommet at the yammie dealer and installed it, launched her and the noise/vibration was still there.
So I took my time and kept listening for when it would come in and I noticed that when I induced it with throttle I could also stop it by putting pressure on the steering wheel.
Voila!! found the bolt on the steering arm had backed out enough to allow the arm and the steering rod to vibrate. Took out my trusty Leatherman and tightened her up and no more vibration. GONE like that.
Thank you Lord, celebrated by going fishing by myself on the V. She is sweet by the way runs like a champ. Or did I tell you guys that already.
Anyhow thanks all for the imput, except you MJ, you scared the bejeezus out of me.:beer:

[THEFERMANATOR]

I bet that bolt had a large flat washer on it too. I've heard that noise before from them large fender washers waffling around and vibrating.

[reelapeelin]

Willy...I junked my old Rude thinkin' internal problem...turned out to be loose magnets under flywheel (don't know if yer Yam is set up same way or not) look for the easy stuff first...




see...turned out the easy stuff, HUH???...