High water pressure 225 promax

**tux974** · 05-27-2020, 04:55 AM

Now that the power head is hanging pull the stat housings and try to back flush system.
From the looks of things I say your issue is elsewhere not in the block it self.
I would redo pump, check water tube, key way, guide tube, grommets etc....JMPO

**Bunger** · 05-27-2020, 09:35 AM

Waiting on gaskets and I’ll get it back together. Also ordered mercury brand poppet spring.

to make matters worse cylinder 2 plug is damn near black while the others are a nice light brown. Could be my not getting over 6k rpms issue. Coil?

**seansbaja1982** · 05-27-2020, 10:22 AM

Tux u mean replace to replace the impeller? I have the same thing going on as Bunger...

**Dave Strong** · 05-27-2020, 10:40 AM

Originally Posted by Bunger

Pulled exhaust divider. Everything looked perfect. A little more carbon/oil/spot on one side compared to the other. Not sure what that’s about. Anyways I’m out of ideas. Is it possible I have the wrong water pump on there?

The 2 different sizes refer to the diameter of the waterpump base that goes into the housing where the o-ring sits. Older cases had a sleeve above the lower driveshaft roller bearing to pull oil up and lube the upper bearing, smaller dia. The newer cases have no sleeve and an oil passage to lube the upper bearing, larger dia. Everything else is the same except if a 3/4 water tube, then the upper hsg is different.

Dave

**Dave Strong** · 05-27-2020, 10:42 AM

Originally Posted by tux974

Now that the power head is hanging pull the stat housings and try to back flush system.
From the looks of things I say your issue is elsewhere not in the block it self.
I would redo pump, check water tube, key way, guide tube, grommets etc....JMPO

If someone installed diverters as a 260 would that cause this?

Dave

**Bunger** · 05-27-2020, 10:43 AM

Originally Posted by Dave Strong

The 2 different sizes refer to the diameter of the waterpump base that goes into the housing where the o-ring sits. Older cases had a sleeve above the lower driveshaft roller bearing to pull oil up and lube the upper bearing, smaller dia. The newer cases have no sleeve and an oil passage to lube the upper bearing, larger dia. Everything else is the same except if a 3/4 water tube, then the upper hsg is different.

Dave

interesting well my base fit super snug so I’m assuming I have the correct one. I read a threAd on another site about a alpha out drive using a very similar water pump that produces a lot more volume. Wonder if that’s a possibility. New one looked just like the old one I took out.

**Dave Strong** · 05-27-2020, 11:00 AM

Originally Posted by Bunger

interesting well my base fit super snug so I’m assuming I have the correct one. I read a threAd on another site about a alpha out drive using a very similar water pump that produces a lot more volume. Wonder if that’s a possibility. New one looked just like the old one I took out.

Not your issue, try flushing as Tux suggested.

Dave

**Bunger** · 05-27-2020, 12:55 PM

Would I be ok to put .75 head gaskets in it? I have a new set of those and the heads are the only things I haven’t pulled off to check. Wondering if I possibly have a combustion leak let’s gas out and pressurizing the cooling system?

**Bunger** · 05-27-2020, 05:23 PM

Here’s the plugs. Dark one is cylinder 2(with 4&6 next to it) other pic is opposite bank. Coils ohmed out correctly. They are new plugs maybe I got a dud?

**Bunger** · 05-27-2020, 05:27 PM

From post to electrode the bad one ohmed 5050ohms while the other 5 ohmed our to 55-5600. Hopefully that’s my issue

**Bunger** · 05-27-2020, 05:32 PM

Left bank with bad plug looks cleaner and more “washed” than the other side. Also seeing Unburnt blue oil puddled up on the clean side vs the black oil on starboard bank.

**Bunger** · 05-27-2020, 07:48 PM

How come the t stat and housing doesn’t have a tiny bypass or hole to vent air and water before it warms up?

**Dave Strong** · 05-27-2020, 07:58 PM

Don't need it.

Dave

**Dave Strong** · 05-27-2020, 08:00 PM

Originally Posted by Bunger

How come the t stat and housing doesn’t have a tiny bypass or hole to vent air and water before it warms up?

had mine out today first time in 2yrs, new waterpump. 4psi at 650 in gear. 10 at 4200, 19 at 6500.

Dave

**Bunger** · 05-27-2020, 08:03 PM

Originally Posted by Dave Strong

had mine out today first time in 2yrs, new waterpump. 4psi at 650 in gear. 10 at 4200, 19 at 6500.

Dave

lucky hahah.

ive flushed everything replaced every gasket other than the heads replaced t stats and poppet. At this point only other thing I can think to try is another water pump. I’m at my wits end