1996 Dt 55 water pump parts question.

[tidechaser 1]

my 1996 Dt 55 has been overheating when running at speed after a few minutes..i replaced the water pump impeller as it was chewed,replaced the housing and friction plate gasket..but i can put the ears on it and sometimes it seems ok..but still might be getting a tad hot..one day later i tried it again with the ears and nothing came out of the tell tale or the exhaust overflow port!
i put it in the water and it seemed ok..but i suspect it has a leak somewhere as it overheated after a couple of minutes on plane..i had just changed the t stat.
one thing i noticed parts wise..in the water pump parts list i see the small tube for output with the seals..but in my manual it shows a shorter larger diameter tube the goes over the drive shaft and looks like it has seals like the smaller tube. is this something missing to my engine?
i think when i had the weird intermittant pumping issues start was after i replaced the housing as it was badly worn and chewed up the impeller. ????

 

[99yam40]

Re: 1996 Dt 55 water pump parts question.

Chewed up impeller is probably up in the passages and plugging things up.
May be hard to get it all out, but pulling Stat and lower unit and hooking a hose to tube may flush things out

 

[tidechaser 1]

Re: 1996 Dt 55 water pump parts question.

Chewed up impeller is probably up in the passages and plugging things up.
May be hard to get it all out, but pulling Stat and lower unit and hooking a hose to tube may flush things out

thanks..that was what i was thinking and the mechanic says that is not likely considering what symptoms we have seen..we did flush it but did not remove the t stat.
i still think there are pieces in it..he say we would have to remove the powerhead and tear it down to properly clean it out. he thinks there must be air or exhaust getting into the water pump..could be as it seems to do better with the boat in the water but not on plane. except..i have seen it on the flush not pumping..hmm.

 

[99yam40]

Re: 1996 Dt 55 water pump parts question.

I have heard of exhaust getting into water pump if there is a lot of corrosion down around that area in lower unit dividing the two.

Also make sure your motor is not mounted too high and is sucking air because of turbulence on plane

 

[tidechaser 1]

Re: 1996 Dt 55 water pump parts question.

yes..we checked for corrosion..very little..looks good..and it is a long shaft so it is actually a bit low.
thanks.