Where's the speed?

[MNdrifter]

I got out for the 3rd time yesterday. I'm past the engine breakin now so I opened it up WOT.
Speedo topped out at 37mph.
I pulled up Navionics on my iPhone, it said 38mph.

I was getting 8200rpm on both engines.
Water was calm and 57deg. 63deg air temp
Wind was 10mph but I tried into/with wind and only changed top speed by ~1mph.
Full tank. 500lbs passengers. Bimini installed but not extended.
It has not been left in the water yet. Just trailered back and forth.

Any ideas why I'm not going faster?

 

[Glassman]

Just trailered back and forth.

Any ideas why I'm not going faster?

Take it off the trailer.

 

[Glassman]

sorry, it's Wednesday, my mind is elsewhere....

I'm not very familiar with your model, 8000 is supposed to be max rpm How did the engines sound?

According to Boattest.com:
Top speed for the Yamaha SX210 (2012-2013) is 46.6 mph (75 kph), burning 16.4 gallons per hour (gph) or 62.07 liters per hour (lph).

I'd check the seal around the intake grates to make sure you don't have any issue with failing sealant. Assuming, of course, you checked the jets and all is clear, plugs are seated properly.

 

[jcyamaharider]

Also what is your elevation? That makes a difference with the performance of engines.

 

[cozilla]

Plugs seated correctly? Seems low.

 

[Scottintexas]

check your reverse buckets to make sure they are pulling up all the way when in forward

 

[jcyamaharider]

Yep elevation is only 1166 so that wouldn't be too much, maybe a little lose.

 

[MNdrifter]

Take it off the trailer.

That would also explain why the draft was so deep

Lake Zumbro is at 915' right now.
The clean out plugs were fully latched when I pulled out afterwards.
The engines sounded fine but then again this is the only Yamaha I've ever been in and I've only used this one 3 times. If there was something wrong from the start, I might not know the difference.
I'll check the reverse gates. Don't know what to look for on the sealant.

When took a test ride in the same model last fall, the dealer boat also topped out at 38mph. The salesman didn't have a good answer when I asked about it.

 

[octavio3311]

The SX210 has the MR1 engines. I believe they're suppose to rev higher than 8200 rpm's. I think?

 

[Bruce]

Boattest.com shows 46.6 MPH at 8000 RPM. They do not show figures for any higher RPM values so I assume that the version of the MR1 in the 2012-2013 MR1 tops out around 8000 RPM.

Here is the review http://www.boattest.com/boats/boat_video.aspx?ID=2614 on the Test Results tab it shows how fast their test boat was going every 500 RPM.

The MR1s in my 2007 SX230 spin up to 10,2000.

Seems like it must have something to do with your reverse buckets or pumps.

 

[Yochichi]

The SX210 tops out at 8200 rpms. At lease mine has for the last 3 years. I get to about 40ish mph at best with perfect conditions. I live in the same area as MNdrifter. Not sure I have ever gone over 40 on Lake Zumbro but that is due to the traffic on the Lake.

So all in all MNdrifter my sx210 has similar performance. I have never checked my gates to makes sure they are completely clear. I have inspected the sealant and to my eyes it looked good.

If you find a 8-10mph improvement I would be interested in what the solution was.

 

[jdonalds]

I boat at about the same elevation. I hit 42mph easily at 8000 rpm. I can hit 45 alone on the boat but it takes 1/2 to 1 mile to creep up to that speed. 2006 SX210

 

[BoaterGuy]

I could only hit 48 mph where others were getting to 50+. I just changed the plugs this season for the first time and now I'm seeing 50. (At last!)

I noticed that two of the plugs in my port engine looked like the gap was different. I would try changing your spark plugs after you check all of the other things. I wouldnt have thought it was the plugs on my brand new boat either, but who knows what the dealer installed before I bought it??

 

[Julian]

Don't know what to look for on the sealant.

When took a test ride in the same model last fall, the dealer boat also topped out at 38mph. The salesman didn't have a good answer when I asked about it.

Strange that their demo boat wasn't running 40+.

To check the grate sealant, lay down under the boat and look at the leading edges of the intake grates. There should be (black) caulk filling all of the gaps on the leading edges. If there is a hole, or no caulk, this will disrupt the water flow to the pump and make it less efficient. I just found that my starboard pump was missing caulk.....I'll get some pics if I remember on Friday.

 

[Glassman]

That would also explain why the draft was so deep

Lake Zumbro is at 915' right now.
The clean out plugs were fully latched when I pulled out afterwards.
The engines sounded fine but then again this is the only Yamaha I've ever been in and I've only used this one 3 times. If there was something wrong from the start, I might not know the difference.
I'll check the reverse gates. Don't know what to look for on the sealant.

When took a test ride in the same model last fall, the dealer boat also topped out at 38mph. The salesman didn't have a good answer when I asked about it.

Gotcha, all good points.

The post about the spark plugs by RobA could be helpful. I've always been able to tell when the boat needed new plugs.

Just for yucks, have you checked your air filters for oil? That will put a damper on the speed. I yanked mine long ago.

 

[jlcj7]

I have read lots of other Sx210 owners only getting in that range. I can get about 42-43 with a loaded boat, when it is just me i see about 45 maybe 1-2 mph more at time when the water is like glass. You should be getting about another 5mph in my opinion

 

[MNdrifter]

If the engines are making 8200rpm, does that rule out the power side of the problem? If there were plug or filter issues, wouldn't the rpm be down?

 

[Scottintexas]

I don't remember what engines you have, mr1 non-ho, mr1 ho or 1.8l

If your turning max rpms then you should be able to eliminate the engine as an issue and move on towards, sealant, buckets, other although you run out of options pretty fast. maybe your intake grates or not flush against the hull causing some drag? checking the filters and plugs is just easy stuff to rule out.

I would suggest trying to get something to compare it to, the test ride in another boat was the same but jlcj7 was able to do just slightly better,

 

[MNdrifter]

It has the mr1 non-ho. I can't find anything in the owner's manual that says 8200 is max rpm. Just going by boattest.com and @Yochichi it sounds like that is top output.
I called the dealer. They are going to put their heads together and see what they can do.

 

[BoaterGuy]

It could be that his boat just needs some more break in time. How many hours are on it now?