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2006 SX230 HO RPM Max 8,500

Greg__Berger

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Yamaha
Year
2006
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SX
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23
Finally had the boat in the water for several days and got plenty of time to get to know the boat. Two things I wanted to see if I could get some help resolving.
1) Port side throttle would slip back a couple hundred RPM. Found a thread in FAQ on a fix for that. So eager to give it a shot.
2) I supposedly have the HO engines, but WOT RPM is right at 8,500. Is there an adjustment that I should look to make, or where do I start with uncovering potential issues. I haven't opened up the air box or anything yet as I'm hoping there is a throttle stop or something that needs adjusting rather than starting down the line of ruling out mechanical issues. The previous owner changed the oil and plugs at the end of last season as he always did.
 

Beachbummer

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easiest thing to check after replacing spark plugs is to remove the air cover from the engine and examine the air filers, make sure they are yellow and not oil soaked. From there you can check the throttle travel as the throttle body is there next to the air filter. With the boat off, You could put the lever at WOT and see if's reaching the stop, or if there is more to go.
 

Scottintexas

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2) I supposedly have the HO engines, but WOT RPM is right at 8,500. Is there an adjustment that I should look to make, or where do I start with uncovering potential issues.
both engines only making 8500 rpm is unusual, definitely check the oil /air filters but take a picture of the engine label (probably just below the engine hatch) and any engine markings and post them,
 

Greg__Berger

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Will do. Thanks! Boat is in storage, but will grab it soon and take a look. I'll follow up here.
 

vbjoe7

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I’m having the same issue on my 2006 sx230HO. Did you ever find out the cause?
 

Jgorm

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My fx140 non ho would run at 8500 when it was down a cylinder due to a bad plug. It would eventually start firing and get up to 10k after a few minutes of wot. I'd start with a compression test and new plugs.
 

mark_m

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I’m having the same issue on my 2006 sx230HO. Did you ever find out the cause?
Did you recently change your oil and spark plugs? I had this happen to me too... double check and make sure all of the spark plugs wires are fully plugged in. Missing plug classic symptoms.
 

vbjoe7

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Oil and spark plugs were changed at the shop just recently. I did see that they forgot to reconnect one of the leads to the spark plug. The others all looked good and still running at 9000 after reconnecting the lead. Will iridium plugs give any benefit here?
 

Julian

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These engines are very plug sensitive.....getting one fouled causes performance issues. For me, spark is spark...iridium is just expensive spark LOL. First step I'd do is change out the plugs (cant hurt to have a spare set if that wasn't the issue).
 

Scottintexas

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Oil and spark plugs were changed at the shop just recently. I did see that they forgot to reconnect one of the leads to the spark plug. The others all looked good and still running at 9000 after reconnecting the lead. Will iridium plugs give any benefit here?
What elevation are you boating at? elevation can have loss of power,

I doubt iridiums would make much of a difference
 

Chillypilot

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Are you sure you have the HO engines. Should say High Output on the tachs
 

Beachbummer

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Oil and spark plugs were changed at the shop just recently. I did see that they forgot to reconnect one of the leads to the spark plug. The others all looked good and still running at 9000 after reconnecting the lead. Will iridium plugs give any benefit here?
Adding and removing one cylinder should have a larger effect, Any chance the plug has been fouled by all the fuel and non-combustion while it was unplugged? I'd replace that one at least.
 

vbjoe7

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Boating at 5000 ft above sea level. The boat is winterized at this point but I’ll definitely be changing out the plugs and checking the filters in the spring.

I double checked and it is definitely an HO. Thanks for all the responses!
 
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