BF 225 corrosion in the T-Stat housing

[chawk_man]

Pulled my boat for Hurricane Florence. It was ready for a 100-hour maintenance anyway. As an experiment, I pulled the T-stats and hooked up the flushing hose. Contrary to what I have been told and believed, flushing water does eventually get to the T-stat openings. It takes a couple of minutes to get there, and there is no pressure at all on it. It just sort of oozes up there. That's with the T-stats removed.

HOWEVER, if the T-stats are still in place, as in normal flushing, an air pocket will form under the T-stat and that will prevent flushing water from getting there, thus all the corrosion problems in the area for saltwater boaters.

After I buttoned up everything, I got to thinking about how to fix that issue. (Yes, I'm a bit slow at times!) Seems like if you drilled a 1/8" hole in the top skirt of the T-stat, that would allow air to escape and allow flushing water to get to the seating area. A hole that small is not likely to affect the operation of the T-stat.

Next time I pull the boat, will likely try that and see how it works.

Criticisms and comments are welcome.

 

[iang6766]

Bill, you are correct in what you say, however, you still wouldn't get sufficient water flow to adequately clean away the salt, in my opinion there is only one way to flush and that is with engine running using flushers on the pickup. Most of my customers who are pedantic about flushing engines that live in the water have set up something to facilitate getting down to the water pick up to put ears on and I have to say it shows come service time, very well worth the effort. There is nothing more important than good thorough flushing to ensure good longevity in a saltwater environment.

 

[chawk_man]

Ian, on my 225, and many others on this forum have reported, that using flusher muffs on the intakes will overheat the engine. I've tried three different types - single opening round ones, dual opening round ones, and dual opening rectangular ones. All of them leak around the rubber seal. Engine will always overheat. Do you have a recommendation for a type that will get more cooling water in there? Maybe you folks Down Under have bigger water pipes or better water pressure.

Even if muffs did provide adequate cooling, they are impractical for those of us who park our boats on a lift or keep it in the water for extended periods.

One other solution I've thought of is using the flush attachment and goosing the flushing water pressure with an auxiliary pump. Just haven't figured out a practical way of doing that. I would need an additional fresh water supply on the pier. Currently, I have a 3/4" water hose to the pier to my flushing hose and flush after each use for at least 20 minutes. So far I have not experienced serious corrosion issues in the t-stat seats. But many others on this forum have.

 

[xsplicer26]

This is how I flush my motor after every use. I take quick grip and squeeze it very tight on muffs. Of course it is easier for me because I trailer my boat. Works very well.

 

[jrude]

I run my BF90 on muffs before I take it out each time, just to make sure it starts before I drive all the way to the lake. It has not given me problem yet, but it is also a smaller engine. Also my engine may be an exception.

I believe you can force more water through the thermostat port by blocking off the prop outlet. Tape a thick plastic bag tight over the prop flange, and make a very small hole in that bag, so water cannot drain through the hole in the bag, faster than it enters it enters the flush port. Leave the thermostat cover bolts loose so it leaks during flush.

 

[iang6766]

So there are a few ideas, our flushers all come out of th US. My garden hose is only half inch and I have never had my 200 overheat and always flush for 5 mins. Like I said Bill, any flushing is better than none. You probably use your boat regularly which is also a good thing, motors that sit rot a lot quicker in the salt. Interesting discussion nevertheless.

 

[chawk_man]

Xsplicer26 - good idea! Will try that.

Ian - heck, I don't know. Mine overheats on muffs, but it takes about 8 - 10 minutes at idle before the overheat alarm sounds. Maybe I just have the wrong type muffs. And, yes, I do typically use my boat 10 months a year and usually at least every week. The other two months - January & February - it sits on a lift, unless I decide to trailer it to Hatteras for tuna fishing, then as much as weather will allow.

I guess in the long run it's a design issue. My brother has an old Merc 125 2-stroke and it seems to really flush well. He's never had a corrosion problem.