10 hour oil change speed decrease

[HangOutdoors]

I just did my 10 hour oil change. I siphoned out about 3.125 quarts from each engine. I put back in exactly 3 quarts so I could check the oil on the lake today when I know I would be perfectly level. The oil on both engines was midway between F and L.

Today on the lake, I noticed I was running WOT at 7100-7200 rpm and I was not getting over 35 mph. Before I was hitting 7500-7600 rpm and I hit just under 43 mph. I ran for a couple of hours and then I checked the oil while in a calm patch of water in a cove. Same thing. Half way between F and L.

I used the Yamaha Engine Oil Kits from my dealer. I purchased 2 when I picked up the boat.

What could be going on? I didn't do anything else to the engines but oil change and filter.

 

[HangOutdoors]

Anyone have any thoughts? Or run into something similiar?

 

[suke]

Current, winds, smoothness of the water, fully loaded with fuel/supplies/people all can affect the top speed.

 

[HangOutdoors]

Thanks, I was aware of that reading other threads. Same exact two people with same gear, sitting in same location, no wind on glass water, same lake. Temperature of water was -1.1 degrees from original test. Same full tank of gas, Bimini not deployed. I did this on purpose to make sure everything was the same. Some members indicated that they achieved more after 10 hour. I was just looking to hit about the same. RPM's and speed are now lower.

I am wondering if I should change the plugs and air filter as well?

 

[ZGhost]

Did you just do an oil change or did you also change plugs?

I bet it’s the 0.125 qrt you didn’t make up ?

no, just messing with you @HangOutdoors, do a few more test runs before making a final conclusion.

 

[HangOutdoors]

Just oil and oil filter.

 

[zipper]

Sounds like a plug issue. It is only 10 hrs since new. At the very least I would check the spark plugs gaps with a feeler guage, there could be a couple out of spec. A plug change may be in order.

 

[HangOutdoors]

I changed out the plugs today. Won't be able to get her out to test till most likely the weekend. Here are the pictures of the original plugs that came out. I am no mechanic, how do they look? Gap was off on 1 from each side as well but not by alot.

 

[BeauSko]

Hmm this is something I’m gonna have to keep an eye out for. I’ll be doing my 10 hour service after my next outing. Just out of curiosity, why did you change the oil filter? I ask bc the owners manual doesn’t say to at 10 hours.

Those spark plugs don’t look bad enough to cause a drop like ur talking about.

Did u use the same octane gas on this fill up?

 

[HangOutdoors]

Everything i read indicates to do that, plus you will have metal shavings and other things in the oil and filter. The yamaha kit i bought came with the filters and yamalube oil.

Different gas station base octane

 

[BeauSko]

Everything i read indicates to do that, plus you will have metal shavings and other things in the oil and filter. The yamaha kit i bought came with the filters and yamalube oil

Cool, good to know. I’ll do the same. Hope ur next run shows improvement!

 

[Gym]

Bet your air filters are saturated with oil. Take them out, run with no filters you should see a big difference. I think your oil reservoir was overfilled.

 

[HangOutdoors]

No, I checked the oil filters they are dry and clean. Have checked oil on trailer, in lake before running, after an hour or so in lake and back at the house. I measured exactly what I took out of each engine and put back in slightly less, as others have done. Oil sits halfway between F and L on the stick.

I also checked the throttle linkage to make sure it was fully extending and additionally that the buckets where raising up all the way.

 

[Sugarcharged]

No, I checked the oil filters they are dry and clean. Have checked oil on trailer, in lake before running, after an hour or so in lake and back at the house. I measured exactly what I took out of each engine and put back in slightly less, as others have done. Oil sits halfway between F and L on the stick.

I also checked the throttle linkage to make sure it was fully extending and additionally that the buckets where raising up all the way.

Hey HangOutdoors. Any updates? I'm following your experience with the AR210 (beautiful boat by the way!!) since I'm deciding between AR195 vs. AR210 in the near future. I'm looking to reach 40 mph in a constant basis and don't need more than that, however, don't want to be in the mid-30s. Very interested in the AR210 due to its advantage with twin motors and better mid-range for watersports. Thanks a lot, just curious and wishing that your boat is back to high 30's to low 40's mph.

 

[HangOutdoors]

None as of yet. I didn't have a chance to get back out on the water this last weekend. I changed the plugs and made sure my throttle linkage was all set as well as the opening and closing of the buckets. I will also check speed via GPS as well. Plan on going out this week. I really like the boat.

 

[HangOutdoors]

Got out on the water this evening on Cass Lake and the chop was pretty sizeable. It was rough so I couldn't get the boat up to full speed. Was towing the kids around for a few hours but the engines felt like they were running smooth. Will check top speed hopefully on next outing.

 

[drewkaree]

Any fogging oil used on it? I wouldn't have thought so, but...?

Alternatively, I would think it would come down to conditions and/or possibly an overfill. Mine "gained" speed after having the correct (ie not overfilled) amount of oil.

I have fogging oil to burn off next weekend, so I'm just guessing, no personal experience with that yet.

 

[HangOutdoors]

Yes no fogging oil. Oil level is good right between the marks mid way. Will run WOT in the next couple of days.

 

[HangOutdoors]

Ok Today I had 1/2 tank of gas. Bimini Top down. Oil level is good, 1/2 way between marks. Almost a perfect calm. Me and one other person in the boat. No gear. 38 mph top speed at WOT on Connect, 36.1 on GPS. Could not get over 7200 RPM. Both engines running right at 7200 RPM. I checked the APS thing on the side in the engine compartment and both sides are hitting the stop firm, with no gap.

Any other thoughts? I feel like I am missing 500-600 RPM at the least.

 

[drewkaree]

You aren't dragging your anchor? ?