Broken impeller pieces

[bluka43]

My X-press bass boat is powered by a 1998 Yamaha 90 HP. A couple of weeks ago I was out fishing and noticed my water pressure gage was reading 1 lb. I looked back at the tell tale and it was producing a moderate stream. (it seemed pretty normal). I ran the boat as usual and dismissed a serious problem. The next day I decided to inspect the water pump. Upon disassembly I found that 3 of the 6 impeller blades had broken off at the tips. I purchased a complete pump rebuild kit, put it all back together, put the earmuffs on it and ran the motor for a few minutes. The gage pressure was back to normal and all was well. My question is, where did those pieces go? I did also pull the T-stat, valve and spring and saw nothing there. Obviously the pieces were broken the day that I went fishing and the motor ran flawlessly. Should I have to worry about a cooling problem next time I use the boat? I have no water temp or head temp gage, only the overheat sensor. Should I install a gage?

 

[SparkieBoat]

Re: Broken impeller pieces

first off do not wait so long to change your impeller again..do it every few years. I would think that your pressure gauge and over heat alarm will be safe enough..no telling what happened to the pieces..if they were small enough they could have passed through. you could pull the foot again and hook a hose to the water tube and remove the t-stats and flush..then reverse and flush from a t-stat hole.

 

[bluka43]

Re: Broken impeller pieces

Thanks Sparkieboat
Yeah, you're right about changing more often. It certainly is easy enough, and good insurance. After pulling the foot off, pulling the T-stat and hooking up a hose to the water tube to flush, is the T-stat opening the only place for the pieces, if any, to exit? Same for reverse flushing from the T-stat, is the water tube the only exit?

 

[SparkieBoat]

Re: Broken impeller pieces

it is possible it could exit through the exhaust or has already exited.

 

[bluka43]

Re: Broken impeller pieces

Maybe, but you know for me to put it to rest, I'll try your suggestion. And even after that, for at least the next couple of times out, I'll be watching and listening closely for any thing out of the norm. Then and only then will I consider the case closed. And I will be not only inspecting but replacing the impeller every couple of years.

 

[robert graham]

Re: Broken impeller pieces

Same exact motor as mine, and I just replaced my water pump impeller, was surprised and relieved at how easy it was, will change mine every 2 or 3 years from now on. Hopefully those impeller pieces of your passed on out of the system, but it's worth watching for a while. don't you hate stuff like that! Good Luck!

 

[bluka43]

Re: Broken impeller pieces

Yeah, it is good insurance to replace it that often. As I said in my post, I purchased an entire kit which consisted of everything but the pump bottom and top. Reason being is that when I took it apart, the insert that is in the top section of the pump was actually grooved somewhat. I know the impeller was replaced just before I purchased the rig in 2005, but I seriously doubt the rest of the pump was. I think I was on borrowed time. For as easy as the job was, I'll never let it happen again. Thanks Bob!