2010 ProXS sticky poppet valve

[jboswell]

Hello,

I have a 2010 200 ProXS Serial 1B804175 with symptoms of what I believe to be a sticky poppet valve. Here is the situation.

New water pump this spring (less than 2 hrs on it)
Pulled thermostats at same time as water pump change, verified operation & cleaned
Cleaned strainer at same time as water pump change

Upon first start in the morning I will have 3.4 to 3.7psi water pressure (on smartcraft), good stream from compressor circuit. Motor warms up as normal (rise to 130-140, thermostats open, cools off... usually settles in between 125-130). Run down the lake 3000-4000 rpm with good water pressure (20psi or so), when I arrive at my first spot and idle to into where I plan to fish the water pressure is sometimes at 0.5-0.8psi, stream is weak, motor wont warm up, 65-85 degree engine temps... then eventually (3-5 min or so of idle) it will build pressure up to the 3.5psi and it warms up as normal.

From what I have read this points to a sticky poppet to grommet interface. I have had the poppet disassembled, cleaned it, and verified that the poppet does not slide what I would call freely in the grommet. The poppet is difficult to get started back in the grommet bore once removed and takes some pressure to move within the grommet, however, when reassembling the spring does seem to have adequate force to seat the poppet against the grommet.. I have never had one apart before so I am not sure just how freely this poppet is supposed to slide, it sure doesn't feel like "as buttered" that Don refers to


Yesterday however I fished a small idle only lake (no operation that in the 2500ish RPM range to open the poppet) and the motor exhibited a similar behavior a couple times over the course of the day but corrected itself with sufficient idle time... this didn't make any sense to me as the poppet should not have ever been called to open by water pressure.

I have Rhonda quoting me a poppet rebuild kit but now it has me wondering if I have sluggish thermostats and not a sticky poppet... If anyone has fought a similar problem or sees issues with my troubleshooting please let me know.

In the end I will probably order the new poppet parts anyway, just to be safe and see if the problem repeats after the new poppet and grommet are in place.

Thanks,

Jason

[Savage]

You have a water pump issue, if your pressure is only 0.5-0.8 @ 3000-4000 RPM. I'm surprised this motor is not alarming.

What is your water pressure @ WOT?

[jboswell]

You have a water pump issue, if your pressure is only 0.5-0.8 @ 3000-4000 RPM. I'm surprised this motor is not alarming.

What is your water pressure @ WOT?

sheesh, my apologies ... I screwed up when typing it... after a run when I set down to idle I see the low pressure... will edit to clarify my post above. Water pressure while running is great, 20psi or so. I have not ran down the lake when it was exhibiting the low water pressure issue as the motor is too cold so I dont know if it "comes out of it" at higher RPMs.

[EuropeanAM]

Replace the poppet valve and retest. You've already confirmed (by your own admission) it doesn't slide in and out with "zero" effort, so it is definitely hanging.

[jboswell]

Replace the poppet valve and retest. You've already confirmed (by your own admission) it doesn't slide in and out with "zero" effort, so it is definitely hanging.

Yupper, I ordered the parts from Rhonda today. Should be here in a few days.. I will post back if this resolves it for search fodder :) a few threads matched my symptoms and it appeared the solution was poppet rebuild so I am hopeful.

[Savage]

Agree with the poppet replacement, now that you edited your first post.

[jboswell]

Parts received from Don yesterday. Installed last night.... wow, OK.... now I understand "as buttered"

The new poppet interfaces with the new grommet without friction it seems. The old poppet and grommet required some level of force to slide so I am confident the new poppet parts operate as intended.

On the water test shortly (hopefully today) to confirm that this fixes my issue.

[jboswell]

OK, so on the water test after my last appointment today.... first startup, 3.4-3.6 psi @ idle, motor warms up and settles in around 125 degrees... not bad for 41 degree water I thought. Idle only lake so I idle to my first spot fish and when I fire back up pressure is low at idle but climbs to 3.5 psi within 30 seconds or so and motor warms normally. Long idle to my next spot (20 min or so) motor is holding pressure and temperature fine. Then after fishing 30 min or so I fire up and low water pressure at idle again but climbs to 2 psi or so as I idle out of the area, however, as I idle this time the motor never comes up to temp... 20 min idle back to dock and motor never gets over 70 degrees... ahhhhh

Pulled thermostats tonight, tested them on the stove and then into cold water. Both sides open what appears to be fully and close quickly (10-15 seconds) in cold water. I scrubbed them up good (they were pretty clean because I pulled them and cleaned them this winter as preventative maintenance). Put everything back together and it warmed up correctly on muffs 2.5-3.6 psi at idle and warmed to 138 before settling in at 125 to 129 while on muffs.

I am at a loss, the only thing I can think of is that some tiny particle was holding one open and it dropped out when I fully opened them in 170 degree water on the stove. The thing seems to work now on muffs but I have no confidence it wont act up Sunday when I get to fish again. If anyone has any ideas I am all ears :)

Side note: when I pulled the thermostats they don't seem to be bubble tight, I can seal around the OD with my mouth and blow some air through. When I seal the thermostat poppet with my tongue it is bubble tight (at least to the pressure I can create). Is this typical of a new thermostat or are they bubble tight and I need two new ones?

[Savage]

Thermostat(s) are hanging open intermittently. Next time it doesn't come up to temperature, pinch the thermostat dump hoses closed, one at a time, and see if the temperature rises.

[jboswell]

Thermostat(s) are hanging open intermittently. Next time it doesn't come up to temperature, pinch the thermostat dump hoses closed, one at a time, and see if the temperature rises.

Thanks Savage, I assume that will tell me which thermostat is the issue... though it may be both of them causing problems.

[greeneb]

I would replace both thermostats and be done with it. Especially if they are original.

[jboswell]

I would replace both thermostats and be done with it. Especially if they are original.

From what I can tell they are original.. bolts still had perfect paint until I messed with em this winter. I emailed Rhonda this morning and asked for an invoice for two thermostats and two gaskets. I just want to be done messing with it :)

[Savage]

Thanks Savage, I assume that will tell me which thermostat is the issue... though it may be both of them causing problems.

Yes, the one letting water pass, before the motor achieves 135*F is the bad one.......simple test.

[jboswell]

Update, replaced both thermostats, water pressure 3.4-3.6 psi at idle. Engine warms to 136-140 before thermostats open then quickly settles to 129ish. Did several runs (5700-5800rpm) followed by idling last night and no hint of the original issue. Will play with some engine height changes tonight so more testing of the cooling system in mid 40s water temps but all seems fixed.

It appears that if you pull your thermostats and can blow even a small amount of air through them they are not sealing correctly, my new thermostats were bubble tight where my old ones had a small leak.

[EuropeanAM]