2018 18 TRX Lost Top End Speed

[barmour]

oops, disregard

[barmour]

Understand, what steps should a competent mechanic do to ensure WOT, you mentions throttle plate clearance, TPS, throttle % acceptable is what % and does motor even need to be running to determin WOT? tks

[EuropeanAM]

WOT Position and TPS position can be checked without starting or running the engine. Physical position (WOT) is checked visually, and the TPS position is checked on the G3-CDS (for 100% throttle position).

Some information on the physical position check is provided in the FAQ Section under "Hotfoot Setup".

[barmour]

I mistated in post, I set/measured ptp by leveling deck then measured from rear most bottom of v pad to floor then leveled cav plates and measured center prop nose to floor and subtracted diff to set ptp

[barmour]

Don,
I measured the belt tension pully with touque wrench and it cracked at 70 inch pds just shy of the pully stop point.

[EuropeanAM]

As long as it clicks BEFORE contacting the stop, it's likely fine (this is not a "book" specification, had to test numerous new and known-good setups to provide the info).

If you're really close to the end, might not be a bad idea to purchase a spring and a belt (install, and keep the old belt in the boat as a spare).

[barmour]

Regardless of PTP from 3.75 to 2.5, regardless of 25p new prop or 25p Croxton 25p, with just me, full gas, empty livewells, and my normal fishing gear, the best speed gps via lowrance or VV was 66 mph and rpm WOT via vessel view was 5480-5500 at it's highest rpm, water psi WOT 22-24 psi.

[EuropeanAM]

Don,
Thinking about this random port thermostat alarm that's happened at idle at times. I think this alarm since boat was new is the problem that's maybe caused the port side to lose/cause the power/rpm drop, but don't know how to confirm it other than a piston compression checks when warm. I don't see how it could be 2 bad thermostats, especially when there was not even a grain of sand nor grass in the thermostats and more inclined to think it's maybe a blockage of water flow in the port side during idle that after a while caused power output issue from the port side. This being the only alarm I've gotten since boat was new, and still sometimes alarms maybe has/is causing the power/rpm loss? Thoughts?

First and foremost: How are you determining (specifically) that you are getting a "Port Side Thermostat Alarm"?

There is NOT any "Port Side Thermostat Fault". Simply a THERMOSTAT FAULT (and it means that at least one bank failed to come up to operating temperature after idling for 5 or minutes without acceleration, after startup).

Thermostat faults (like several dozen other faults that sound the same horn sequence) can result in Engine Guardian becoming active, which reduces your available power, depending on the situation.

IF it happens to be the same thermostat- it's far more likely that you have debris in it (very rare that we see a thermostat that is actually "bad" as in "defective").

[barmour]

First and foremost: How are you determining (specifically) that you are getting a "Port Side Thermostat Alarm"?

There is NOT any "Port Side Thermostat Fault". Simply a THERMOSTAT FAULT (and it means that at least one bank failed to come up to operating temperature after idling for 5 or minutes without acceleration, after startup).

Thermostat faults (like several dozen other faults that sound the same horn sequence) can result in Engine Guardian becoming active, which reduces your available power, depending on the situation.

IF it happens to be the same thermostat- it's far more likely that you have debris in it (very rare that we see a thermostat that is actually "bad" as in "defective").

ok tks

[barmour]

I replaced the port stat.

[SilverFox579]

Have you checked this by pointing a heat gun directly at the suspect thermostat cover when the condition exists? Like Don said, there's no "port (or starboard) side thermostat" alarm. Where are you getting this information from?

Thermostats begin opening at 130°, so "warm" may not be hot enough. If engine coolant temp doesn't reach 120° in 5mins you will get the thermostat fault Don mentioned above. At home, are you running the engine on muffs or in a tub?

[barmour]

A few months ago was running motor on muffs when pulled the dump hoses, and didn't have a temp gun then but VV said was 120 I think. Last summer the boat place shot temp laser at the stat housings and I saw them opening and closing between 120-140

[EuropeanAM]

Have you checked this by pointing a heat gun directly at the suspect thermostat cover when the condition exists? Like Don said, there's no "port (or starboard) side thermostat" alarm. Where are you getting this information from?

Thermostats begin opening at 130°, so "warm" may not be hot enough. If engine coolant temp doesn't reach 120° in 5mins you will get the thermostat fault Don mentioned above. At home, are you running the engine on muffs or in a tub?

Barmour- Phil meant to say an infrared temp gun, I believe. Looks like you understood that.

There are no "some three beep some six beep" alarms. Your engine has two (2) alarms:

SOLID TONE: Critical warning. Turn engine off as soon as is safely possible and get to dealer for service.

Four beeps, Pause, Four Beeps (may repeat): Non-Critical Fault. Return to port and get engine in to dealer for service.

GUARDIAN can be active and not see a Guardian "Fault". The only time Guardian "Faults" show is if you attempt to exceed the "Available Power Threshold" that the PCM has assigned.

Hypothetical Example: There is a piece of wood stuck in your port side thermostat (which incidentally is a real possibility). Engine is started and IDLES (with no throttle input) for 5 minutes, Port side only reaches 96 degrees F. A "Thermostat Fault" is set, and a NON-CRITICAL warning sounds, warning you to turn around and head back. Engine GUARDIAN is now likely active- and in this case may limit you to 60% available throttle. Unless you advance the throttle to 61% or higher for approximately 6 seconds, it is unlikely that a GUARDIAN fault will be seen in the Freeze Frame History.

Thermostat Faults: There is no differentiation in the fault as to "which" thermostat. The ONLY way to tell is to look at the Freeze Frame data and see what temp is being reported on each bank.

Wood and debris is moderately common in fishing applications. Many of the anglers I've found that were having repeat debris problems were actually picking up debris either at weigh-in (beached), while launching or loading on a debris-laden ramp, OR WHILE TROLLING AROUND IN SHALLOW WATER WITH STUMPS OR LOGS.

In the later case- simply getting in the habit of tilting the "big" engine up out of the water made a DRASTIC reduction in the number of problems they were having.

See if you can get a printout or saved file of the Freeze Frame (Fault) History and the Run History. I'd be happy to review them for you (G3, Diacom, or CDI/Meds).

[SilverFox579]

Barmour- Phil meant to say an infrared temp gun, I believe. Looks like you understood that.

Oops and you are correct Don.

[EuropeanAM]

Hey man- you're entitled to at least 1 a month.

[SilverFox579]

My fingers don't always listen to my brain.

[fly by night]

My fingers don't always listen to my brain.

Maybe you are simply getting senile Mr. Phil, if so join the club! LOL

[barmour]

All I can say about the alarms is it's a mix of 3 beeps at times and other times it's more than three beeps but never a steady beep. I will say I'm confident it's not typical weed & debris from the lake alarms. If it was i'd hear other optimaxs around me in similar water beeping like mating calls and the intermittent rash of alarms in clean water goes in spurts ie...sometimes alarms in first 5 min, then most other times no alarms for 20+ min and other times lots of alarms in 30 min in clean water. I didn't have a laser temp gun at the time, but the tech did shoot his at the stats during tub idle and as he tests more said he can email me run/alarm results later. I'm trying to let him do his job and just update results if he finds the problem. While I understand the front water intakes are more prone to debris intake, I don't believe this many intermittent alarms over a 3 year span are related to lake debris. I'm pretty good at tilting my motor up when needed. It's either a bad sensor or if it's a valid alarms, then a water flow issue or part defect in the motor since it was brand new IMO. Sometimes after a 20-30 min idle, the alarm scares the shoot out of me when it goes after (kinda like your alarm clock when sleeping). Other times it seems to go off several times in a 30 min period and i didn't shut the motor off during that time, sometimes no alarm for a 15-30 min idle. Not only is it embarrassing, just sucks and with the top end issue, makes it suck more. The tech & I discussed replacing the driver side tstat since I put a new one already in the port side in the fall, maybe I got the wrong side, we'll see.

[EuropeanAM]

See if you can get your hands on the PRINTOUTS of the Run History and Freeze Frame (Fault) History. The engine PCM has been recording the faults that were occurring, and that info is sitting there in the PCM, just waiting to be accessed for diagnostic purposes.

If it were me, I wouldn't so much as turn the key to the start position until I had the information from the two printouts (let alone try further diagnostic steps).

Just had one leave here yesterday that had been having a similar situation, Freeze Frame showed 345 (that's THREE HUNDRED FORTY-FIVE) Thermostat Faults had occurred, the most recent of which had limited the engine to 83% available power (via Engine Guardian). So yes... it's possible, that just as was the case here: One piece of wood 1/2 the diameter of a #2 pencil, trapped in the Port-side thermostat, could potentially cause the entire problem. Can even happen to a NEW thermostat... the very first time it opens.

[barmour]

So I've had the tech verifying stuff and so far these are items he's checked and found good.
-fuel rail/fuel system pressure
-air pressure/reeds
-compressor
-piston area inspection w/light & camera
-piston compression
-full throttle physical and 100% WOT on CDS tool
-had the port head cover replaced because I or the last crap mech in colorado did checking compression mis threaded a plug while chasing this top end problem when I replaced the plugs.

In short he's not found a smoking gun yet to fix. He thinks maybe the misthreaded plug might have caused the issue since now some plugs were fouled. I told him the new head will not fix anything unless it was bad before mis threaded the plug and only replaced the plugs chasing the top end/rpm loss.

Can you guys think about a few other opinions on my 2 issues:
1) The temp alarm I've been getting since motor new in May 2018 to Mar 2021, since motor had 5 hrs to now 90 hrs. It's only when idling and the 2 stats and the long plastic filter in the passenger side of motor are "NOT CLOGGED" as the cause. The alarm says low temp on the port side per the tech and my vessel view. I highly doubt the brand new motor had a bad stat and the new stat I put in is another bad stat. The stats and filter have been inspected multiple times and it's not debris. It does seem intermittent but regular enough. It seems to me either a bad sensor or if not a bad sensor, something inside the motor but not a bad stat. Also the Tech asked me if I wanted him to clear out all alarms and I said yes, he cleared alarms and I ran the boat for another week in TX and I heard at least 25 of the same idling alarms and he said there was only one occurance/count of the low temp alarm.

2) Boat has never registered before nor right now with any guardian modes.