Twin Yamaha 150 RPM variations

Lowlysubaruguy

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Dec 3, 2012
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I have a new 2017 Wellcraft 262 Sportsman with twin Yamaha 150s both right hand rotation and throttle cable engines not drive by wire if that matters. Engines now have enough hours to tinker a little along with water conditions to WOT full speed operations. Boat hit 50 MPH which was pretty impressive given one of many heres concerns that it would be slightly underpowered. Im happy with its performance loaded and unloaded have had a crew of people and a full tank of fuel and gear on it. What I have noticed is the starboard engine seems to be off 300 to 500 RPM ( lower from the port engine at most speeds I have to trim that engine up quite a bit with more throttle to get the RPMS from both engines the same. I wasnt really concerned about this but a buddy suggested maybe thats not right. At WOT and 49 to 50 MPH starboard engine peaks at 4600 RPMS and the Port engine peaks at 4900 RPMS. Tinkering with trim makes little change performance is good I did notice at speeds between 30 and 50 MPH that there is faint vibration felt that can be smoothed out by slightly trimming the outboards differently. id post a photo or my engines control screen but I cannot get photos to post. I read I may need to post a number of times first? Ill look into that soon. Fuel mileage at WOT and 50 MPH is coming in at 1.4 to 1.6 MPG and speeds between 32 and 38 MPH I see 2.4 to 2.6 MPG if that is info that helps. May or may not be normal but I thought id post in case someone knows for a fact.
 

tpenfield

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Jul 18, 2011
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Could it be something as simple as the throttle linkage on the starboard engine? I.e. the linkage in not adjusted correctly so the throttle is not opening completely?

since it is a 2017 . . . warranty fix?
 

99yam40

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Sep 7, 2008
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I guess these are F150s correct?
WOT RPM on those motors should be closer to 6K , so your props are not what you should have on them yet
Why are both right turning motors?
most twins come set up with one right and one left.
 

Lowlysubaruguy

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Dec 3, 2012
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I like the idea that the throttle cables slightly missadjusted. Im optomistic the fix if there is one is simple. I sent an email to the shop I bought it from and they are ready for me to bring it in any time. Which is great. I do have two other minor things that ill have them address while its there.

As far as why both engines are right hand drive. I think the cost difference between a pair of rights or a right and left is fairly substantial these days. Fact is if this is normal performance or nothing that?s what youd call detrimental im fine with it its performance is actually better than I had hoped for. One of my biggest concerns was that this boat might be underpowered with 150s and for a fact it will do everything I need it to do. Would I like to have a pair of 250s hanging back there yes. One thing I decided when I bought this boat was if the 150s did not do what I needed id sell them quickly and upgrade however thats not even a concern It does everything I need it to do. Inm very happy with this boat and its powertrain. I would imagine theres a variety of reasons why left and right rotating powerplants would be prefered but theres probably about $10K difference in cost to have this. I know 250s were going to ad $25K to the price.
 

99yam40

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Sep 7, 2008
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Motors that are not propped correctly will lug the motors all the way threw the RPM range.

Make sure you tell the dealer what your WOT RPM is when loaded and unloaded, maybe he will make it right for you with no or very little cost

I guess I do not see why a lefty would cost so much more than a righty
 

Lowlysubaruguy

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Dec 3, 2012
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I had a hard time grasping why 75 more hp per OB was going to cost so much more. These 150 s are the break point it seems. Big money between them and the next step up. I think they sell a ton of them so the price is a lot less not the case with left hand rotation less made means mo money. They seem eager to fix it if it can be fixed. Nice boat no complaints here. I shopped for a long time. I had just gotten off a striper at the boat show walked into the next building and knew this boat was exactly what I wanted. No one else did though it sat at the dealer for 6 months.
 
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