Junk in the poppet valve... again!

[tlwjkw]

think hes referin' to how fas tha coolin' water exits tha motor.. no restrictions ta slow it down enough ta do its job...

[powerabout]

think hes referin' to how fas tha coolin' water exits tha motor.. no restrictions ta slow it down enough ta do its job...

he said it was stuck closed not open hence the pressure goes up

[tlwjkw]

have no idea what he means by "excessive coolant speed" means then...........

[rjdubiel]

with the poppet stuck closed the motor is not passing enough water, the temp climbs.

[WaterZebra]

you can do it one time and still get junk moving around for days, weeks without strippin' it down and cleaning EVERYTHING THATS GOT A HOLE IN IT.....

Agreed. Anything with a pocket or passage could be the cause. Start with the heads first followed by the exhaust splitter (bolt on / bolt off). Careful with salt impacted bolts or you will have far more work to do than planned! Lots of compressed air too!

[DieselDood]

have no idea what he means by "excessive coolant speed" means then...........

It's an assumption on my part.

in an Automotive application, if the coolant speed through the motor goes to fast, it can't transmit the heat from the motor to the coolant before the coolant exits the motor causing it to overheat.
So even in a race car there is either a thermostat or a restriction to slow the coolant down.

[DieselDood]

Agreed. Anything with a pocket or passage could be the cause. Start with the heads first followed by the exhaust splitter (bolt on / bolt off). Careful with salt impacted bolts or you will have far more work to do than planned! Lots of compressed air too!

The motor has 30 hours on it after a rebuild last winter. And lucky for me... being in the great white north where the air hurts our face 9 months of the year... No salt! LOL

I'm going to clean the poppet again and hopefully I can get through the end of the season before I rip it down for cleaning and inspection.


I'm just amazed that I'm having so many issues with this. BUT... if this stuff can sit in places and ride along before giving me issue again, then... well that's probably what's happening.

I'm surprised that with as much water pressure as the motor builds (easily pegs the gauge), that when the valve gets stuck, it doesn't blast the other crap out before I take the poppet out get it cleaned and try running it again.

[Whaaaaat]

Could you have the wrong spring in the poppet? Think the HP motors that ran poppets also ran a stiffer spring. Too stiff of a spring may not open enough to let the smaller trash pass easily.

[tlwjkw]

It's an assumption on my part.

in an Automotive application, if the coolant speed through the motor goes to fast, it can't transmit the heat from the motor to the coolant before the coolant exits the motor causing it to overheat.
So even in a race car there is either a thermostat or a restriction to slow the coolant down.

understand how all that works but you can't have a "blockage/closed poppet" AND water exit to fast to cool........ maybe i jus misunderstood what ya said?

stuck open will heat at low speed. water moves too fast... stuck closed will heat at high speed.. not fast enough.

[tlwjkw]

Could you have the wrong spring in the poppet? Think the HP motors that ran poppets also ran a stiffer spring. Too stiff of a spring may not open enough to let the smaller trash pass easily.

think tha springs are all tha same......

[DieselDood]

understand how all that works but you can't have a "blockage/closed poppet" AND water exit to fast to cool........ maybe i jus misunderstood what ya said?

stuck open will heat at low speed. water moves too fast... stuck closed will heat at high speed.. not fast enough.

I thought with it being closed and high pressure that the water was still making it's way through to fast. When it's stuck, it's indeed stuck closed, so it makes sense at high speed it runs warm.

[WaterZebra]

I thought with it being closed and high pressure that the water was still making it's way through to fast. When it's stuck, it's indeed stuck closed, so it makes sense at high speed it runs warm.

Take the poppet out and run it and see what happens?

[DieselDood]

I will have to try that another time. I have a tourney tomorrow night, so I pulled it apart and found a sandbox.

[powerabout]

coolant flow speed going too fast is old wives tale.
Exit restrictions are either to build pressure or temp or both.
on an auto you need pressure to stop the pump cavitating at high speed.
check out the wp nascar engines run at..

[David - WI]

coolant flow speed going too fast is old wives tale.
Exit restrictions are either to build pressure or temp or both.

Yes, it's a myth... but I didn't want to fight this battle.