Water Discharge Where it Should Not

[SommerTime]

I have a 2004 Parker 2520XL with twin 150 Yamaha engines with 1464 hours of operation. Yesterday was running the engines while still in the slip and noticed water being discharged in the correct location and also running, not leaking, out above the cavitation plates. I took the cowling off and this is what I saw.

Has anyone else had this problem?

 

[miketheserviceguy]

Haven't heard of that before from the picture its had to tell exactly where that is. Is that under the top motor cowl or under the side "chaps" for the midsection?
Shoot me a PM if you want with the mod/ser #of the motor and I can send my tech rep a note to see if he has come across it. If it is the midsection it would be a first for me on a 150, I know Suzuki had a pretty bad problem in this area but not common on Yamaha.

 

[SommerTime]

Perhaps this pic will give you a better idea of the location of the hole which is about the size of a #2 pencil

Notice the hole in the center of the pic

I will get the serial number of the motor the next time I am at the boat.

Thanks for your interest.
Capt. Bill

 

[Ludicrous40]

Have these motors been inspected for the exhaust tube corrosion?

This is on top of the powerhead, away from where the majority of that problem occurs, but basically looks like the metal was thin in that location and wore through.

 

[SommerTime]

Ludicrous 40 : I can not answer that question since I depend on my marina mechanics to do what ever is recommended in the way of maintenance/inspections.

 

[TWOBOATER]

Wow, that's some serious corrosion. I have seen similar on some of the mid-range Yamaha motors (40-70HP) where the copper thermostat eats a hole in the block at the t-stat housing from disimilar metals (copper and aluminum) being in close contact in salt water. I can't tell from the pic. where your t-stat is, but it looks like you have 2 holes? These mid-range motors which were otherwise in perfect condition, were junked because the repair costs were prohibitive. Gotta love Yamaha...

 

[SommerTime]

Twoboater: I noticed what looks like the second hole in the pic however, did not notice it when I was at the boat. Needless to say I was upset at the time and maybe didn't notice the second hole, if it is a hole. I am making a visit to the marina tomorrow and I will surely look to see if there are two holes or one. No matter a serious problem.
Will keep you posted if you are interested.

Capt Bill

 

[bigk23surf]

http://www.thehulltruth.com/boating-forum/637829-yamaha-f150-welding-blowhole.html

Looks similar to your issue and same years.

 

[TWOBOATER]

Yep, you have corrosion throught the T-stat passage. It's a crappy design because its in the block casting. To fix it right you have to replace the block, which 9 out of 10 times doesn't pay off, esp. for a motor with 1500 hours on it. I don't understand why Yamaha doesn't use a stainless steel and plastic thermostat. I've noticed some of the Mercs use copper but have not scene a casting failure, yet...

 

[DaleH]

FWIW I've made repairs to engine blocks using marine-tex, but admittedly never to a thru-hole like that.

 

[TWOBOATER]

A mechanic friend of mine has repaired a few of these drilling out the passage a bit and put in a pc. of stainless tubing set in with some JB weld. It is just to get a couple(?) more years service out of them. Yours looks like there's a pretty severe loss of material there so any repair might be difficult. I hear cast aluminum is difficult to get a good weld on it. Sorry I don't have better news for you.

 

[DaleH]

What sucks even more, for Owners of newer Yam OBs, is that it took Yummie YEARS to admit to the previous round of excessive and premature exhaust housing corrosion, and only after Boat/US got involved w/ a class action suit.

 

[Bryan 2530]

That is a common problem for the Yamaha t stat area.

Dis similar metals in close proximity and thin casting cause trouble.

Does your motor have zincs in the head? A little late now but I changed those religiously on my 200s when I had them.