Yamaha Outboard Parts
Yamaha   Yamaha Outboard Parts
Yamaha Outboard Forum Yamaha Outboard Parts Discussion Forum Yamaha Outboard Parts Boat Parts Yamaha Outboard Forum Outboard Motor Parts Contact Us
Yamaha Parts

Go Back   Yamaha Outboard Parts Forum > General Discussion > Yamaha Outboard Forum

LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 03-29-2016
Junior Member
Join Date: Mar 2016
Posts: 2
Default Help with stopping corrosion in F150 thermostat housing

I have Yamaha F150 2005 engine's inside the thermostat housing there is some corrosion underneath where the thermostat sits

I am wanting to do some preventative work to stop it going through.
Has anybody tried painting with zinc primer epoxy two pack or galvanised paint to help the corrosion.

tried metal putty did not stick, glass fiber lasted 1 year.

I be grateful for anybody's feedback on what they have done to stop the corrosion.

The engines have had new anodes in each year and have been flushed out every time they have been used using the attached water connection and on muffs for short time as the engines over heat due to low water pressue in the yard.

Any ideas much appreciated. Alistair.
Reply With Quote
  #2 (permalink)  
Old 03-29-2016
Senior Member
Join Date: Feb 2014
Posts: 1,562

I bought my 2005 F225 in February 2014 with ~750 hours on it.

I pulled the thermostats for the first around November 2014
and discovered they were packed in wet "salt" - actually tore one apart in order to pry it out
(I had been flushing "religiously" - and the engine rain perfectly with normal temps)

In January 2015 I worked over the inside of the bores with Dremel stainless steel wire brushes and emery paper.

Washed the surface with alcohol, and painted the bore with zinc chromate primer (green aerosol)

Amazon.com: Moeller Green Zinc Chromate Primer Outboard Paint: Sports & Outdoors

I've been checking them every few months - most recently last weekend - and they look great.

Paint is still fully adhered and glossy almost 15 months, ~ 400 engine hours.

So a complete success as far as I am concerned.

I've read that in "exterior" use that zinc chromate needs a top coat -
but it clearly stands up fine "in the dark" - despite ~180 degree salt water.

I'm sure - as with any paint - "preparation" is 99%. I made sure I got down to "shiny metal" before I applied it.

I recall the aluminum corrosion was insidious - the "rotten" spots didn't look too bad, until I hit them with the wire brush. Then what appeared to be "metal" turned into "dust"

This photo would have been during the early stage of the cleanup.

Reply With Quote
  #3 (permalink)  
Old 03-29-2016
Junior Member
Join Date: Mar 2016
Posts: 2
Default Thanks

Many thanks for your feedback, I will have go cleaning them up and apply some zinc Chromate paint.

Many thanks
Reply With Quote
  #4 (permalink)  
Old 03-29-2016
Senior Member
Join Date: Dec 1969
Location: middle Texas coast
Posts: 9,789

When I cleaned up the corrosion on my C40 a hole developed to the block.
I had it welded up from the outside with a high frequency machine by a experienced welder and then used some marine JB weld on the inside so I could shape it to fit the stat back in properly.
He had a lot of problems with the welding due to the type of metal and probably the impurities
Reply With Quote

corrosion, f150, thermostat

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 09:39 PM.

Outboard Parts

Other Forums
Mercury Parts
Suzuki Parts
Evinrude Parts
Johnson Parts
Honda Parts

Copyright 2000 - 2017, Outdoor Network LLC