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  1. #1

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    How do I increase RPM's

    I just installed the R&D velocity stacks and air filter along with a Riva FF exhaust on my 2006 fx ho. After the install I was running about 10,250 RPM's at WOT. However, after I installed a new wear ring and a Solas 14/20 impeller my RPM's dropped to about 9800. Is there anyway that I can increase my RPM's to get a little bit more top end speed without repitching or changing my impeller? I remember reading on one of the threads here that upgrading to the CR9EK plugs will get me a bit more horsepower and increase my RPM's but I'm a bit weary about installing plugs other that what the factory recommends (yes I'm a greenhorn). Any suggestions?


  2. #2
    Kristian Keppel Waterholics's Avatar
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    First of all you need an accurate RPM gauge. No way you're turning that much RPM.

  3. #3
    I think they do turn that much RPM..... Prop Pitch is the only way I know.

  4. #4
    Monkeytunk's Avatar
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    10250 !!??

    Yeah that can't be right, unless, you are running over 100 mph...

  5. #5

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    The stock 2008 and earlier yamaha fx ho's have the rev limiter set at 10,500 and they consistently run at 10,200 at WOT. Yes the RPM's are high but that's how yamaha designed them to run. Keep in mind, this is the MR1 engine which was initially introduced in the yamaha R1 motorcycle in which the red line was set at 14,000 RPM's so 10,500 on the fx ho is about 30% less than the motorcycle. It's a definitely designed to be a high reving engine. Here's are 2 links to websites that list the specifications for my ski. Scroll down and you will notice that it states (horsepower RPM 10000) http://www.personalwatercraft.com/sp...gh-output.html. http://www.yamaha-motorcycles.org/20...ictures-specs/

  6. #6
    Site Admin Green Hulk's Avatar
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    His RPM's are correct for his year/model ski


    Sbaird4000, there are two ways to increase RPM
    1) Increase power output of your engine
    2) decrease pitch of your impeller.

  7. #7

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    Green Hulk, are there any bolt on modifications (other than what I've already installed) that you know of which I can add to increase the power output of my engine ? Thanks.

  8. #8
    Quote Originally Posted by sbaird4000 View Post
    Keep in mind, this is the MR1 engine which was initially introduced in the yamaha R1 motorcycle in which the red line was set at 14,000 RPM's so 10,500 on the fx ho is about 30% less than the motorcycle.
    I've seen this a few times floating around this site. (I'm a little bit of a R1 nut as i've had an R1 for the last decade and follow all the changes of that bike).

    The MR1 was first introduced in what, 04? Bore/stroke of 76x58. This sounds like it's based off the pre-04 R1 engine. The 03 R1 engine has a bore/stroke of 74/58 as opposed to the 04 which is 77x53.6 (higher revving engine, but the 20 valve head got dropped in 07 in favor of a 16-valve head). The 03 R1 makes peak power at 10,500RPM with a redline of 11,750. And it's 13,750 on the newer 20 valve engine. Stock the bike literally falls on its face ~11k RPM until you modify intake/exhaust. The only point of the revving to 11 is grab another gear and drop you back into the power peak.

    Yamaha says the peak power on the MR-1 is at 10,000. Which makes sense for the increased bore. So basically what i'm saying, is you're riding around with an engine that'd most likely go ohh a valve yum yum yum chump chump if it revved past 12.

    In other news - I got 45,000 miles on my R1 engine and the valves were still within spec. when checked last summer. Such a great engine and it's been around since 1998. I had a buddy with 100,000+ on his 99 R1 with no serious engine issues.

  9. #9

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    Quote Originally Posted by sbaird4000 View Post
    Green Hulk, are there any bolt on modifications (other than what I've already installed) that you know of which I can add to increase the power output of my engine ? Thanks.
    It's cheaper to pitch your prop.

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