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582 clutch or not?

19 posts in this topic

Posted

So I have been thinking about getting a RK400 clutch for my 582 for a while now and have been on the fence. I'm wanting to hear from those that have flown both with and without a clutch. I've read all I can find and see the following pros and cons to using a clutch

Pros

  • Easier starting
  • Smoother idling
  • Probably less stress on the gears, crank, rods, etc.
  • Warm up without prop spinning
  • Less float on landing
  • Steeper approach (could be a con too depending)
  • Great for float flying (I'd guess for ski flying too)

Cons

  • Reduced glide performance
  • Extra maintenance item
  • Can't rotate engine with the prop (ie: for maintenance)
  • About 4 extra pounds weight up front from what I have read

Questions:

  • How often do the clutch linings need to be replaced.
  • Would you describe the glide penalty as "worth it" for the other benefits?
  • If you have experience with the clutch would you go back to operating without one?

Right now my engine idles rough below about 2500 rpm when warm and even a bit higher when cold. I am a snowmobiler and am used to starting the sleds and letting them warm up good and listening to sewing machine smooth idle as the sit there warming up. I see some benefit to having really smooth idle without the prop turning during warm up especially during the cold months. Now that it is getting colder outside I'm leaning more and more toward getting a clutch for some of these reasons. What do you experienced clutch users say? 

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Posted

Never have used the clutch, so can't comment on that, but if you still have the factory # 55 idle jet , you may get a smoother and maybe slower idle if you switch to a 50 or 45.  The 55 is pretty rich.  JImChuk

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Posted (edited)

I went with a 670 on the mod 4 with a  clutch I used with the 582 and it pealed one shoe lining.

I bought a new clutch and installed on the 670 and after only 3 hrs it started slipping and as

you would expect the first indication was heat and blueing color, removed.

I don't believe the lining can be replaced. Maybe if it was sent back they maybe could do it????

I worked great on the 582, wheels and skis.

Edited by akflyerbob

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Posted (edited)

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.

Edited by Yamma-Fox
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Posted

Oh and also I found it interesting to hear when I talked to Steve Henry about the windmilling prop. He said he couldn't tell much of a difference in his glide ratio between a windmilling prop or a "stopped " prop. 

If it were anyone but the "Dead stick take off" guy telling me that I would have expressed a doubt about that opinion but I figured he was pretty well qualified to it. ;)

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Posted

I doubt there is a lot of difference between windmilling and stopped on a fixed pitch prop.  The difference comes in when a constant speed is windmilling versus when it is feathered, that makes a big difference!

Mark

 

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Posted

That all sounds good. For those that run them how is the reliability of the RK400 on a stock 582? Sounds like on more powerful engines they may be iffy. 

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Posted

I know you are looking for how it does on a 582 and there are some experts here on that.  But FWIW Ive got two friends with 140 HP Yamahas running the clutch and the 79" prop.  Both have over 500 hours on them and the clutches have been doing fine for them.   Apples and oranges for sure but I only bring it up because I think that says something about capacity and longevity.

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Posted

I know you are looking for how it does on a 582 and there are some experts here on that.  But FWIW Ive got two friends with 140 HP Yamahas running the clutch and the 79" prop.  Both have over 500 hours on them and the clutches have been doing fine for them.   Apples and oranges for sure but I only bring it up because I think that says something about capacity and longevity.

No. That is excellent information. I just found out I might have an opportunity to get a 912 for a really good deal so I'm going to see if that pans out, but if not I think I will get the clutch for the 582.

 

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Posted


I am currently running two Avids. One with and one without. All your Pros and Cons are spot on. I have not had to touch my mine maintenance wise in 47 hours so far. One con I've found is that if you have a long taxi ( I do from my hangar) you have to taxi really fast or be constantly in and out of the power as a normal taxi speed puts you right at an RPM where you are slipping the clutch. The windmilling thing is not really an issue. It's actually pretty hard to get it to fully disengage unless you slow way down and do a long descent. Under a normal traffic pattern ops you don't even notice it. Idling at 900 rpm while you do your preflight in the cold is damn nice though and those start ups in the cold are wayyyy easier. Just look at the key and it's idling. I've had issues with my 70" warp and 2.62 box on my other one cold starting even with an Odyssey PC585. The ducatti needs 300 rpm at the crank to produce a spark. 299 and it will NOT fire when it's cold and your plugs have oil on them.

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Posted (edited)

I have had engine outs with the clutch and a free wheeling prop.  I have had engine outs without the clutch and a stopped prop.  I will take the later any day of the week.  If one does not think a freewheeling prop makes a difference on glide then one should spend some time flying electric RC gliders with and without the engine brake and see the flight time differences in a freewheeling prop versus a stopped prop.

These are high drag airplanes to begin with.  They glide like an anvil.  With the prop freewheeling they glide like a greased anvil.

Edited by akflyer
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Posted (edited)

Now that I have a new battery and can actually start my engine, I'm back to deciding whether or not to get a clutch. The only thing stopping me at this point is the fact that you cannot turn the engine by turning the prop.  On sleds and this 582 I have always done piston checks for various reasons by looking in the ports while rolling the engine around. With no engagement to the prop and no pull start, I don't see a easy way to accomplish it. Seems to me that one would have to pull the gearbox to rotate the engine. So, for you guys with clutches, how are you handling things like checking the pistons when looking through exhaust ports? 

Oh and that possible deal on the 912 fell through.

Edited by 109jb

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Posted

Now that I have a new battery and can actually start my engine, I'm back to deciding whether or not to get a clutch. The only thing stopping me at this point is the fact that you cannot turn the engine by turning the prop.  On sleds and this 582 I have always done piston checks for various reasons by looking in the ports while rolling the engine around. With no engagement to the prop and no pull start, I don't see a easy way to accomplish it. Seems to me that one would have to pull the gearbox to rotate the engine. So, for you guys with clutches, how are you handling things like checking the pistons when looking through exhaust ports? 

Oh and that possible deal on the 912 fell through.

With the spark plugs out you might be able to turn the engine over with a wooden dowel through a spark plug hole. 

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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.

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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. 

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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.

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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.

 

 

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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?

 

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Posted

Yep and he was talking about the c box and his tmr clutch.

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