Activity Stream

Activity Stream



  1. Mendlerr added a post in a topic More power than a 582   

    No doubt the prop makes a huge difference, ask me how I know.
     
    I emailed Rotax Rick again just to ask another question, why limit the 670 power to 89 when from the factory it makes 120+.  He had a good answer.  When he emails it doesn't always make sense and I have to ask him for clarification.   Not sure if it's a language barrier or typing really fast but here is what he sent me last night after I posed the question "why limit the power so much".  If it doesn't make alot of sense let me know.
     
    Look at the big picture. The Rotax Ski Doo & the Rotax Sea Doo from the early 1990's through 1999 were about the same engine design. Same intake, cylinders, crankshaft ( intakes rods, main bearings ,rod bearings ( upper & lower) etc ) A 1998 Rotax 670 Ski Doo & a 1998 720 Sea Doo are about the same engine. The Ski Doo 670 made 132 hp The larger Sea Doo made only 85 hp. WHY It was detuned because it could be ran wide open for mile after mile. If you tried that with a Ski Doo you would kill yourself . In other words I can build a 670 that would give you 175 hp for a VERY short time. I can give you a 670 that will make 89 hp for a limited time, Back the 670 down to a cruise of 60 hp and it will last a very long time. Keep in mind a 670 is only 10 lbs more than a 582 but 24 more hp. HOW CAN IT DO THIS, ONLY VERY CAREFULLY. Limit the throttle to what you need, then run it like your 582 , You will get over the trees with ease and cruise at 1 gph less in gas. Not a bad deal. Keep in mind we use far better rods than a stock 582, plus better pistons and we surface  and deck the head & cylinders . All this makes for a better & safer engine , BUT it has it's limit. If I was not protective of my customers I would be selling these at 105 hp .   I am not trying to sell the 670 by any means but it seems like a good option for us guys who cannot afford the 4-strokes and need alot more climb.  Upgrading to the 670 WILL improve the cruise but only if you change your prop to a larger one with more pitch. 
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  2. Mendlerr added a post in a topic Pre-mix techniques   

    I add penzoil 2-stroke air cooled oil to a 5 gallon gas tank, then add the gas.  I do not buy my fuel at the airport, we do not have MOGAS and I cannot afford 100LL so I take it 5 Gallons at a time.  In the Rotax manual it tells you 50:1, Rotax Rick and a few other engine builders recommend 40:1.
     
    I recently removed my oil injection after recording what it was flowing in flight and it was only flowing 70:1 to 100:1 at WOT, the previous owner had the same results so we decided that it would be best to remove it.
     
    Don't let premixed fuel sit for too long, the octane rating plummets when the oil is added and the longer it sits the worse it gets.
     
    A local Rotax 2-stroke repairman who has a 582 powered AirCam (twin engine experimental) swears by Phillips 66 2-stroke oil at 45:1 ratio and 1 ounce of Marvel Mystery Oil for every 5 gallons.  He told me he has had over 1200 hours on his Rotax's using this method with only regular decarbonizing. 
     
    Just shows how different peoples opinions vary
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  3. Emory Bored added a post in a topic Pre-mix techniques   



  4. flattie45 added a post in a topic Where did you fly today?   

    I made a few trips in the last week or so. An older brother had purchased a 9.3mm CZ that he had yet to fire, so we went out the day before Memorial Day to the Knik Glacier/Lake George area to put a few rounds through it. Holy smokes, was that place busy! Just about every strip had at least one airplane on it, and the radio was quite busy. We ended up landing at a strip a little ways upstream from the upper gorge, and fired towards the mountains. Coming back into Merrill Field was crazy, as it was hard to get a word in edgewise with as much traffic as there was. Overall, a beautiful day. I swear that the leaves were noticeably greener on the return trip.
     

     
     
     
    The following Thursday I got up early and headed up the west side of the Susitna valley. I wasn't able to leave as early as I wanted, and settled for a 6:15 departure from Merrill. No clouds at all and just a slight breeze.
     A few miles from the Eightmile airstrip, closer towards the mountains, I spied what looked like an overgrown airstrip. There was an old caved-in cabin on one side. I made an approach, but the strip was too narrow for my wings and a tree was lying across the middle. Oh well. I continued on up to the Skwentna, just buzzing around, and found a place to get out and stretch my legs before heading back home.
     

     
    -Nate
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  5. wypaul added a post in a topic Rigging changes   

    The cheeks are open and the lip is factory, there is an excessive amount of flow at this time through the cowling.
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  6. kl7jw added a post in a topic Floats for Sale   

    Well, I can deliver them to Palmer for expenses!
     
     
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  7. akflyer added a post in a topic Pre-mix techniques   

    That would depend on the oil you are using... The oil I run, its 50:1.  The oil injecton gives you ~ 50:1 at WOT and closer to 70:1 at an idle. 
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  8. EDMO added a post in a topic Wide body modification?   

    Cant you get some welding done to make the rear of the doorframe stick out wider?
    Structurally, that would be a lot stronger. Then just cover it with fabric.
    Check out my Foxy Flapper Fotos in the Kitfox IV section, I think - you can see I used the same size tubing as the original, but it makes it 3 inches wider on each side, and a lot stronger.
    You have to re-bend the rear of the doors to fit.
    You can use aluminum, steel, or wood for the stringers - just brace them with standoffs and hysol.
    ED in MO
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  9. lv2plyguitar added a post in a topic Pre-mix techniques   

    So Leni are you recommending a 50:1 mixture?  That would be 16 ounces per 6 gallons.
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  10. akflyer added a post in a topic AVID Flyer STOL With Floats & Skids   

    you can look around and see what they are going for on Barnstormers etc.  I think you would be hard pressed to get much, if any over 20 on it.
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  11. akflyer added a post in a topic Pre-mix techniques   

    Premix is pretty much a non event.  If you have a flue flow meter etc, you have a pretty damn good idea of how much gas your gonna take to fill it up.  Keep your ratio rite cup in the plane.  When I am premixing for my boat, I go in 12 gallon increments.  I know I gotta dump in a quart for every 12 gallons and I know pretty damn close how much gas I will take for each fill up.  I will dump it in slowly while running the pump nozzle with the other hand.  or you can dump in some oil first, then put the gas in and grab the wing tip and shake the hell out of it a few times. 
     
    The other option is to mix it 5 gallons at a time and then dump the 5 gallon can into the wing.  That is a bit anal if you ask me, but some get a warm fuzzy out of it.
     
    I looked at the V2 and it intrigued me, but I have not heard of enough flying around over here to make me want to run out and buy one.
     

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  12. akflyer added a post in a topic HAPPY BIRTHDAY AKFLYERBOB   

    Right on!  Lokks like a great place to hang some deer from!  Where is the meat pole's   That shed needs to be a bit bigger so we can stuff the planes in there when the winds come up
     
    See you next week Mr! I should be getting into Kenai just in time for Beer 30 on Tuesday.
     

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  13. akflyer added a post in a topic More power than a 582   

    There are a few guys that have put the Hirth engines in KF / Avids, but I have damn sure not heard any raving about them other than from the dealer about them being the greatest thing since sliced bread.
     
    When looking at older 912 engines, MAKE DARN GOOD AND SURE you look at the service records as there are a ton of "service" bulletins on them, some mandantory, some not, that could make your "awesome deal" on a 912 or a 912 powered plane turn into a money pit REAL quick.  Some are cheap and easy, others are thousands of bucks to comply... Of course, as an experimental, you dont have to comply, but how much of a warm and fuzzy do you get to have when your flying over hostile terrain knowing that you engine probably (or could have) a KNOWN issue.
     
    I am not knocking the 912 (settle down Larry   ) just making you aware of some potential issues that you could be faced with.  If I could go out and buy a 912 today I would be bolting one on... But if I am gonna spend that kind of money, I will just rebuild my Pacer right now..
     

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  14. lv2plyguitar added a topic in Avidfoxflyers General Hangar   

    AVID Flyer STOL With Floats & Skids
    Just for my information, what do you think my plane is worth.  I have a 1988 kit completed in 2013.  Certificate of airworthiness, original fiberglass and gelcoat floats, skis, wide gear with 21" tires, Garmin 296, mgl avionics instruments. Also have the original factory cargo pod.  It has the HH struts and mark IV cowl.  Rotax 582 with 58 total hours.  The plane and motor have a total time of 58 hrs.
     
    Thanks for your input.
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  15. Emory Bored added a topic in Avidfoxflyers General Hangar   

    Pre-mix techniques
    Here's a question I know Joey could answer but he's out of country right now so I don't know how often he can get to the forum.  Perhaps there are others that have eschewed the injector and gone to the much safer pre-mix plan. 
     
    I suppose I should say up front that I maybe should be kicked off the forum because I went and bought an unfinished Z plane 701.  I just think the folks here are going to be much smarter about 2 stroke operation than anyone else. 
     
    Here's the deal:  I'm thinking of the Simonini Victor 2 Plus for my kit.  It requires pre-mix;  there is no oil injection system.  I figure I can get a couple of gas totes to make my pre-mix while home with no problem but how do you mix when you are away?  Is it safe to pour a quart in the tank and then add gas or do you add gas then pour in the oil?  Do you run the risk of having pure gas get into the fuel lines where it can't be properly lubricated doing it that way?  Am I over analyzing this?  
     
    Rotax Rick also recommends pre-mix for his 670 model so I suspect there might be good reason to do it.  
     
    Anyone with experience here would be welcomed to comment.  
     
    Dan
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  16. akflyerbob added a post in a topic HAPPY BIRTHDAY AKFLYERBOB   

    Thanks guys
    Leni..Don't know about weather here. Have been on Kodiak isle building  on shed.

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  17. 1avidflyer added a post in a topic More power than a 582   

    There are 2 Kitfox 4s on ebay right now with 912 engines for sale. Jim Chuk
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  18. High Country added a topic in Technical tasks   

    Wide body modification?
    So I'm planning to have my 2nd wing complete through the brush coats of eko fill by this weekend and  ready for spray coats so I'm preparing to get back to work on the fuselage. I've decided to remove the stringers and redo it with the wide body modification. My question is what type of tubing should I use for the stringers? I'm thinking 1/2" aluminum, but how thick and does it matter what type of aluminum I use? what would be best? Not sure what the KF's have. next I was thinking about just putting a small piece of tubing to hold the stringer off the front of the airframe aprox 2" then just blend it back in to the airframe with tubing rather than bending sheet metal like most of the modifications are done. I'm not sure that I can bend matching pieces of sheet metal with my equipment and I would hate to have one side be different from the other. what are you guys' thoughts on this? anyone know how much it costs to just have the pieces made, I think Murel Williams does it. may need to give him a call. has anyone here done this modification before... pics just want to have all my ducks in a row so it will be done right. also I was thinking about using Hysol for this modification rather than welding partly due to using aluminum on steel of course.
     
    -Robert-
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  19. akflyer added a post in a topic HAPPY BIRTHDAY AKFLYERBOB   

    Happy Birthday Bob!  I hope you got to go flying for a bit, but I heard the weather has been kinds crappy the last few days..
     
    :bday:
     

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  20. herman pahls added a post in a topic More power than a 582   

    I started this thread since I convinced myself that I need more take-off power than my 582 with a 2.62 gearbox and IFA IVO prop offer for my model 2.
    IVO said a 3.47 gearbox with their 3 blade medium prop would make a big difference in take-off and climb.
    I called a Rotax repair shop here in Oregon to see if they knew of any used 912's for sale not realizing they were also a Hirth dealer.
    Are Hirth engines the latest and greatest that I have somehow not been exposed to?
    I still want a 912 but it makes little financial sense to repower this Kitfox, versus finding a Model 4 with a 912S already installed.
    Any advice?
    Thanks Herman
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  21. Av8r3400 added a post in a topic More power than a 582   

    I don't know.  I was told a seized rave valve caused the last engine out that it had.
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  22. EDMO added a topic in Close Call's and dumb stunts   

    HAPPY BIRTHDAY AKFLYERBOB
    Welcome to the "Middle-aged Club"
    Being young is easy - You got to be tough to get old.  I promise not to remind you next year! 
    EDMO
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  23. BryceKat added a post in a topic More power than a 582   

    Tinkering on the 670s was the constant changing of plugs, carb adjusting, seized RAV valves, chasing the peaky unpredictable power, and on and on.

    What caused the Raves to seize? Thanks, Bryce
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  24. lv2plyguitar added a topic in Avidfoxflyers General Hangar   

    AVID Flyer With 582 and Floats
    I have the original AVID gel coat floats that are under 200 lbs.  I am wondering with the 582 what kind of performance I can expect.  Can you haul two people with floats?  What is the general take off distance with no head wind.  What can I expect the cruise speed to be.  The dry weight of my plane is 568.  It has the 29' 10" STOL wing. 
     
    Thanks
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  25. akflyer added a post in a topic my new power plant   

    it is coming back to life.  I have a good line on a machinist here on the forum who is willing to make the adapter plate to bolt the engine to the gear box.  I have the drawings made and the material cut to rough shape and ready for machining when I get home... I am certain it will take some growing pains and its a good thing I have several stock exhaust systems to play with and butcher to make the exhaust fit inside the cowling yet still retain the stock power, smoothness and lack of head ache / peakiness.  It will not be an over night install, but I am moving forwards with it!  If it pans out, my only issue (ok others issues) is that Suzuki is no longer making the engines for Arctic Cat.  I hope that when they start building them inhouse this year, they dont screw them up and turn a perfect engine into a POS... the good news is you can buy an older (06-09) engine and rebuild it pretty cheaply with new parts.
     

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