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09 AR230 Top Speed

MonctonR1

Jet Boat Lover
Messages
49
Reaction score
16
Points
77
Boat Make
Yamaha
Year
2009
Boat Model
AR
Boat Length
23
2009 AR230 and last summer was a solid 50MPH performer now I am barely cracking 43. Nothing has changed in terms of load and conditions. Where should I start looking plugs, jets ...? TIA
 
Change the plugs, easiest thing to do if you haven’t done so yet. Also inspect the air filters to make sure there isn’t oil on them.
 
Change the plugs, easiest thing to do if you haven’t done so yet. Also inspect the air filters to make sure there isn’t oil on them.

Sounds good, worth a try. Any idea what the gap is on the plugs?
 
Gap in mm (in) 0.7-0.8 (0.028-0.032)

if you go with the OEM NGK plugs CR9EB they should be pre-gapped.

other thoughts:
  • your hull may be scummy if you wet slip, that will slow you down.
  • if you have been messing with the plugs make sure all of the coils are plugged in.
 
What RPM are you getting the motors to at top speed?
 
have you pulled the impellers, it's a good idea just to be familiar with the process,
 
Change the spark plugs
Acid wash your hull and then apply a good coat or two of wax
Have you added anything in terms of weight since hitting 50? More weight = more drag
 
Was 50mph on the dream o meter? The stock paddlewheel transducer? I only saw 48.8mph on my 07 with gps. Just asking for a friend. I, I mean he always dreamed of hitting 50. The last outing was 45 with 3 on board.
 
Was 50mph on the dream o meter? The stock paddlewheel transducer? I only saw 48.8mph on my 07 with gps. Just asking for a friend. I always dreamed of hitting 50.
My dream o meter stock paddlewheel hit 52 once (heading downriver on the Ohio River) that’s my story and I’m sticking to it! What’s great is Yamahaul is faster than my brother in laws Chappy that’s running a 5.0 SBC. Our boats seem to run with the 5.7’s.
 
This will also happen if you let the boat sit for the winter and the gas went stale however I usually hear of this in the spring when people are getting the boat out of storage not in the middle of summer.
 
My dream o meter stock paddlewheel hit 52 once (heading downriver on the Ohio River) that’s my story and I’m sticking to it! What’s great is Yamahaul is faster than my brother in laws Chappy that’s running a 5.0 SBC. Our boats seem to run with the 5.7’s.

The SX's are known to be a little faster, due to drag from the AR tower.
 
I have only gone WOT twice since owning the boat and once in the last 13 months. With full load of fuel, gear and family I hit 46.3mph(GPS). I'm sure if I emptied the boat out of any non-essential items and went out by myself I could probably push 50mph.....but why??
 
I have only gone WOT twice since owning the boat and once in the last 13 months. With full load of fuel, gear and family I hit 46.3mph(GPS). I'm sure if I emptied the boat out of any non-essential items and went out by myself I could probably push 50mph.....but why??
I'm with you rarely do I want the 50+ but I just used it as a opportunity to make sure everything is working well. I could tell I was down on power top to bottom as I was likely missing on at least 1 plug.
 
Gap in mm (in) 0.7-0.8 (0.028-0.032)

if you go with the OEM NGK plugs CR9EB they should be pre-gapped.

other thoughts:
  • your hull may be scummy if you wet slip, that will slow you down.
  • if you have been messing with the plugs make sure all of the coils are plugged in.
They were bang on, checked them all and well within range.
 
glad it fixed the problem, another example of how finicky the MR1's can be about plugs,

how old/how many hours did the previous plugs have on them ?

.
 
glad it fixed the problem, another example of how finicky the MR1's can be about plugs,

how old/how many hours did the previous plugs have on them ?

.
Not sure new to me last season first time I change them.
 
Change the spark plugs
Acid wash your hull and then apply a good coat or two of wax
Have you added anything in terms of weight since hitting 50? More weight = more drag
This is something I have always wanted to try-waxed hull vs unwaxed hull. Laminar flow vs turbulent flow.

I have always been told that hulls are better off with a rough surface (e.g. turbulent flow-unwaxed hull) than waxed smooth (laminar flow) hulls.
So do I scuff up my hull for a few extra mph??? $&@? No! Nor will I wax my hull in an attempt to speed her up-to lazy for all that wax on and wax off-that’s a lot of real estate under there!
Does anyone have any practical experience to quell my curiosity with waxing their hulls and getting more mph????

btw 51 mph on a smooth fresh water, calm day WOT by my gps is the best my 2007 AR230 will do!- fast enough
 
Last edited:
I keep my hull clean and don't go WOT but maybe once a season so I have nothing to compare to but others have stated that when they get the algae carpet and other build up on their boat they loose speed and fuel consumption goes up so I'll stick with a clean, waxed hull.
 
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