Yamma-Fox

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Everything posted by Yamma-Fox

  1. Yamma-Fox added a post in a topic Sea Foam in wing tanks OK?   

    I like Sea Foam for winterizing other toys and stuff and as a lazy ass carb cleaner.   Works good for that, but I'm pretty anal about the plane and do a full teardown and cleaning on that.
    Was thinking SF or MMO more as a  valve cleaner because the previous snowmo owner had a little carbon buildup in there.  Not bad though, probably from running a bit rich, so I think I'll try the old "run the hell out of it" technique first and see if I can blow it out.
    Thanks Chris for your post and research on the topic.
    Sure want to avoid leaky tanks!!
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  2. Yamma-Fox added a topic in Avidfoxflyers General Hangar   

    Sea Foam in wing tanks OK?
    So I am told my tanks will leak if I run ethanol fuel in the wing tanks, but would it be OK to add Sea Foam?
    I'd like to run a high dose through during test running of the Yamaha... to clean the entire system out good, top cyl, valves, ect.
    Opinions ?
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  3. Yamma-Fox added a post in a topic Kitfox 1 for sale   

    10 years ago when I bought my Kitfox 2, it was a "barn find".  I thought I was doing well buying it at $10,300.
    But, as in most project planes and those that have been sitting in the barn, there were "plenty too many" little issues that needed attention!
    So to anyone out there who is shopping like I was back then... for a plane like this, all I can say is:
    I wish I would have waited and bought a fully gone through "turn key and fly me" plane like this from an expert like Jim!!
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  4. Yamma-Fox added a post in a topic Well I'm back..... Video shows importance of pre flights   

    Yep, and Steve I'm thinking about possible high EGT's here as well (skirt scuff/sieze and or piston dome melting), and not so much the coolant temps.
    You would likely see that damage through the exhaust port while cycling the piston past the port.  Guess that'd be something I'd check.
    Hopefully there is no problem but like Jim says it'd be something you would want to know about if it were.
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  5. Yamma-Fox added a post in a topic Well I'm back..... Video shows importance of pre flights   

    Hey Chop,  thanks for coming back man.
    Just a thought here, if it was running lean enough to underperform that much it must have got kind of hot don't you think?
    I'm not sure what I would do about that but maybe someone else here would have an idea what to check over before you put it back in the air.
    I bring it up because I've seen sleds meltdown when the engine side carb boot has a cracks in it, and this scenario is kind of like that.
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  6. Yamma-Fox added a post in a topic WTB - Rotax C gearbox   

    Tough to find new.  Let me know if you locate an outlet.
    Last I heard Rotax discontinued them (still making E boxes though)
    And BTW I think cowlove had a 2.62 listed here for sale a few days ago.
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  7. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Update on teals progress here.  He incorporated an "in gear" sprag clutch prototype that looks really good:
    Simple and space efficient, big huge diameter used in high power applications, well lubed in the oil bath of the gearbox, easily available at auto parts stores, inexpensive to inspect/replace.
    A good HD sprag will really save some wear and tear on the gearbox and engine gear reduction components and also make starts much smoother.
    Nicely done Teal!

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  8. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Oh and I forgot another reason to have the sprag, especially with big (high MMOI) props.  The Yamaha shuts down really fast and abrupt, with virtually none of the "coast down" that a 2 stroke has.
    So without the sprag, when you shut down, the prop momentum is forced to stop abruptly as well, which also causes some shake and stresses with each fluctuation of deceleration from compression pulses.
    With the sprag the motor shuts down how it likes and the prop just overrides and spins down like a free turbine turboprop.
    Maybe teal can post up his vid of test run and shutdown with the sprag.
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  9. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Yeah it should work like my old NSI soob with a sprag..  in the descent like your example, anytime you pull power fast, and also during shutdown the prop will override and "freewheel".  That freewheel  (sprag override) will also happen for very short moments between engine pulses when starting and idling.
    So a downside, like with a centrifugal clutch, is in an engine failure scenario where you cannot get the prop to stop windmilling / freewheeling. 
    Also you need to tie down the prop on the ramp / trailer to keep the prop from spinning and the sprag from running dry  (since in those scenarios there is no oil being splashed up from gears spinning).
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  10. Yamma-Fox added a post in a topic Yamaha Apex Skytrax Adapters   

    Mostly smoother start transitions, not easier.
    The starter is strong enough to spin up the prop.  The clutch allows the prop to override the motor momentarily as it fires off from starter speed and accels up to idle speed, helping keep the engine from getting into the sub-idle "shakes" where the prop and motor can get into a wrestling match.
    Sounds like that helps especially with the bigger props used on this motor.
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  11. Yamma-Fox added a post in a topic What difference does pitch make?   

    Plane hitting vne at the same time engine hits max hp/rev limit..... that sounds like an ideal performance setting to me!
    Maybe do 17.5 if you are going for a long cruise.
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  12. Yamma-Fox added a post in a topic Polishing scratches out of windshield   

    Holy crap Ed!    Your like a plexiglass polishing Ninja!!!
    Man, you're hired!   I'm sending ya all my plexi off my plane....    and a couple snowmo helmet face shields too!!

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  13. Yamma-Fox added a post in a topic HOw to bend the gear   

    We all have had our ass handed to us out there buddy...  Hell I, as a new TW student, ground looped twice in one day!  (No better way to learn than THAT!!)
    Thanks for posting.  This is a great reminder for everybody to review and think through.
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  14. Yamma-Fox added a post in a topic Polishing scratches out of windshield   

    I was eyeing the kits at ACS.  The description sure sounds good....
    Anyone tried this?
    http://m.aircraftspruce.com/catalog/cspages/scratchoff_1.php?clickkey=9511
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  15. Yamma-Fox added a post in a topic What difference does pitch make?   

    Chart above is from CPS for the 912uls.
    Pretty flat curve!   Looks like adding 400 static rpm would only add about 5 HP.
    But enough paper speculation!!
    Fly it and time a few runs from brake release to say 500 or 1000 agl.  Then pitch for 5300 and see what the difference is in time to climb and also see if you notice better off the ground performance.
    In my O300 Maule (yeah I know, apples and oranges, but) I made a 300 rpm pitch increase and it was VERY noticeable!
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  16. Yamma-Fox added a post in a topic What difference does pitch make?   

    The power curve of that motor would show if you would get better TO perf with more static rpm.  Likely the engine will produce more HP (and thrust) at a higher static rpm.  Problem obviously is the revs might be higher  than you want in cruise when you set for optimal power during TO.
    My plan is to do some static thrust pulls at different pitch settings and get an idea of where my prop-engine combo will work best (also considering that rpm "ram" rise during the TO roll and in cruise)
    With a fixed pitch prop it obviously will end up being a comprise to a cetain degree
     
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  17. Yamma-Fox added a post in a topic NSI Subaru E-81 (118 HP) for sale   

    Nope... couple people sniffing around but I still got it.
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  18. Yamma-Fox added a post in a topic Converting airstream trailer into hauler   

    Those wheel wells gonna be a problem?
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  19. Yamma-Fox added a topic in For Sale and wanted, you got it, I want it   

    Rotax 670 - 2 hrs TT
    Dunno anything about this one, just a repost from a Yamaha Facebook group member trying to sell.
    You'll need to look his name up in FB to find him if you are interested.
     

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  20. Yamma-Fox added a post in a topic Converting airstream trailer into hauler   

    Cool idea!
    I wouldn't have thought you could fit a seaplane in something like that.
    Post up some pics when you get it all done.  I'd like to see how that works out.
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  21. Yamma-Fox added a post in a topic Yamaha RX1 Engines   

    Easiest way is the "water trick".  Essentially you fill the clutch bolt hole with water, then find another bolt that has threads that match the larger threads in the center of the clutch (get a flashlight and you'll see them), wrap teflon tape on those threads, and thread it in....  the hydro pressure forces off clutch.
    Here is a vid of one way to do it using a bolt from the sled.  I would weld the hole on the end of the bolt closed if I used that bolt, wrap teflon, tip engine up, fill water, thread bolt in, pressurize water... off comes clutch.
    (And no that's not me in the video...  I'm a hell of a lot uglier than that)   
     
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  22. Yamma-Fox added a post in a topic Hirth EFI unit on a Rotax 582?   

    Wonder if that is a mechanical fuel injection?   Kinda like my subaru which it is basically like a garden hose sprayer nozzle:  as you push the throttle body plate open it also opens the fuel sprayer nozzle.
    That as opposed to a digital efi where it controls injectors via a computer,  automatically adjusting for engine temp, air temp, and pressure alt, ect.
    The mechanical FI doesn't seem like too much of an advantage over carbs... except that you can incorporate a lean/rich mixture lever in there where it offsets the fuel nozzle position with respect to the throttle body as they move together.
    I really dont know much about it.  Hopefully someone here who has tried it might chime in.  But seems like tuning for all the carb ranges might be difficult (rich at a certain rpm, lean at another..)  maybe more workable on a 4 stroke where a little lean here or there isn't as big of a deal.
     
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  23. Yamma-Fox added a post in a topic NSI Subaru E-81 (118 HP) for sale   

    Top posting here....  still available.
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  24. Yamma-Fox added a post in a topic Hello from central Minnesota   

    Dang, no not able to make it to Anoka...  but hopefully you can swing up north sometime and put another set of eyes on my work!
    Also, Matt Plante (Yam FB group) over in Stacy is halfway done with his Wild West Highlander.  His FWF Apex is coming from Steve sometime later this year.
    So if you're looking to see how to do a Yamaha the right way, that'd be the one to look at! 
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