Mark IV For Sale

117 posts in this topic

Posted

You know your stuff Ed. I do have a Reductions 1.84:1 ea81. I have another engine that I am planning on building up. That way the plane keeps flying while I get this other one built.post-232-13634034669603_thumb.jpg

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Posted (edited)

You know your stuff Ed. I do have a Reductions 1.84:1 ea81. I have another engine that I am planning on building up. That way the plane keeps flying while I get this other one built.post-232-13634034669603_thumb.jpg

I have heard that the EA-81 can also be bored oversize and VW (?) pistons used. But not sure on that.

Mine is also 1.84 reduction, by Dave Johnson of Canada - he is dead now.

Stratus will exchange a reground cam and lifters for yours - used to be $125 plus shipping.

Ed in MO

Edited by Ed In Missouri

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Posted

Couple of posts back mention 300' per minute climb with 2 guys in the Sube. powered plane. My flying partner and I were practiceing landings again yesterday with our 582 powered Avid MK IV. Between the two of us, that's probably 420 lbs, (I'm the light one) and I had about 15 gallons of fuel at least. It was about 35 F and we were on skis. We were getting about 700' per minute climb. Empty weight on the plane is 585 lb. Take care, Jim Chuk

I have heard that the EA-81 can also be bored oversize and VW (?) pistons used. But not sure on that.

Mine is also 1.84 reduction, by Dave Johnson of Canada - he is dead now.

Stratus will exchange a reground cam and lifters for yours - used to be $125 plus shipping.

Ed in MO

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Posted (edited)

Couple of posts back mention 300' per minute climb with 2 guys in the Sube. powered plane. My flying partner and I were practiceing landings again yesterday with our 582 powered Avid MK IV. Between the two of us, that's probably 420 lbs, (I'm the light one) and I had about 15 gallons of fuel at least. It was about 35 F and we were on skis. We were getting about 700' per minute climb. Empty weight on the plane is 585 lb. Take care, Jim Chuk

Jim,

He also said he had his 68 inch prop at 7 degrees - thinking he has it too flat - donno what rpm he is pulling, but sounds like he needs to grab more air to climb? Thats a lot less pitch and prop I was told to use, but maybe he has less hp than mine?

Note that Leni said that Randy's Soob would outclimb his 582.

Ed

Edited by Ed In Missouri

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Posted (edited)

Gentlemen. I started at 8.5 degrees but could only pull 4200 rpm static. I took this up to 4425 (needle tach) with 7 degrees static. Going to turn it back to 8.5 to see if it does grab more air and actually get up and go. Too flat with the pitch versus the torque range of the engine with a stock cam is what I'm thinking. By the way I'm no expert. Ben

Just did a little math and the numbers do seem to jive. 582 total weight is 585empty +420crew+90fuel=1095 for 700 fpm.(2 passengers). EA81 total weight is 712empty weight+200me+90fuel=1002 for 800fpm@65. I have the avid wide gear, heavy duty truss, big skis and heavy duty custom tail spring.(home made). I better get with it and up my horsepower. Still waiting for that elusive 912 who must be viewing this to put it on record. B

Edited by IFMT

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Posted

Gentlemen. I started at 8.5 degrees but could only pull 4200 rpm static. I took this up to 4425 (needle tach) with 7 degrees static. Going to turn it back to 8.5 to see if it does grab more air and actually get up and go. Too flat with the pitch versus the torque range of the engine with a stock cam is what I'm thinking. By the way I'm no expert. Ben

Just did a little math and the numbers do seem to jive. 582 total weight is 585empty +420crew+90fuel=1095 for 700 fpm.(2 passengers). EA81 total weight is 712empty weight+200me+90fuel=1002 for 800fpm@65. I have the avid wide gear, heavy duty truss, big skis and heavy duty custom tail spring.(home made). I better get with it and up my horsepower. Still waiting for that elusive 912 who must be viewing this to put it on record. B

I would sure like to have the formula for fpm - probably got it somewhere, but easier to ask, and memory fading fast!

ED in MO

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Posted

I'm still curious what a mark IV with the 912 empty weight is. Is it 50 lbs lighter than a sube? is it 100 lbs lighter? And how does this translate into performance? Anybody out there reading this actually flying one? Cheers gents.Ben

My MKIV with the 912A weighs 616 empty. I only have 1/2 hr on it so far so no number to report at this time.

Paul

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Posted

Looking forward to your performance results. 912 comes in almost 100 pounds lighter. Is your engine the 80 horse version?

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Posted

Gentlemen. I started at 8.5 degrees but could only pull 4200 rpm static. I took this up to 4425 (needle tach) with 7 degrees static. Going to turn it back to 8.5 to see if it does grab more air and actually get up and go. Too flat with the pitch versus the torque range of the engine with a stock cam is what I'm thinking. By the way I'm no expert. Ben

Just did a little math and the numbers do seem to jive. 582 total weight is 585empty +420crew+90fuel=1095 for 700 fpm.(2 passengers). EA81 total weight is 712empty weight+200me+90fuel=1002 for 800fpm@65. I have the avid wide gear, heavy duty truss, big skis and heavy duty custom tail spring.(home made). I better get with it and up my horsepower. Still waiting for that elusive 912 who must be viewing this to put it on record. B

Ben,

I can't give you a comparison between the stock EA81 and the 100 hp Stratus since I have only flown the Stratus in my plane. There are other factors involved as well such as the Stratus redrive ratio being 2.2:1 with my 72" IVO vs. your 1.84:1 and 68" Warp Drive, but I think the additional HP from the milled heads, reground cam and possibly the carb/manifold set up may be pretty significant. My Avid+ is much heavier than any of the MKIV's mentioned in this post so 1150 to 1200 lb's is pretty common loading for me. With the IVO flattened out I get about 4800 rpm and about 800 fpm at that weight. At 1500 lb the climb is more around the 300-400 fpm range. With the advantage of the IVO IFA prop, cruise is somewhat dependent on how much fuel you want to burn. I typically cruise at 3600 to 3800 rpm and lean to 1450 degrees on the EGT's. 70 mph is under 3 gph, 80 mph is under 4 gph and 90+ mph is about 4.5 gph. I usually am flying at under 2000 ft AGL but I have found when I am up at 4000 I can can lean to about 4.1 gph at 90+ mph. I don't know how much of that info may be useful to you in deciding if you want to have your heads and cam reworked.

Randy

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Posted

Looking forward to your performance results. 912 comes in almost 100 pounds lighter. Is your engine the 80 horse version?

Yes, 80 HP 912. We will start having calmer day here before long and I can get back to the phase 1 flight tests.

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Posted (edited)

Ben,

I can't give you a comparison between the stock EA81 and the 100 hp Stratus since I have only flown the Stratus in my plane. There are other factors involved as well such as the Stratus redrive ratio being 2.2:1 with my 72" IVO vs. your 1.84:1 and 68" Warp Drive, but I think the additional HP from the milled heads, reground cam and possibly the carb/manifold set up may be pretty significant. My Avid+ is much heavier than any of the MKIV's mentioned in this post so 1150 to 1200 lb's is pretty common loading for me. With the IVO flattened out I get about 4800 rpm and about 800 fpm at that weight. At 1500 lb the climb is more around the 300-400 fpm range. With the advantage of the IVO IFA prop, cruise is somewhat dependent on how much fuel you want to burn. I typically cruise at 3600 to 3800 rpm and lean to 1450 degrees on the EGT's. 70 mph is under 3 gph, 80 mph is under 4 gph and 90+ mph is about 4.5 gph. I usually am flying at under 2000 ft AGL but I have found when I am up at 4000 I can can lean to about 4.1 gph at 90+ mph. I don't know how much of that info may be useful to you in deciding if you want to have your heads and cam reworked.

Randy

Ben, that 20 to (35 advertised) extra hp will surely make a big difference for you - However, you will probably need longer blades on your prop - The shortened blades are not good for climbing either - I am wondering if you may have a slightly "sick" engine - have you checked the compression, timing, Valves, etc?

The Stratus is about as good as it gets with the 81 - Just $7000 more than I wanted to spend at the time I bought mine.

I really dont think the twin carbs are any better than the Holley or Carter 2 brl.

EFI might be better than either, but costs $.

ED in MO

Edited by Ed In Missouri

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Posted (edited)

I know that my ea81 is mechanically on spec. It was a total rebuild, everything new, done by a 'professional' while the previous owner still had it. It runs perfect.I will compression test it though just to know. Burns no oil and fires up like it should. Haven't checked the timing but I see that the distributer is turned as far as it can go for the advance. Warp drive actually recommended cutting the prop down because of the 1.84 reduction. He also said that the 68 inch would still be lots of prop if I up the horsepower later. Apparently there are many smaller props running with a lot more power on gyros. It does have an air filter(foam) and carb heat box system. I do notice that the engine doesn't slow down with carb heat applied like you see on aviation engines(0-320). I'm thinking that is because of the hot water running through the intake. I'm going to take the filter out and see if that lets it breath better. Meanwhile I'll start disassemble on the other one to get the cam sent away. Thanks. Ben

Edited by IFMT

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Posted

I know that my ea81 is mechanically on spec. It was a total rebuild, everything new, done by a 'professional' while the previous owner still had it. It runs perfect.I will compression test it though just to know. Burns no oil and fires up like it should. Haven't checked the timing but I see that the distributer is turned as far as it can go for the advance. Warp drive actually recommended cutting the prop down because of the 1.84 reduction. He also said that the 68 inch would still be lots of prop if I up the horsepower later. Apparently there are many smaller props running with a lot more power on gyros. It does have an air filter(foam) and carb heat box system. I do notice that the engine doesn't slow down with carb heat applied like you see on aviation engines(0-320). I'm thinking that is because of the hot water running through the intake. I'm going to take the filter out and see if that lets it breath better. Meanwhile I'll start disassemble on the other one to get the cam sent away. Thanks. Ben

Ben,

Where are you at in the Yukon? I am thinking about trying to put a fly in together this summer for the Avid / Kitfox folks.

:BC:

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Posted (edited)

I'm right at Whitehorse. I generally fly off of 2800 foot strip on the west side of Whitehorse called "cousin's airstrip". There are a few ultralights around but I only know of one Avid magnum that a buddy has. A few chinooks and challengers. Couple of kitfoxes but I don't think they are getting any use. Lots of cubs, aeroncas, cessnas etc. around here. There was a flyin down at carcross today but -26 celc. is down right cold in my plane so I didn't go. Much below -15 and the heat just doesn't keep up. I'll go on google earth and check out the route. I think for the most part people follow the Alaska highway over here. Cheers.

Edited by IFMT

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Posted (edited)

I'm right at Whitehorse. I generally fly off of 2800 foot strip on the west side of Whitehorse called "cousin's airstrip". There are a few ultralights around but I only know of one Avid magnum that a buddy has. A few chinooks and challengers. Couple of kitfoxes but I don't think they are getting any use. Lots of cubs, aeroncas, cessnas etc. around here. There was a flyin down at carcross today but -26 celc. is down right cold in my plane so I didn't go. Much below -15 and the heat just doesn't keep up. I'll go on google earth and check out the route. I think for the most part people follow the Alaska highway over here. Cheers.

Ben,

I hope you will be able to give us a comparrison report when you get the new engine installed.

It would be nice if you guys could get together at Tok, or Northway, so the Alaskans dont have to leave their pistols home.

And FAST EDDIE"S is at Tok for good food.

Ed in MO

Edited by Ed In Missouri

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Posted (edited)

A new Avid Mark IV popped up locally for under $10,000. He told me he just recovered the aircraft but he did it over a possibly rusty fuesalage. So I guess the fabric that he just put on needs to be cut off and the fuesalage rebuilt? Could someone tell me why anyone would do this?

Apparently its got a Rotax 582, new prop and new fabric. He didn't give me any other info on the phone other then he needs the money.

Edited by RMendler

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Posted

If it's close by, I would go look at it to try to better see what he's talking about. Maybe it's not as bad as it sounds. Big difference between specks of rust starting to show that were sanded off and repainted before the recover, and rusted tubes that you could stick a sharp punch through. I did the first one when I recovered my MK IV, but would never cover the second situation. If it was totally rusted and the guy just recovered it to pick up a quick buck, he wouldn't tell you about it I think. If nothing else, you will get to see another airplane and if you look hard at it, you always learn from that. Take care, Jim Chuk

A new Avid Mark IV popped up locally for under $10,000. He told me he just recovered the aircraft but he did it over a possibly rusty fuesalage. So I guess the fabric that he just put on needs to be cut off and the fuesalage rebuilt? Could someone tell me why anyone would do this?

Apparently its got a Rotax 582, new prop and new fabric. He didn't give me any other info on the phone other then he needs the money.

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Posted

The fuse should have been powder coated. If it was truly rusted up too bad then there had to be some major damage done to it prior to the recover. I am with Jim, go take a look at it and see just how bad it is. A few speckles are not something worth loosing too much sleep over.

:BC:

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Posted

Not so sure all Mk-IV's were powder coated. My old Mk-IV, s/n 1127D, was epoxy primed not powder coated.

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Posted

i may go look, its only 2 hours away.

he also says the previous owner supplied no logs for anything, in fact he said there is zero paperwork available with the sale.

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Posted

Zero paperwork = walk away. Don't waste your time unless you want it as a parts bird.

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Posted

Once again, depends what he means by no paperwork. If the build logs are'nt there and things like that, it wouldn't stop me. I didn't get that with the last 4 Avids I bought. As long as the FAA paperwork is in order, go have a look. If you have the N # go run it on the FAA website. It will come up showing a problem if there is a problem that they know about. If it's listed in his name, and they don't say a problem exists, you're probably good to go paperwork wise. You can always find a builder's manual, I have 3 of them within 4 feet of me right now. Ask him if he has the airwothyness certification. That kind of paperwork IS important! Take care, Jim Chuk

Zero paperwork = walk away. Don't waste your time unless you want it as a parts bird.

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Posted

Went and looked at the add for the plane you are talking about. The N# was there so I ran it. Plane is in seller's name, and registration is current till 2016. Grab you car keys! If I lived closer, you might have to race me to it. LOL Jim Chuk

Once again, depends what he means by no paperwork. If the build logs are'nt there and things like that, it wouldn't stop me. I didn't get that with the last 4 Avids I bought. As long as the FAA paperwork is in order, go have a look. If you have the N # go run it on the FAA website. It will come up showing a problem if there is a problem that they know about. If it's listed in his name, and they don't say a problem exists, you're probably good to go paperwork wise. You can always find a builder's manual, I have 3 of them within 4 feet of me right now. Ask him if he has the airwothyness certification. That kind of paperwork IS important! Take care, Jim Chuk

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Posted (edited)

So guys, I know we briefly discussed Rotax 2-strokes. I've done alot of independent research also but I want to hear from the guys who really know the 582 and its innerworkings.

Here's the skinny I'm looking for:

Oil injection systems? Love them? Hate them? Why? Is it easily removed? How do you determine how much oil is actually flowing (40:1, 50:1, 100:1)?

I personally feel that mixing your own gas/oil is better, one less system to fail and less weight. As long as you don't forget

Spark plug changes every 25-50 hours? Best plugs? Gapping?

I've read 25 hours is normal for the spark plug changes.

What should compression be?

Any good fuel additives to keep these things clean? Zmax, Amsoil, Redline?

Anything else to look for? Clean on a regular basis? Oil/Lube?

Are these Bing Altitude Compensating Carbs worth a damn?

I hear they tend to have air leaks, haha

Edited by RMendler

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Posted

So guys, I know we briefly discussed Rotax 2-strokes. I've done alot of independent research also but I want to hear from the guys who really know the 582 and its innerworkings.

Here's the skinny I'm looking for:

OK, My opinions which with $5.00 might get you coffee at Starbucks

Oil injection systems? Love them? Hate them? Why? Is it easily removed? How do you determine how much oil is actually flowing (40:1, 50:1, 100:1)?

Love it. More reliable than the time you forget to add oil and have a seizure. When properly setup it will reduce oil at idle reducing dirty plugs and combustion chambers at teardwown for maintenance.

I personally feel that mixing your own gas/oil is better, one less system to fail and less weight. As long as you don't forget

Spark plug changes every 25-50 hours?

When engine starting is not as good and idle is not as smooth. Depending on gas used, within the time frame you stated. Avgas will cause poor starting and poor idle much sooner than car gas. Best plugs? NGK SOLID TOPS. Make sure you use solid tops! Gapping? Factory Rotax recommended gap. I think around 0.020. Reason so narrow is spark has to jump two gaps.

I've read 25 hours is normal for the spark plug changes.

What should compression be? Never cared or measured. Just ran to 600 hours (2Xtbo), tearing down and inspecting evey 150 or so hours.

Any good fuel additives to keep these things clean? Zmax, Amsoil, Redline? Never used additives.

Anything else to look for? Clean on a regular basis? Oil/Lube? Every 150 or so hours I took my engine apart to check for sticking ring below the dyke ring gap and unstick if stuck, and to clean the combustion chamber and look for scratches on the cylinder walls and piston skirts indicative of seizure. Regularly inspect carb mounting boots and replace at first sign of cracking. If you are using Bing polyurethane fuel line, replace when it turns from blue to green. If it's brown and you have waited too long. There's probably a million other things I am not thinking of.

Are these Bing Altitude Compensating Carbs worth a damn? I do not think the bings used on the two strokes are cnstant depression carbs (somewhat altitude compensating) like are used on the 912. I designed a mixture control for mine.

I hear they tend to have air leaks, haha

They work fine. I've heard that air leak stuff too but all the factory support in terms of jetting is worth its weight in gold compared to the performance increase you might get with another carb, but no jetting support!

ChrisB

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