Loss of power

[joshuam.garza]

So, I just did an oil change and plugs on both engines (2015 At 210). Pre-maintenance I topped out @ 42 mph 8,000 RPM, and starboard engine randomly would bog. Post oil change, boat runs amazing, no bogging, no weird noises, runs like a top. But...my speedometer is way off now, AND I top out at 35 mph on my gps (speedometer shows 28 mph). Please tell me someone has some insight on this??

 

[djetok]

So, I just did an oil change and plugs on both engines (2015 At 210). Pre-maintenance I topped out @ 42 mph 8,000 RPM, and starboard engine randomly would bog. Post oil change, boat runs amazing, no bogging, no weird noises, runs like a top. But...my speedometer is way off now, AND I top out at 35 mph on my gps (speedometer shows 28 mph). Please tell me someone has some insight on this??

Fist thing would be check to see if the oil is not overfilled. Check your air filters for oil on them. This would be the fist indicator of a overfill.

 

[joshuam.garza]

Fist thing would be check to see if the oil is not overfilled. Check your air filters for oil on them. This would be the fist indicator of a overfill.

I’ll check those filters. I only put 2 qts in each engine and they were right on full. Doesn’t mean I didn’t mess something up though. I will check again.

 

[joshuam.garza]

Ok, so air filters showed no signs of oil or blow by. I did lower the oil levels to just about 1/2” above low (as opposed to right on full). Took it out and this time topped out at 37 mph on the gps & showing 28 mph on the speedometer. The only thing I did was change plugs, and I gapped them all between .75-.8 mm. At full throttle I’m getting 8200 on port side engine & 8000 on starboard. Engine rpm’s better after oil & plug change. Just the power and speedometer have me baffled.

 

[HangOutdoors]

Isn't the speedo a wheel under the boat? I am not sure in your year. In my AR210 it is a spinning wheel. Anyhow, check to make sure that it is gunked up and in proper working order. Check the impellers. Do you have fins? Check those, maybe something got bumped as well as make sure that the gates are opening up full when in the forward throttle position.

 

[djetok]

Ok, so air filters showed no signs of oil or blow by. I did lower the oil levels to just about 1/2” above low (as opposed to right on full). Took it out and this time topped out at 37 mph on the gps & showing 28 mph on the speedometer. The only thing I did was change plugs, and I gapped them all between .75-.8 mm. At full throttle I’m getting 8200 on port side engine & 8000 on starboard. Engine rpm’s better after oil & plug change. Just the power and speedometer have me baffled.

You probably had it over filled. Just remember to put back , the same amount removed. I always filled it low , and then on the water (level engines) I top off to below full.

Is there anyone in the boat. Also the further forward people sit, the slower you will go.

The speedo could have a wheel spinning issue, but they are never right. Not that far off though. The biggest deal is your rpm. Yours are right. Just make sure when comparing speed , make sure its apples to apples , like same fuel, number of people and where they sit.

On the bogging, check caulking on your pumps and intakes. That could be cavitation.

Also do you do wet storage or dry storage. Your hull having algae will slow it down.