High water pressure & low water temp

[texasvector]

no worries Jeff. glad yall were having a good time in the tank.

Pete.... I've pulled it out and checked the spring. looks like it's " seating off" until you press the spring. when I had the block hanging in garage I reach up underneath it and pressed the back of the popit to open it. spring seemed to work. there's a " bypass" channel running from small end to big end and it's wide open to dump. is this correct?


thanks for the help guys I think I'm close but not content yet..... rebuilding this thing again is not on my bucket list
sorry not really familiar with the poppit system.

15+ at Wot isn't enough???

[njj502]

15+ probably ok. My tell tale is plumbed into the line from top of the block to the poppit

[transomstand]

15 is ok, rather see it closer to 20. My main concern is your midrange, 8-10lbs at 3-4000 is borderline, 12 lbs is usually considered minimum at that rpm. Just seems like your leaking it out someplace not to be able to keep the block full. As they stand, your numbers are ok, but you've got no "fudge factor", a blade of grass across the water intake could cook the thing.

[texasvector]

anyone plumb the tell tale straight out the top exhaust plate. not tee'd anywhere just straight out. keeping t stat hoses and tell tale separate so you can keep an eye on things.

where else besides the poppet could the water be dumping??

could the wrong base gasket let water fall out bottom?

[transomstand]

I rarely use the telltale as an indicator, the pressure gauge is my bible, and a whole lot easier to look at running 90

Anywhere you dump water from will contribute to reduced pressure, I doubt a wrong base gasket would contribute to low pressure, but a failed one certainly could.

[texasvector]

lol I turn around and look behind me all the time going 90.... usually pulling skiers!

I inspected every gasket from top to bottom yesterday. bottom side of water pump to head gaskets. I do think I was losing water around the exhaust divider gasket.

might try a new poppet valve and see if I see an increase in pressure.

[H20WKD]

Need some guidance….
Just put a 2013 200XS Opti on the Grandsport.


Got 7-10psi water pressure & 90-100 degrees on the SmartCraft @ idle-700rpm, mid range & wot pressure & temp ok.
Not getting hot enough to open the stats. More than a little concerned as we have 15-25 min no wake run to open water after launch.


Tested stats they both open @ 145.
New poppet. No debris, tears or damage noted, It is sea-weed season around here but I didn’t see any evidence when changing the valve, although there was one tiny speck on the port stat.


Can I backflush the poppet by-pass passage by removing the brass fitting on the poppet cover? Air pressure or water?
I did fish a small “snake” 8-10in down the passage when I changed the poppet, but couldn’t get it any further.

Any other ideas appreciated.....


Bob

[XstreamVking]

On the opti's the smart gauge temp is a average readout of all 3 temp sensors. Compressor, star head, port head.The compressor running cool will make the ga read cooler than the heads actually are. On my opti's I run an old style puck sensor in each head with an either/or switch to flip between them and display on an analog temp guage. Also, you have a comp coolant fitting/screen on the port side down low that needs cleaning from time to time. Follow the hose from the comp to it.

[vnemous]

my 300x runs head temps around 160 and water temp via smart craft is around 111 when running 105 at idle. Water pressure never more than 10 lbs at wot but its volume with a 3.0 JMO

[H20WKD]

V-King, vn ....thanks for the comeback...

At idle my Fluke IR reads 90* +- 5* at the stats port & starboard. I checked the compressor screen before changing the poppet, strong stream, cool 'cuz it's directly from the pump.
Both the VDO & SmartCraft gauge's are within a few degrees of one
another.

IR temps at the base of the plugs range from 106 to 122, again at idle on the hose.

The stats do have a bleed-by notch and the weak stream there is barely warm.

During the run out from launch she runs pretty lumpy, just not getting up to Temp.

Bob

[H20WKD]

From studying the flow chart....is it possible to clear the discharge passage at the poppet by either back-flushing thru the plug on the small side of the valve or one of the thermostats?

Bob

[XstreamVking]

You might try replacing the spring on the poppet. That controls the opening point. Supposed to be 9#'s of pressure before it opens if I remember correctly. Back flushing from the t-stats should put water down the poppet dump. Way over 9#s of pressure.

[H20WKD]

According the the shop manual the only cause listed for high pressure @ idle, cold temps, is plugged poppet discharge (dump?) port. I have cleaned the poppet cavity and installed a rebuild kit.

When I did the poppet on our 225x after sucking weed there were twigs & seeds everywhere.
I have seen no evidence here 'cept the tiniest speck at the port stat.

Was thinking of using a hand pump at the port stat.

Bob

[bigboy]

According the the shop manual the only cause listed for high pressure @ idle, cold temps, is plugged poppet discharge (dump?) port. I have cleaned the poppet cavity and installed a rebuild kit.

When I did the poppet on our 225x after sucking weed there were twigs & seeds everywhere.
I have seen no evidence here 'cept the tiniest speck at the port stat.

Was thinking of using a hand pump at the port stat.

Bob

Did the new poppet fix your problem?

[H20WKD]

Did the new poppet fix your problem?

Well not entirely....have had the damn thing in/out half dozen times.

One problem I found...the plunger that the diaphragm attaches to was bottoming out on the plastic seat in the block causing the diaphragm to remain slightly open when the cover was tightened down. Took about 1/8" off the end of the plunger that attaches to the diaphragm, then stretched the spring 3/4".

Idle pressure now 3-4psi @ idle. 100* on the SmartCraft.
3000rpm 22psi 40 mph. 98*

Will be calling Merc Perf again, let them know what I found and see if they have a solution. It's running so cold the stats never open.

Bob