Motor mount bolts

[jzumi]

So, I just got the boat back from the shop. I went to change the crankcase oil and I noticed a very corroded lower motor mount bolt. The shop had to remove the power head to replace the bolts amd dampers. Almost $3K.

This is on a 2007 Yamaha F250. The motor mount bolts are hidden by the lower cowling which you remove to get to the oil drain plug. The mechanic says the bonding wire was corroded.

Question: How do you flush this area of the motor since it is under the lower cowling.

Next question: how do you check to make sure the bonding wire is properly hooked up since it is inside the damper housing that is under the lower cowling?

It would be really nice to make sure these new parts have a chance at a long and productive life!

Thanks,
John

 

[warthog5]

Ahhhhhh! I know the exact bolt your talking about behind that cover and below the drain plug.

I just did my 1st service on a 2011 F250 Yamaha. [Never messed with one before]

147hrs on the motor....Yes it was rusty and flaking also.


I can tell you this....The more I'm around these Yamaha's........The More I Love my Suzuki's.

Much easier to service and don't have a weird size oil filter.

 

[Miss Virgie II]

The guy I had bought my boat from had drilled an approximately 1" hole on each side of the upper portion of the plastic cowling. These holes are used to spray fresh water into in order to rinse those bolts (which I religiously do after every trip). The holes are capped with a thin, solid rubber grommet. I have had my boat for 4 years, and leave her in the water. At the end of every season, (or more if I pull the boat out for any reason) I remove the cowlings to check the bolts (and to change the oil) and I can say that there has been a very little surface rust on the bolts, but I just wire brush it off and they are good as new. I also forgot to mention that I pack that area around the bolts with grease. Hope this helps....

 

[jzumi]

Wow, this sounds like a very poor design.

I am kinda okay with drilling flush holes in the cowling. Although I'm pretty sure that would not flush the bonding wire and the places it attaches to since all that is under the damper housing.

Perhaps I will give the bolt head and washer a coating of Corrosion X every time I change the oil and flush with fresh water through the custom flush holes.

Wait! Do you think CorrosionX is okay for the rubber damper?? Would marine grease or some other substance be safer?

 

[Miss Virgie II]

I don't know about the corrosion X. I just use the marine grease.....


Also, my bonding wires have zero corrosion, so my system must be working. Give it a try and monitor the results. It has to be better than doing nothing....