View Full Version : Yamaha 350 Issues

Whiskey Bent
07-18-2010, 11:16 PM
Recently bought a used 2009 32 with twin Yama 350's.....

Got a complete service on both motors that included new plugs and all new filters including fuel filters also replaced both water pumps in the lower units.... The mechanic found the starboard lower unit full of water. From what they told me they are seeing this a lot on the 350's... They alleged there is a problem with the seals. they said they are constantly replacing the seals on the Jax Fire Dept motors...

So two days later we fished an SKA event and noticed that we lost a little speed... But on the way back on the first day of the tournament we noticed that the RPM on the starboard motor would fluctuate around 500 rpm.... but it seemed to correct itself. On the way out running around 90 miles south to Canaveral it started again but all in all the motors were running well....

Well next thing you know a loud knocking comes out of the starboard motor.... The lower unit is trashed.... We still fished and limped home 47 miles... When I took it to the same shop the pulled off the starboard lower unit and then found shavings on the plug of the port side. Now I am wondering how they didnt see any shavings on the starboard side when they serviced it.

Anyone else have any problems like this??? What frustrates me is that I just bought two new water pumps that cost a pretty penny plus the labor. I am getting the new lower units put on tomorrow... I am hoping to get credit for the two new water pumps and the labor...

I am also thinking of keeping a smaller prop on the boat to switch out in case I lose a motor. We were not able to get up on plane and could only go 10 mph.

09-08-2010, 03:42 PM
I know a few guys running F350's and have had water in the L/U. I have only had water in the L/U once and that was caused by a bad L/U screw. I replace the gaskets every time I change the L/U oil and the screw every couple of times. There will be shavings on the magnet every time you change the L/U oil.

The Filthy Animal
09-08-2010, 10:39 PM
I blew a port motor lower unit last week on my 32. 300 Vrod.... 490 hours, it happens. I can say, there has been no water in my lower units life to date. Funny you mention the RPM fluctuations.... I was having the same thing happen on that motor the day before it sheet the bed. What was actually happening was that that motor needed a little more throttle on and off to maintain the same RPM as the starboard motor. Next day, 13 for 17 butterfly jigging bluefins and on the ride home with 20nm left to go.... ZING! gonzo lower unit.