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10 hour oil change speed decrease

I'm hopefully going to be able to finally get my boat in the water tomorrow. I will see if I can snap a few pics for you of my plugs. That's the only thing left that I can think of with so few hours on the boat, other than the oil levels and/or something in the intake.

Cleanout plugs seated nicely? Dragging a butt load of water in the bilge? Flat calm, I know I was able to reach mid/high 40's with no issues, only me and the wife on board AFTER the oil change. This is a head scratcher
 
No water. Barely a ripple. What RPMs do you get upto?
 
can't rightly remember, that was months ago. I haven't had my boat in the water since last year. I had projects that had to get done prior to a party, and I knew the second I took the cover off the boat, all motivation and desire to get work done would go right out the window, and get lost in my wake ?
 
Not to be a conspiracy theorist; but is there any chance they have programmed something in the ecu to limit rpm until a 10 hour oil service “event” is marked complete by a YDS input (forced dealer visit?)
 
The owners manual page 173 does not have you change the oil filter at 10 hours.
Unfortunately I did not see max RPM offered in the engine specifications table, so user input or more digging to get that.
 
Not to be a conspiracy theorist; but is there any chance they have programmed something in the ecu to limit rpm until a 10 hour oil service “event” is marked complete by a YDS input (forced dealer visit?)

It is something that I thought about, but I don't see mention of it anywhere on this forum let alone on the internet so I would think that it would have come up and at least come out by now and been verified.

@Seadeals Dealership change oil filter at the 10 hour. Also since you are breaking in the engine and it is getting that initial wear first, it is good to get out as much of that oil and particles as possible including what the filter is collecting.
 
This is a strange one. Have u ran WOT since u installed the thrust vectors? Maybe slightly off creating a bit of drag? Only other thing I can think of is bad fuel.

You can try this...after I adjusted my throttle linkage so there is no gap to the stop, I hooked the water up and cranked the motor (turned water on after starting the motor, of course). I SLOWLY advanced the throttle wide open (if you advance too fast, the RPMs don’t accurately register) and made sure it hit max RPM and it did...8000. I only did this twice cause I’m not a fan of running the motor that hard on land but it was only for a few seconds.

Something of note, however, I took the boat on the water the next day and I could only hit 40 mph and motors maxing out at about 75-7600 RPM. I definitely chalk this up to wind, current, and chop.
 
Did you say you have thrust vectors installed? Make sure you nozzles are aligned and pointing straight. Also, make sure the TV lifts up easily with no binding and clears the nozzles opening. What does the jet wash in the rear look like? Compare with others who posted here what theirs look like. This is one test I still need to do. Just trying to think outside the box with you here.
 
@ZGhost No I don't have thrust vectors, I have Cobra Jet Steering his newest model. And I have checked those repeatedly the nozzles are aligned.

What is bizarre, is that I had 8 people in my boat today, and I could only still hit 7200 RPM, but the speed GPS verified was still hitting 37.4 mpg. Which was very surprising since I was carrying another 500 lbs. or so. very light wind. I am still very bothered that the RPM's won't go any higher, but I am extremely pleased that I didn't lose any speed and power and acceleration were still there and we pulled tubes with 1-3 people on them no problem.

I am going to look at the throttle linkage again tomorrow once I have recovered from being out in the sun all day.
 
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Glad you were able to enjoy the day. I know you said air filters were fine but I would be interested to eliminate an air restriction for sure by running one of the two engines without the filter and comparing max rpm. I also get the logic of replacing the oil filter at 10 hours and understand dealers are doing it; but want to share since at least 2006, replacement of the oil filter is not a part of the 10 hour check per Yamaha tech data.
2. What fuel are you running? Any additives?
3. Any feel of cavitation, anomalies or recent work on the pumps of any kind?
4. What rpm did you see prior to the oil change?
 
@Seadeals Ok I will pull an air filter, per your recommendation to compare and see what I get next time out.

I did see in the manual and elsewhere it was not mentioned to do at 10 hours, replacing the filter. I spoke with the 3 dealers in Michigan that I can find and they just order and use the Yamaha kit which includes the oil and filter and change the oil filter at 10 hours. I am curious how that would affect RPM's though.
I am not running any additives.
No cavitation, everything is smooth. I don't feel any loss of power. Hole shot is fantastic as well. I looked down and up under into the impellers and they are clean.
I was at 7800 RPM's both engines before oil change. Well probably 3hrs or so before 10 hours, I didn't run WOT for about the last 3 hours before the oil change due to heavy chop and rolling waves on Lake St. Clair.

I do have another question! On the hose is it safe to WOT on one of the engines to check Max RPM's? Or should this only be done in the water? I have only reved it to about 3000-3500 quickly and briefly to push water out after flushing on hose.
 
I definitely do not recommend running the engines that high on the hose and personally only flush at idle or no wake rpm. There is even debate on the forum whether or not the engines should be reved after shutdown to blow out the water boxes as the manual states. Your situation is extremely puzzling, so I am sorry for your frustration. I am glad it isn’t keeping you off the water so it is important to not do anything risky that would change that as you troubleshoot. As it is new, you also should consider making this your dealer’s problem and not compromise warranty in any way. For most that is usually a pain and a long wait; but you also didn’t pay for these headaches or sign up to be a mechanic on a brand new boat.
 
A friend just had an issue with his Moomba (6.2L Raptor). He put some gas in it that had water. It was enough water to warrant return to the dealer (an hour and a half away) to sump and check out, which is exactly what he requested they do. Several days later the dealer called talking about the engine codes and stating they are opening a warranty claim for a known issue on that model year wIth the cat converters. He asked if they got the water out of the tank and they hadn’t even done that. Given he was trying to burn water, I suggested he reaffirm to them they need to address the water removal immediately and that ECM codes were from pumping a mix of water and fuel (of course the emissions ratios will be off and throw codes). Another week later they called again and said he should come work for them as a mechanic because they did what he said and everything was now running perfectly with good gas. I just feel like many dealers try to push the menu of known problems on you when you go in without listening or intelligently troubleshooting your problem.
 
Here's my conditions, 5 people on the boat, zero problems with how it feels to me. You can see the rpms aren't matching, but both throttles are pegged, and there wasn't a sound or "feel" difference in speed until the tach's read 7200 rpm's. Depending on straight line or turns, I was hitting 37-45 on the speedo

IMG_20200607_162011161~2.jpg
 
@drewkaree Great Info. It looks like you are turning more RPM's on the both engines than I am. the engine on the left looks like what I was getting before. Either way I cant get over 7200 which would be the first has mark past 7.
Going to do some more testing this week.
 
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My top speed is 48.5 and the boat is going in for it's 10 hour tomorrow. I'll let you know if anything changes afterwards.
 
That's a great speed, but you have 1.8's I do not. Nice boat. Although if it does decrease there could be a theme.
 
@Seadeals Thanks for the additional input. I do agree that it may have to go into the dealer at some point, I am just trying to eliminate or perhaps rectify anything that I can, before I lose my boat for 2 weeks give or take which is what two of the dealers that are within driving distance are projecting since they are backed up with all the boats sold and routine maintenance.

All in all, it seems like they are simple engines and sop for operation. Oil correct level and viscosity, throttle linkage adjusted accordingly, air filter no oil in them, spark plugs gapped correctly, nothing in the impeller, jets aligned, keep the ladder up and locked (won't get into that one), Adjust weight in back. etc.
 
The fastest my 2019 AR210 has ever gone is 46MPH, and that was registered by the boat dealer in their pre-sale checkout. It now routinely sits at 40 (5 people, gear, full tank, tower speakers, anchor, extra battery, etc etc.

I'm at 1100 ft elevation...
 
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