Slowpokedad

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Posts posted by Slowpokedad

  1. Posted

    The rk400 clutch has held up extremely well in all the 120 - 140HP Yamaha applications for sure.    Over a hundred of those being used over the past ten years and I haven't heard of anyone having problems, so that is a pretty good testimonial IMO.

    And in talking with Tony at TMR he cited many examples of use in airboats used for wild rice harvesting where it held up great despite much more abusive use than aircraft.

    I'd put it in a 670 without hesitation.

     

     

    Thanks for your input Yamma-Fox. Just to be clear, when you said that when you spoke to "Tony at TMR he cited many examples of use in airboats used for wild rice harvesting where it held up great despite much more abusive use than aircraft." you are talking about the RK 400 clutch and not the TMR clutch, am I correct?

     

  2. Posted

    The Mohawk sprag clutch failed in the testing phase, so that is out.  As far as the TMR400 mine is working great but I am afraid that Tony at TMR may have passed away and that option also may no longer be available. 

    Thanks for your reply Yamma-Fox. I had noticed that Tony's webpage is no longer up so I wondered if he was still in business. How many RK 400 clutches actually slipped from the Rotax 670 HP? I don't want to fix one issue, only to cause another problem with a slipping clutch, then I'm no further ahead and a with a lighter wallet. I asked Mohawk  about the reliability of the RK clutch and his sprague clutch, and he failed to reply to my questions.

  3. Posted

    Love it on my 140hp yamaha.  Only a few hours on it but its all been under rigorous testing with the new motor setup.

     Engages smooth, runs cool and doesnt slip even under that power and a 79" 3 blade prop.  I can do a 10 min ground run through several engagements and up to full throttle then shut it down and hold my finger on the clutch drum.

    I do like the material and constrution better on my TMR400 version better.  Same clutch but different manufacturer.  Contact Tony at Twisted Metal Racing in canada for that one if you choose.

    I know this is an old thread, but I'm also considering putting a clutch on my Rotax 670. How are the TMR400 clutches from Twisted Metal Racing holding out. Since this is an old thread, you guys using the TMR clutches have more hours on them. I also heard that Mohawk Aero has a sprague clutch for his Yamaha's and can fit the C Drive. I am worried that the RK 400 clutch doesn't have the reliability due to not being able to handle the horsepower of a Rotax 670. I appreciate any input you guys can share.

  4. Posted

    I was wondering if you guys are running with the RK400C clutch in your C Drive reductions?  I have a 670, with a 3.0 ratio in the C Drive and  it's been years since I ran it due to health reasons but now I'm trying to finish the project that I started. I found that on start up, the 670 shakes pretty hard, swinging that 72 inch Warp drive prop but smoothens out by me adding primer and some throttle to get it to run/idle smoothly.

    My prop is 10 to 11lbs, which was recommended to me by Warp Drive. I think that shaking is awful hard on the motor, the drive assembly and even feel it in the whole airframe. 

    So aside from asking if you guys run clutch's, what gear ratio, what prop model, size and weight are you guys using?  Do you guys switch to a heavier rubber donut isolator?

     Do you guys suffer with the heavy vibration on start up and shut down like I do? 

    Thanks for any info you can share.