Squeal on yanmar 315 2003 engine on test ride what is it?

[slimjim]

Last week I took a ride on a Albin 28TE with a yanmar 315 engine (box model) all went well and I was very impressed with the ride. We were out for about an hour or so, when we came back in before we docked the boat we put the boat out of gear and the engine started to make a Squeal sound, I thought it was coming from the prop/shaft at first, but then as we put the boat in gear it got worse as we moved into the harbor,

I opened up the engine box and then noticed the noise was coming from the back of the engine I think the belts with the pully or belts making the Squeal?? It went away when we were pulling into the slip.

Went down to the boat the next day and zero/no Squeal? The boat has not been used much over the last year, and it only did this after an hour or so of test riding and only at low speed out of gear and then in gear at low idel??

What could this be? Has anyone had this problem before and if so how much does it cost to fix? Also should I walk away from this boat and move on? Thanks for any replys. Slim

[joe.baar]

This sort of reminds me of slightly loose alternator belts. Readily fixed and not life-threatening. See the Yanmar manual.

[denchen]

Might be something simple like a v belt driving the alternator, could be loose or worn. The alternator puts a good load on the belt if the battery is low, 750 watt (60ish amp at 12v) is about one horse power and a slack cold belt will slip more than a warm one. A quick check to see if the belt is really loose will show if this is the trouble, other wise I would proceed with a lot caution

[slimjim]

Might be something simple like a v belt driving the alternator, could be loose or worn. The alternator puts a good load on the belt if the battery is low, 750 watt (60ish amp at 12v) is about one horse power and a slack cold belt will slip more than a warm one. A quick check to see if the belt is really loose will show if this is the trouble, other wise I would proceed with a lot caution

what if its not the Belt? Boat was getting 13.8v reading, the squeal started an hour after we ran the boat and when we were docking the boat and pulled it out of gear then when on when we were trolling slow and got worse, then stopped at higher RPM. no Squeal the next day but we did not run the boat only had idel at the dock.

[jleonard]

Might be something simple like a v belt driving the alternator, could be loose or worn. The alternator puts a good load on the belt if the battery is low, 750 watt (60ish amp at 12v) is about one horse power and a slack cold belt will slip more than a warm one. A quick check to see if the belt is really loose will show if this is the trouble, other wise I would proceed with a lot caution

what if its not the Belt? Boat was getting 13.8v reading, the squeal started an hour after we ran the boat and when we were docking the boat and pulled it out of gear then when on when we were trolling slow and got worse, then stopped at higher RPM. no Squeal the next day but we did not run the boat only had idel at the dock.

Probably uses more than one HP, might be closer to 3 or 4. Belts gets hot, stretches a bit plus rubber gets soft, now the belt is lower in the pulley where it doesn't grab as good gets residue on the pulley and now it squeals. Slow down the belt cools and then stops squealing.
Check belt for wear. Check pulley for rust and belt resdue and make sure it runs true.
If not the belt it could be an idler pulley (if there is one in the system), water pump or alternator depending on the sound of the squeal. Bearings make different noises than a loose belt.

[RobS]

usually the 6LP/315 squeals on initial startup up and on initial throttle up due to the voltage draw on the alt from the air heaters. look around the alternator area for rubber dust. when it squeals hit the belts with a short burst of belt dressing (or anything really) and see if effects the noise.

[slimjim]

thanks for all the great info and feedback, I will check it out this week, I am still looking at a few Albins. This site is awesome and I want to thank all the posters who are a great help to all and to me who is a newbie here at AOG. I really do love the Albins.

[jms02050]

I had the exact same symptoms with my 6LP - my issue was due to loose/worn belts. Easy to tighten and the squeal was gone. As Rob suggested, look for rubber dust around the engine where the belts are located.

[slimjim]

I had the exact same symptoms with my 6LP - my issue was due to loose/worn belts. Easy to tighten and the squeal was gone. As Rob suggested, look for rubber dust around the engine where the belts are located.

Thanks Guys, Thats what it was loose belts that are a little worn, we tighten them up and no more squeal. Again, thats for everyones help.

[slimjim]

usually the 6LP/315 squeals on initial startup up and on initial throttle up due to the voltage draw on the alt from the air heaters. look around the alternator area for rubber dust. when it squeals hit the belts with a short burst of belt dressing (or anything really) and see if effects the noise.

Rob or anyone, do you have the belt part numbers for the Yanmar 315 alternator? Mine has two small belts, I cannot read the part numbers. Doe anyone have them?

[RobS]

Yanmar 119775-77260

or

Toyota 90916-02452

Yanmar numbers changed over time:
119773-77250 to
119773-77251 to
119775-77260

[slimjim]

Thanks for the fast reply Rob. I will buy 2 extras tomorrow. I went to the boat today and found a lot of Belt Dust and one of the belts the 1st belt farthest from the engine was loose, the one close to the engine seemed just right, I started the engine and when I rev the engine a squeal was there.

Shut down engine and pulled the belts. then looked and felt new, and had a mitsubshi part number of MP-MF-1395 on both of the belts. Put the belts back on and tightened up the belts and took the boat out for a two hour cruise and all was good.

I will use these part numbers tomorrow and try to get the right extra belts for the boat. Thanks again for your help.

[RobS]

...and had a mitsubshi part number of MP-MF-1395 on both of the belts...

mitsuboshi part number.JPG

That is Mitsuboshi, a belt manufacturer. I believe that is the belt that comes in the Yanmar packaging so I think you have the right belt but they just don't hold up for long, especially if your engine is equipped with the air heaters.

[N4QC]

Good picture! When you change out the belts I would recommend that the rust issue on the pulley edges be addressed along with the smoothness of the edges...

Have fun,

[RobS]

Its since been pulled, rebuilt at an auto electric shop, cleaned, painted and reinstalled