I'm going to try and make this as concise as possible. Need some help from a motor guru familiar with optimax / 200XS 15".
The poppet valve has always been strange and mysterious to me. My knowledge of these motors cooling system is pretty much limited to the fact that water cools them, lol.
Problem: Motor sounds continuous alarm and enters guardian mode (limits to 4000rpm) when idling. Condition is hopelessly intermittent. It began sometime in mid-June, subsequent to hitting a submerged log at 25-30mph; a hard hit. Bent the prop and jammed wood into speedo pitot tube so far it had to be nearly drilled out. Found no wood in sport master inlets however.
I thought I had this fixed on 4th of July when I replaced both t-stats owing to one of them being quite sluggish and not opening fully. It was fine all these weeks;; no alarm anymore then last weekend the problem returned with a vengeance.
Here are the symptoms and observations:
1. Works fine on hose in driveway at all times. Computer shows block pressure at 7.6psi at idle, on hose. Dash gauge however shows 3-4 psi.
2. Water pump new in late May, all the way from baseplate to housing. (this was before problem began.)
3. Pees a 5-foot laser beam from tell-tale regardless of alarm or not - shows strong pressure at least there.
4. Overheating is never an issue. WOT for miles is around 148F; idles at 120F.
5. Other obvious guardian mode issues that would cause it to alarm have been pretty much eliminated (low oil/bad sender in oil tank, overheating, etc.) Unless I do not have a full listing of what can cause guardian mode to be entered. Remember this ONLY happens while idling. Motor runs great at idle AND at speed.
6. Went through removal of skirt, cleaning out screen that feeds compressor cooling water, straightened out kink in water line that dumps t-stat feed into midsection, no dice.
7. Yesterday the problem was once again at its worst, so I tried to key in on all observations and circumstances. Observations: If your crack the throttle open and start the motor, holding a fast idle (say 1,000rpm) it will never alarm. Drop back to regular idle (650?) and BEEEEEEEP!!!! Continuous and nothing will shut it up.
8. ECU logs NO related faults. W.T.H.
9. I noticed two things yesterday have never noticed up til now. Dash water pressure gauge reading. When motor is started, seems like takes forever to come off zero and reach 4 psi or so. Yet it pees hard almost immediately. During this delay, the alarm may trigger. The other thing: When coming off of high speed (when you get 20 psi pressure owing to the velocity) the gauge drops to ZERO. ZERO?!? That cannot be right. It never comes up again - or at least takes forever. And yes, still a strong pee stream...always a constant and never varies.
So my question is this: Will a stuck poppet valve with wood or debris in it account for these symptoms? Mainly after coming off high speed, if it sticks will this result in low water pressure to the block and/or gauge?
Will someone who knows please offer suggestions?
THANK YOU - stumped here (pun intended).
The poppet valve has always been strange and mysterious to me. My knowledge of these motors cooling system is pretty much limited to the fact that water cools them, lol.
Problem: Motor sounds continuous alarm and enters guardian mode (limits to 4000rpm) when idling. Condition is hopelessly intermittent. It began sometime in mid-June, subsequent to hitting a submerged log at 25-30mph; a hard hit. Bent the prop and jammed wood into speedo pitot tube so far it had to be nearly drilled out. Found no wood in sport master inlets however.
I thought I had this fixed on 4th of July when I replaced both t-stats owing to one of them being quite sluggish and not opening fully. It was fine all these weeks;; no alarm anymore then last weekend the problem returned with a vengeance.
Here are the symptoms and observations:
1. Works fine on hose in driveway at all times. Computer shows block pressure at 7.6psi at idle, on hose. Dash gauge however shows 3-4 psi.
2. Water pump new in late May, all the way from baseplate to housing. (this was before problem began.)
3. Pees a 5-foot laser beam from tell-tale regardless of alarm or not - shows strong pressure at least there.
4. Overheating is never an issue. WOT for miles is around 148F; idles at 120F.
5. Other obvious guardian mode issues that would cause it to alarm have been pretty much eliminated (low oil/bad sender in oil tank, overheating, etc.) Unless I do not have a full listing of what can cause guardian mode to be entered. Remember this ONLY happens while idling. Motor runs great at idle AND at speed.
6. Went through removal of skirt, cleaning out screen that feeds compressor cooling water, straightened out kink in water line that dumps t-stat feed into midsection, no dice.
7. Yesterday the problem was once again at its worst, so I tried to key in on all observations and circumstances. Observations: If your crack the throttle open and start the motor, holding a fast idle (say 1,000rpm) it will never alarm. Drop back to regular idle (650?) and BEEEEEEEP!!!! Continuous and nothing will shut it up.
8. ECU logs NO related faults. W.T.H.
9. I noticed two things yesterday have never noticed up til now. Dash water pressure gauge reading. When motor is started, seems like takes forever to come off zero and reach 4 psi or so. Yet it pees hard almost immediately. During this delay, the alarm may trigger. The other thing: When coming off of high speed (when you get 20 psi pressure owing to the velocity) the gauge drops to ZERO. ZERO?!? That cannot be right. It never comes up again - or at least takes forever. And yes, still a strong pee stream...always a constant and never varies.
So my question is this: Will a stuck poppet valve with wood or debris in it account for these symptoms? Mainly after coming off high speed, if it sticks will this result in low water pressure to the block and/or gauge?
Will someone who knows please offer suggestions?
THANK YOU - stumped here (pun intended).
