2008 Yamaha P90TXR block

[spankeyis]

P90TXR just replaced the head and rebuilt lower unit. I put the flush hose on it and it is spewing a steady stream of water out the mating surface between the block and new head. After closer inspection you can see a small gap on the block where it looks like someone sanded out a small area. Gap is noticeably larger than the rest of the gasket mating surface. My question is…can I take the power head short block to a welder and fill the surface and get it machined or do I buy a new short block?

 

[spankeyis]

Looking for advice on the repair

 

[boscoe99]

What is the compression for each of the cylinders?

 

[99yam40]

if the head is on the right side of pic, that new head is not flat

 

[spankeyis]

Head in on left side of pic…block is right side.

 

[spankeyis]

The compression is good on all cylinders

 

[spankeyis]

More pics below

 

[spankeyis]

Where the horizontal line is a steady stream of water is peeing out using flush hose only

 

[boscoe99]

if the head is on the right side of pic, that new head is not flat

Understatement of the year.

 

[boscoe99]

Or is it the block?

 

[99yam40]

was there a leak there before you replaced the head?
or was the head warped to meet up to that bad spot on the block?

 

[spankeyis]

Or is it the block?

It’s the block side. Looking at the pic now there is a suspect area just above the triangle shape and below the smudged area.

 

[spankeyis]

was there a leak there before you replaced the head?
or was the head warped to meet up to that bad spot on the block?

I don’t know. The guy said water in the oil. Head was sketchy so I bolted on a new head. I know head is good. Now that it’s on the issue seems obvious. Leaking right and number 3 cylinder. This pic kinda tells the tale. Wondering if anyone and built up the block with Devcon or JB weld and then block sanded a repair? Third pic is closeup of suspect area

 

[brodmann]

My son had a very similar situation on his 2004 90HP Yamaha. His mechanic at a local boat repair shop built it up and machined it down and it's working great now. The stuff he used is called "Belzona 1111". My son actually had corrosion on the exhaust cover and had water leaking into a cylinder. The stuff he used is a steel epoxy. It sealed it up, no water leaks and no loss of compression.
I don't know where you're located, but if you're close to Savannah, GA, I can introduce to this great mechanic.

 

[99yam40]

I did something similar to the exhaust plate on my C40.
But used JB weld marine putty.
You need to use a file to make sure the sealing surfaces are flat and in line with the rest of the surface.
hard to do with the power head bolted on the motor, not much room.

 

[spankeyis]

Thank you all! I’m going to pull the head and build the area with an epoxy I think. I’ll let you know how it goes.