Where's the speed?

[MNdrifter]

The SX210 and AR210 have the old 1.0L mr1 engines. No supercharger, no turbo. Normally asperated 110HP each. All other boats have a variant of the 1.8L engine.

 

[OrangeTJ]

Depending on conditions (temp), I get 7900 to 8200 rpm out of my 2011 SX210. 8200 RPM equates to 45ish mph on our boat (47 with just me on board and the bimini folded back). "More hours" doesn't make sense to me, as 8200 rpm is 8200 rpm. Only thing that makes sense to me is something interfering with the pumps moving as much water as they can at that rpm - sealant gaps, misaligned grates, misaligned gates, damaged impellers, etc.....or a bunch of water in the bilge loading down the boat.

 

[MNdrifter]

There is a lip about 1/8" between the black housing and the white fiberglass above the shaft.
How smooth does this need to be?

http://i1033.photobucket.com/albums/a413/nsmisner/photo3_zps4cad1690.jpg

 

[jetboater4life]

There is a lip about 1/8" between the black housing and the white fiberglass above the shaft.
How smooth does this need to be?

http://i1033.photobucket.com/albums/a413/nsmisner/photo3_zps4cad1690.jpg

It looks like something dented the fiberglass where the shaft comes out of the boat. Here are some pics of mine for reference

 

[MNdrifter]

The white stuff at the very top is a glob of sealant that oozed out around the shaft seal. I didn't want to tear it off in case too much came out. I should trim it back next time the boat is out of the water.

 

[jetboater4life]

I bet that is your problem. It looks like it could disrupt the flow of water. If you are worried about breaking the seal. Have the dealer do it if your boat is still in Rochester.

 

[Scottintexas]

while that could certainly be an issue the fact the boat you took the test drive in last year had the same performance is still puzzling and what I would be trying to figure out the similarities or dis- similarities with other members with the same model.

is your intake grate flush with the hull?
do you have a YDS, maybe the tach is off and your really not turning 8K rpm?

It stinks your not getting 45mph like others but in the long run I would gladly trade it for the other benefits of the yamaha system and accept it. I rarely go over 40mph anyways unless you bought your boat for going fast as one of it's main purposes,

 

[Tom Duignan]

Does anybody know why my starboard engine could be revving at 8000 rpms and the port is revving at 6000 rpms and the boat, (2010 sx210) is going about fifteen mph and won't go any faster. It has been in salt water all season so I'm gonna take it out and power wash hull. Both engines start right up but have check engines lights on.

 

[Cobra Jet Steering LLC]

Do you have trash in your pumps? and check the code for the check engine if it has trash in the pumps it will cavitate so R P M's will be high but speed won't be any good, also check the clean out plugs be sure they are seated properly. trash in the pumps can block the cooling water also.

 

[Bruce]

@Tom Duignan, change your spark plugs.

 

[Cobra Jet Steering LLC]

When you say it has been " in salt water" do you mean you mean sitting in it for extended time because if that is the case I can promise you there is a lot of stuff growing inside the pump intake area and in the pump water intake that supplies the cooling water to the engines.. It only takes a few days for things to start growing inside protected areas and if you have growth on the hull you will have more inside the pump area.

 

[OrangeTJ]

Like CJS said, if it has been sitting in salt water for some time, guaranteed you have stuff growing in the pumps. That will have a massive impact on the efficiency of the pumps. 6k rpm also sounds like you need to replace spark plugs. I hate to say it but these boats are simply not suitable for leaving floating in salt water for extended periods (like a boating season).

 

[davel501]

I wouldn't change the plugs on a 2010+ as a method of troubleshooting. If you are getting 8k on one and 6k on the other that tells me that you have crap in your pumps and that 8k motor is spinning in bubbles. That 6k motor is moving enough water to bring the RPMs down but tons of bubbles there too. Surprised you are not overheating to be honest.

 

[Bruce]

If 6,000 RPMS is the max RPM of one engine then spark plugs are a likely culprit on that engine.

But I also agree that having been in salt water all season that boat likely has a jungle growing below the waterline including in the jet pumps.

 

[Kevin1741]

I had a 2012 ar210 i traded with 20 hours because the top end was only 38 mph.

 

[Tom Duignan]

Do you have trash in your pumps? and check the code for the check engine if it has trash in the pumps it will cavitate so R P M's will be high but speed won't be any good, also check the clean out plugs be sure they are seated properly. trash in the pumps can block the cooling water also.

Thank You,
Taking boat out tomorrow to check the jet pumps. Already checked the clean out plugs and can feel that impellers are clean but I think you are correct about trash inside the pumps.
Thank You so much,
Tom

 

[Tom Duignan]

If 6,000 RPMS is the max RPM of one engine then spark plugs are a likely culprit on that engine.

But I also agree that having been in salt water all season that boat likely has a jungle growing below the waterline including in the jet pumps.

Thank You,
Gonna take it out of the water tomorrow and check the pumps. Probably correct about growth in there.
Thank You
Tom

 

[Tom Duignan]

If 6,000 RPMS is the max RPM of one engine then spark plugs are a likely culprit on that engine.

But I also agree that having been in salt water all season that boat likely has a jungle growing below the waterline including in the jet pumps.

It seems that the suggestion about growth in the pumps in unanimous. Taking it out tomorrow to clean the pumps. While it's out, I'll change plugs also.
Thank You very much,
Tom

 

[Cobra Jet Steering LLC]

You are entirely welcome be sure the water feeds from the pumps to the engines are also cleaned out properly as I am very sure that is why your engine lights are coming on lack of cooling water.

 

[Tom Duignan]

I wouldn't change the plugs on a 2010+ as a method of troubleshooting. If you are getting 8k on one and 6k on the other that tells me that you have crap in your pumps and that 8k motor is spinning in bubbles. That 6k motor is moving enough water to bring the RPMs down but tons of bubbles there too. Surprised you are not overheating to be honest.

I was overheating so I removed the thermostats and that solved the problem of over heating. I think you are correct about crap in the pumps. Checking tomorrow.
Thank You,
Tom