Jump to content
Sign in to follow this  
Bout Time 1

97 yamaha Pro V 150 overheat issue

Recommended Posts

Lately I ‘ve been getting the overheat alarm and then Limp mode only at high RPM, like close to WOT. If I shut it down, wait 30 seconds and turn the key on, the alarm goes off and I can run all day under 4500 rpm. I started out by changing thermostats,  checking the poppet valve (old style) and cleaning it. No change. Recently put a new water pump in. No change. Checked both thermo switches per the repair manual. They are both good. Pulled the heads and checked all water jackets. Some minor blocked areas but have always flushed with ears with fresh water after running in salt. Heads looked pretty good. Cleaned everything up and installed new head gaskets. I also installed the new mushroom style poppet valve. I’m hoping I finLly got this solved but cold and rainy here so no trial run yet. Had anyone had a similar problem? Could it be the poppet valve? I swear the old one looked fine. Thanks. 

PS  this engine has 588 hrs on it  

 

4498B0AF-C401-4BAB-884C-783C5B4BE517.jpeg

2ABBE173-4B67-4A75-91F3-88C5D77190A1.jpeg

CC57DA6E-0BB6-45B8-ACF0-0A653CB678B7.jpeg

AF0DC398-84A4-439F-83D7-51E8C9FFDBBE.jpeg

Share this post


Link to post
Share on other sites

The new poppet is a big improvement over the old style.  Yamahas are very sensitive to blockage in the water jacket passages.  I plastic bead blast the heads and jacket covers to get rid of all the scale and build up.  I also lap the heads flat again.  Try Mary Kate On/Off in a squirt bottle for the passages in the block. use lots of water to clean it all out.  Hopefully your issue isn't a corrosion hole in the exhaust plate mixing exhaust and cooling water.

Share this post


Link to post
Share on other sites

When I bought the gaskets at Atlantic Coast Marine here in Jax I asked about the exhaust plate and the water tube grommet. They said they rarely get that repair into the shop but have done a ton of the poppet valves. I got my fingers crossed. 

Share this post


Link to post
Share on other sites

Had the same engine ,same yr.  It is a great engine,  mine finally died of  water jacket corrosion. I never had a over heating alarm.  Mine was kept in water at a brackish water marina.  Hope yours is ok,600 hrs is nothing for that engine.  Mine had well  over 1500 hrs. You just don't that power sound from the 4 strokes.

Share this post


Link to post
Share on other sites

Had the exact same issue on a previous yamaha.

Replaced everything without solving the problem. Finally pulled the heads, cleaned up the passages, and problem solved. You should be good to go. Mine looked just like yours, which Id consider pretty clogged.

How did it go?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×