Changes to Promax water routing

[ActivatedSludge]

My 2000 Promax has no hose running from the top of the block to poppet. I have seen others run that way. The thermostats dump port side to telltale, starboard side to the adapter.

My question is why did Mercury start installing plugs? Wouldn't the poppet hose to the top of the block help with warming the block?

Trying to help get to temp in Michigan cold water. (New thermostats, impeller, and poppet kit)

Kurt

[Go Time]

I would put it back stock.

[90 5.0]

I would put it back stock.

Some of them came that way? I had one factory(or so I thought ) that was like that. I never ran it that way I yanked it all and ran it like my other promax was.

[Go Time]

I dont think they ever came that way, but I've been wrong before. The normal hose routing for the steel 2.5s is the same on all production motors. One hose from poppet to top of block and a hose from stbd thermostat to port then to tee that goes to tell tale & adapter plate.

[ActivatedSludge]

All 3/8 i.d. hose?

[90 5.0]

That's what I use on mine iirc

[Go Time]

The tell tale maybe 5/16, but everything 3/8 will do it. Make sure you have the tell tale nipple on the end. The small hole in it helps.

[ActivatedSludge]

It makes me question why they changed it? It's plumbed like a 225x. I had one that was like that. Maybe because it is a 2000, close to the end run of production?

[90 5.0]

The one i had like that was a 2000 also

[ActivatedSludge]

My factory service manual shows the 2000 model plumbed the traditional way. The poppet to the top of the block, starboard to port to the adapter with a tee to telltale.

[tux974]

My factory service manual shows the 2000 model plumbed the traditional way. The poppet to the top of the block, starboard to port to the adapter with a tee to telltale.

This is the safe and proper way and is the way I would personally suggest to do it.
If you look closely at those 2 split "T" you have 3/8 and 5/16 nipples for a reason.
The reason to dump from popet to top of the block is to help heat up the block.

[ActivatedSludge]

This is the safe and proper way and is the way I would personally suggest to do it.If you look closely at those 2 split "T" you have 3/8 and 5/16 nipples for a reason. The reason to dump from popet to top of the block is to help heat up the block.The top tee or lower to the adapter/telltale has the 5/16 and 3/8? Which side gets the smaller opening?Thanks!

[ActivatedSludge]

Hose size?

[Go Time]

3/8 on all three nipples on top tee. Bottom tee is 3/8 from top tee & to adapter, 5/16 to tell tale.

[tlwjkw]

My 2000 Promax has no hose running from the top of the block to poppet. I have seen others run that way. The thermostats dump port side to telltale, starboard side to the adapter.

My question is why did Mercury start installing plugs? Wouldn't the poppet hose to the top of the block help with warming the block?

Trying to help get to temp in Michigan cold water. (New thermostats, impeller, and poppet kit)

Kurt

one piece or two piece adapter plate?.. really a ProMax power head or pre 89 production power head?.. jus somethin' ya gotta ask nowdays......

[ActivatedSludge]

one piece or two piece adapter plate?.. really a ProMax power head or pre 89 production power head?.. jus somethin' ya gotta ask nowdays......

2 piece, 2000 promax

[tlwjkw]

gottcha..... might wanna do it this way then....


My factory service manual shows the 2000 model plumbed the traditional way. The poppet to the top of the block, starboard to port to the adapter with a tee to telltale.

i'm like most, never seen anything like that even on production motors after '89... all later had tha hose down to tha poppet including any PM's i've had, been around..... but it is Merc, soooooooooo!

[Steve Pope]

The hose from top of block feeds water to the dump side off the popet valve to cool the exhaust in the mid until the popet valve opens. It has no effect to engine operating temps.