10 hour oil change speed decrease

[minn19]

Why would you be nervous as long as the oil within proper parameters?

I like having a safety margin and not being on the minimum of really anything. Plus if you are running the motor hard while turning/bobbing around on wakes etc.............it’s piece of mind there will be enough oil covering everything when doing those maneuvers.

 

[HangOutdoors]

The safety is already built into the oil level. If turning a boat hard or going through rough chop would alter the engines ability to get oil within parameters, there would be a lot more issues out there. I have spoken with a competition Jet Ski racer and they keep their engines just above L and never any issues or oil problems and they get tossed around a lot. He felt the RPM's were abnormally low and that is how I began this journey with my OCD for the last couple of weeks.

I do subscribe to the belief that whatever makes you feel better do it, I get it.

 

[minn19]

Was there significant air temp and humidity changes from your pre 10 hr to post 10hr? IE your first 10 hours were in the spring in 60s and 70s and dry air, and now it’s summer time with 90s and high humidity?

As it gets hotter and more humid the density altitude climbs, so even though your lake might physically be at 1000ft above sea level, the characteristics of the atmosphere around you are actually several thousand feet higher, leading to a performance decrease in the motor.

My knowledge of this is mainly from turbine aircraft, you can easily see a 5-10%+ decrease in power/rpm in the summer, but those engines are spinning at 40,000rpm, compressing and exploding shit tons of air, not sure if that’s a fair comparison to a piston engine.
I know drag cars and nascar motors produce less power when it’s hot out. I’m not really sure how much this would effect a small boat motor.

Might be a factor, might be some useless knowledge from me.

Drag racers are obsessed with DA and you see a lot of hero times on prepped tracks coupled with super low DA days. Auto manufacturers love to test their 1/4 times in these conditions for marketing even though very few of their customers would be able to obtain those advertised times.

That being said he should still get the full RPM, the engines won’t makes as much power in hot/humid conditiins at full RPM compared to the cooler/lower humidity days.

I know I love taking my supercharged Camaro out on crisp 50 degree or so mornings, just gotta watch that rear traction though when colder.

 

[HangOutdoors]

Sunday is the day. Low humidity, 68 degrees, water temp will be 10 degrees higher than original test and everything else is within spec.

 

[minn19]

The safety is already built into the oil level. If turning a boat hard or going through rough chop would alter the engines ability to get oil within parameters, there would be a lot more issues out there. I have spoken with a competition Jet Ski racer and they keep their engines just above L and never any issues or oil problems and they get tossed around a lot. He felt the RPM's were abnormally low and that is how I began this journey with my OCD for the last couple of weeks.

I do subscribe to the belief that whatever makes you feel better do it, I get it.

Yup it’s all up to what we are each personally comfortable with. I hope it solves your issue, but I’m obviously skeptical it will and don’t see it as a great long term solution to the issue.

 

[BeauSko]

Was there significant air temp and humidity changes from your pre 10 hr to post 10hr? IE your first 10 hours were in the spring in 60s and 70s and dry air, and now it’s summer time with 90s and high humidity?

As it gets hotter and more humid the density altitude climbs, so even though your lake might physically be at 1000ft above sea level, the characteristics of the atmosphere around you are actually several thousand feet higher, leading to a performance decrease in the motor.

My knowledge of this is mainly from turbine aircraft, you can easily see a 5-10%+ decrease in power/rpm in the summer, but those engines are spinning at 40,000rpm, compressing and exploding shit tons of air, not sure if that’s a fair comparison to a piston engine.
I know drag cars and nascar motors produce less power when it’s hot out. I’m not really sure how much this would effect a small boat motor.

Might be a factor, might be some useless knowledge from me.

Nice outside the box thinking. Very true. When I was working on my private pilot’s license, this was a very important factor u had to take into consideration for takeoff (need more runway to takeoff with higher density altitude).

 

[HangOutdoors]

"I know I love taking my supercharged Camaro out on crisp 50 degree or so mornings, just gotta watch that rear traction though when colder. "

Brings back memories... The Fall leave early from school I was 17 on the country roads in my Camaro (non supercharged), then after that my Mach I.... Good Times. Simpler times.

@minn19 You may be right. But when I spoke with the Dealer Service he even recommended that I retest the boat and make sure everything is in order before I bring it to him, that way it would check off a lot of boxes and questions. The list he gave me was the same suggestions everyone else had given me on the forums.

1) Throttle Linkage (RPM and Speed)
2) Jet Alignment (Speed)
3) Oil Level (RPM)
4) Weight (Speed)
5) Filters Air (RPM)
6) Spark Plugs (RPM)

 

[minn19]

"I know I love taking my supercharged Camaro out on crisp 50 degree or so mornings, just gotta watch that rear traction though when colder. "

Brings back memories... The Fall leave early from school I was 17 on the country roads in my Camaro (non supercharged), then after that my Mach I.... Good Times. Simpler times.

@minn19 You may be right. But when I spoke with the Dealer Service he even recommended that I retest the boat and make sure everything is in order before I bring it to him, that way it would check off a lot of boxes and questions. The list he gave me was the same suggestions everyone else had given me on the forums.

1) Throttle Linkage (RPM and Speed)
2) Jet Alignment (Speed)
3) Oil Level (RPM)
4) Weight (Speed)
5) Filters Air (RPM)
6) Spark Plugs (RPM)

I was hesitant in even bringing up my opinion as I didn't want to add another thing for you to think about. I'd just hate to see something bad happen, which I doubt it will trying this. I used to race motocross (amateur) and I'm guessing the jet ski racing scene is no different. They are willing to try different things to get that last bit of advantage of speed on their competition and if a motor blows so be it. It still sucked to fix, but nothing compared to fixing it on a brand new boat like ours. I'm guessing you are keeping yours for a long time like the rest of us so I'm coming at it from the longevity side of things. I track my Camaro a few events a year (again very amateur), but I still over prepare to the point my friends give me a lot of crap about it. But, I like bringing everything home in one piece. I'm getting too old and don't have the time to mess with the headaches when stuff really breaks anymore.

Any way, that is what is behind my point of view. I am curious to hear what the results of this will be as in all of my days of doing stuff like the above, I've never heard of any proper oil level preventing an engine from hitting redline/top RPM for a motor. But, I do realize I definitely don't know everything, especially with boats so I'm here to learn like the rest of us.

 

[anmut]

Update: no speed increase or decrease yesterday after the 10 hour. Ran the same w/ top speed of 48 (wife loaded)

 

[HangOutdoors]

Did testing about an hour ago. Similiar conditions, a bit more chop. Oil a half inch above low after 8 minutes of running checked on water. First pic is with air filters in, second pick without air filters. Same run each time. Into the wind i lost 2mph but rpms held same. Found 500 rpms on port and about 250 rpms on starboard. Max speed was 43.5. I am pleased again.

 

[BeauSko]

I took mine out for a spin today as well. Damn near identical numbers as yours. 2 adults, 2 kids, standard eqpt load. There is a couple hundo difference in RPMs between motors just like yours. Pics r screenshots of a video I took.

 

[buckbuck]

So is the differing rpm due to the different loading on the impellers?

 

[buckbuck]

I believe that is why on my boat they provided two differing impeller pitches.

 

[drewkaree]

Update: no speed increase or decrease yesterday after the 10 hour. Ran the same w/ top speed of 48 (wife loaded)

What does your wife being drunk have to do with this? I mean, if it helps add speed, I'm willing to bartend!

 

[anmut]

What does your wife being drunk have to do with this? I mean, if it helps add speed, I'm willing to bartend!

LOL “wife loaded” = everything packed you could need for a three day trip that’s actually just six hours.

 

[HangOutdoors]

We went out on Lake St. Clair today. Definitely a bathtub. When I found some water that was somewhat decent I hit 41 mph, RPM's the same, full tank of gas. Yamalube Additive added. 4 adults 3 children 30 gallons of water, 4 more gallons in the Porta Potti, 2 coolers, Ice, Wine Food some clothes. Bimini down.

Very pleased with the boat and performance. I am no longer having the issue.

 

[Gym]

We went out on Lake St. Clair today. Definitely a bathtub. When I found some water that was somewhat decent I hit 41 mph, RPM's the same, full tank of gas. Yamalube Additive added. 4 adults 3 children 30 gallons of water, 4 more gallons in the Porta Potti, 2 coolers, Ice, Wine Food some clothes. Bimini down.

Very pleased with the boat and performance. I am no longer having the issue.

So, incase I missed something what was the fix?

 

[ZGhost]

We went out on Lake St. Clair today. Definitely a bathtub. When I found some water that was somewhat decent I hit 41 mph, RPM's the same, full tank of gas. Yamalube Additive added. 4 adults 3 children 30 gallons of water, 4 more gallons in the Porta Potti, 2 coolers, Ice, Wine Food some clothes. Bimini down.

Very pleased with the boat and performance. I am no longer having the issue.

So what’s the conclusion? did you change something you believe fixed the issue? Or was it just a matter of making few more test runs?

 

[HangOutdoors]

Well i am unsure since i went through and tweaked everything again. Plugs removed again verified gap minor adjustment on one of them, snugged upthrottle linkage. Changed jets by eigth of inch. Put gas in from different gas station, added yamalube additive. Brought oil down a bit to under half full. Verified airfilters visually and by running and testing with and without.

So everything is right were it should be. Perhaps as i think about it doing one at a time and testing would of provided exact issue and resolution. Was obsessing over it too much though to get resolved.

My plan next week is too bring up oil level to half way and check, then to three quarters and check since i have a baseline now that appears repeatable. I was running yesterday for about 6 hrs all around the lake.

 

[Rockfords Fosgate]

Out all day on Friday. Touched 45 with 3 people (loaded down boat), but sat around 36 with 9 on board. RPMs 7400-7600.