What years were these problems? What was done to correct the problem?

all years.......don't use is the only way to avoid issues!!! They all leak eventually, very quickly in salt water!!!

Pull them and send them to CMI at about 200 hours. The refirb cost is better than the alternitive. They cost $150 a pair to refirb at CMI plus shipping.

I have about 140 hours on mine...no problems, knock on wood. My brother has had all sorts of problems with the headers leaking, but has at least twice teh amount of hours.

One way to help assure no problems is to install drains. These will drain header to an overboard dump so no water remains in header while not being used.

Yes water will flow while motor is running, but negligible on cooling ability.

This WILL make your headers last MUCH longer. Also, do not use 90 degree fitting as shown or aluminum. I am pretty sure the 525's have the ends (towards stern) on the water feed tube already threaded. You'll need an adapter to (std size) to go from what is already tapped into header drain to bring it down to #8 or #10 AN.

Eddie Marine has SS overboard dumps. Easy to install, and works!

Great Idea. Someone should make a kit for this modification.

Is it ok to leave the pink antifreeze in them after winterizing? Or drain that out too.

After all I've read on this issue...drain em!

And yes, the 525's do have the threads on both ends. Great post Bill.

There is a factory mod to remove the bypass hoses and drill the top fitting on the Stb. side. More water goes though the headers. I think it keeps the headers cooler making the the heating and cooling cycles not as extreme. The letter I have says #OM956327 and up. Doug

Do you have any more info on this? Where can I find out how to do this? Thanks.