---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Tue 07/17/07: 22 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:33 AM - Re: FS 1 First Flight questions (Thom Riddle) 2. 06:00 AM - Re: Re: FS 1 First Flight questions (Richard Girard) 3. 06:59 AM - Re: FS 1 First Flight questions (Richard Pike) 4. 07:04 AM - Re: FS 1 First Flight questions (tlongo) 5. 08:13 AM - Re: Re: FS 1 First Flight questions (Richard Pike) 6. 08:39 AM - Two Stroke Prop and Carb Tuning (John Hauck) 7. 08:39 AM - Re: Kolb Mark III fuel tanks (Kirby Dennis Contr MDA/AL) 8. 09:47 AM - Re: Re: Flying characteristics- Kolb Firestar vs. Quicksilver Sprin (Dana Hague) 9. 09:48 AM - Re: Two Stroke Prop and Carb Tuning (Richard Pike) 10. 10:13 AM - Re: FS 1 First Flight questions (Eugene Zimmerman) 11. 10:19 AM - Re: FS 1 First Flight questions (Richard Girard) 12. 10:36 AM - Re: Re: Kolb Mark III fuel tanks (Richard Girard) 13. 11:25 AM - Re: Two Stroke Prop and Carb Tuning (John Hauck) 14. 11:34 AM - Re: Re: Flying characteristics- Kolb Firestar vs. Quicksilver Sprin (John Hauck) 15. 11:36 AM - Re: FS 1 First Flight questions (John Hauck) 16. 01:28 PM - Re: FS 1 First Flight questions (Thom Riddle) 17. 02:58 PM - Mushy control stick (Paul Petty) 18. 03:02 PM - Re: Mushy control stick (Paul Petty) 19. 04:22 PM - Re: Kolb Mark III fuel tanks (JetPilot) 20. 06:23 PM - Re: FS 1 First Flight questions (Eugene Zimmerman) 21. 06:52 PM - Re: FS 1 First Flight questions (John Hauck) 22. 09:48 PM - Re: Mushy control stick (lucien) ________________________________ Message 1 _____________________________________ Time: 04:33:14 AM PST US Subject: Kolb-List: Re: FS 1 First Flight questions From: "Thom Riddle" Erik, I believe that the absence of an explicit EGT range specification for the 447 in the Rotax 2-stroke Operators Manual was an accidental omission, not an indication that this particular engine has no limits. Since all the air-cooled Rotax aircraft engines are built similarly using similar technologies, I am taking the 503 numbers, a close relative of the 447, as proxy for the 447 in regards to normal EGT range. I am getting mid-range EGTs around 1200-1250 and that is too hot for this engine. For what its worth: 1- Mike Stratman of CPS, says that 1200F EGT is too hot. 2- Rotax-service.com says that the normal EGT range for all Rotax aircooled engines is 860-1080F with a max of 1200F. 3- I don't know what the Rotax gurus at Lockwood etc say but I will find out. -------- Thom in Buffalo N197BG FS1/447 do not archive -------------------- "Blind respect for authority is the greatest enemy of truth." Albert Einstein Read this topic online here: http://forums.matronics.com/viewtopic.php?p=124307#124307 ________________________________ Message 2 _____________________________________ Time: 06:00:55 AM PST US From: "Richard Girard" Subject: Re: Kolb-List: Re: FS 1 First Flight questions Thom, I checked the Bing manual for the proper clip position on the needle of the type 54 carb. All versions of the 447 should have the clip set to the #2 position (from the top), unless you have the 447DC without the intake silencer installed, then it goes to #3. It should be noted that the 447DC w/o silencer uses a different needle (6G1) than the other models (15K2). 447 and 447DC with the silencer use the same needle, but a different needle jet. The 447 uses a 2.70 needle jet, the 447DC uses a 2.68. Hope this helps. Rick On 7/17/07, Thom Riddle wrote: > > > Erik, > > I believe that the absence of an explicit EGT range specification for the > 447 in the Rotax 2-stroke Operators Manual was an accidental omission, not > an indication that this particular engine has no limits. Since all the > air-cooled Rotax aircraft engines are built similarly using similar > technologies, I am taking the 503 numbers, a close relative of the 447, as > proxy for the 447 in regards to normal EGT range. I am getting mid-range > EGTs around 1200-1250 and that is too hot for this engine. > > For what its worth: > 1- Mike Stratman of CPS, says that 1200F EGT is too hot. > 2- Rotax-service.com says that the normal EGT range for all Rotax > aircooled engines is 860-1080F with a max of 1200F. > 3- I don't know what the Rotax gurus at Lockwood etc say but I will find > out. > > -------- > Thom in Buffalo > N197BG FS1/447 > do not archive > -------------------- > "Blind respect for authority is the greatest enemy of truth." > Albert Einstein > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=124307#124307 > > -- Rick Girard "Ya'll drop on in" takes on a whole new meaning when you live at the airport. ________________________________ Message 3 _____________________________________ Time: 06:59:55 AM PST US From: "Richard Pike" Subject: Re: Kolb-List: FS 1 First Flight questions Been thinking about this and came up with a theory I'll throw out for appropriate abuse: While it is SOP that a correctly propped engine will give you good EGT's and CHT's while bumping red line in level flight, what would be your results if the prop diameter was slightly excessive for your engine? Here is my thinking (your results may vary): if the diameter is slightly too large, then in order to get the engine to turn it's appropriate max RPM, (say 6500) you would need to dial in slightly less pitch than normal, due to the excess load imposed by the excess diameter. Then when reducing the RPM to cruise, the prop is now somewhat under pitched, and the EGT is going to be abnormally high, and the CHT abnormally low. So relative to your situation, any way you can borrow a 2 blade 60" prop to compare and see what happens? Or even a 62" Warp or Ivo, just in case Powerfin (with it's thicker airfoil) is causing a slightly higher load, and requiring a slightly lower pitch? Richard Pike MKIII N420P (420ldPoops) ----- Original Message ----- From: "Thom Riddle" Sent: Monday, July 16, 2007 1:05 PM Subject: Kolb-List: FS 1 First Flight questions > > I flew the new-to-me FS 1 / 447 this morning and discovered a couple > things that I could use some help with. > 1) CHTs are low and EGTs are high during normal cruise speeds. They were > in the normal range only during full power climb at Vy. > > My conundrum: I believe that by increasing the prop pitch a bit this > should improve both the CHT and EGT readings. However, its current pitch > gives me 6,500 rpm at WOT in level flight, which I've always thought was > just about right. The prop is a 2-blade Powerfin x 62". > > What should I do? > > 2) With cruise power (5800 and higher), the elevator seems to be trimmed > at higher IAS than I want or expect, i.e. it wants to descend with hands > off. At lower power settings it seems to be trimmed at about 50 mph IAS, > which I like. Is this an engine tilt(inclination) problem or something > else? > > I don't recall either of these situations in my old early FS. It was trim > neutral at all speeds and EGTs and CHTs stayed in normal even when > descending at low power. > > Thanks for any guidance. > > -------- > Thom in Buffalo > N197BG FS1/447 > do not archive > -------------------- > "Blind respect for authority is the greatest enemy of truth." > Albert Einstein > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=124110#124110 > > > ________________________________ Message 4 _____________________________________ Time: 07:04:07 AM PST US Subject: Kolb-List: Re: FS 1 First Flight questions From: "tlongo" If EGT is okay at full throttle and too high at cruse that means your main jetting is good and needle too lean. Check the holes in sides of needle jet tube if they have a build up that will cause a lean mixture even if your needle is set in the correct clip setting. You can use a toothpick to clean the holes or a piece of wire then blow out with air. Worth a try, very easy to do. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=124337#124337 ________________________________ Message 5 _____________________________________ Time: 08:13:00 AM PST US From: "Richard Pike" Subject: Re: Kolb-List: Re: FS 1 First Flight questions Not necessarily. See here: http://www.bcchapel.org/pages/0003/pg11.htm Richard Pike MKIII N420P (420ldPoops) ----- Original Message ----- From: "tlongo" Sent: Tuesday, July 17, 2007 10:03 AM Subject: Kolb-List: Re: FS 1 First Flight questions > > If EGT is okay at full throttle and too high at cruse that means your main > jetting is good and needle too lean. ________________________________ Message 6 _____________________________________ Time: 08:39:02 AM PST US From: "John Hauck" Subject: Kolb-List: Two Stroke Prop and Carb Tuning | http://www.bcchapel.org/pages/0003/pg11.htm | Richard Pike Richard P: How do you do a spark plug check? john h mkIII PS: I changed to subject line to be more in line with what is being discussed. ________________________________ Message 7 _____________________________________ Time: 08:39:24 AM PST US Subject: Kolb-List: Re: Kolb Mark III fuel tanks From: "Kirby Dennis Contr MDA/AL" "Bruce Chaisson" asked: << Does anyone know where to buy 8 gal. plastic fuel tanks to replace the standard 5 gal ones? I know Kolb is selling 6 gal replacements but have heard there are some 8 gal ones out there. >> Bruce - I, too, am interested in larger, drop-in replacement fuel tanks for my Mark-III that will not require any cutting of structure to fit. I have heard Quad City Challenger uses 8 (or 10?) gallon polyethylene fuel tanks with the same square 10"x10" footprint that our Kolbs use. But I have not verified this. Might be worth a call ... Dennis Kirby Mark-3, 912ul New Mexico Do not archive ________________________________ Message 8 _____________________________________ Time: 09:47:18 AM PST US From: Dana Hague Subject: Re: Kolb-List: Re: Flying characteristics- Kolb Firestar vs. Quicksilver Sprin At 06:40 AM 7/14/2007, lucien wrote: > >My first UL was a quicksilver MX super, an older design which was the >aerobatic version in the MX series (though I trained in a 2-place sprint). > >But I pretty much agree with the comparisons made by the rest of the guys. >The really significant differences flying-wise are the tailwheel aspect >and the lack of dihedral in the Kolb over the stock sprint. I expect to fly my US pretty soon... with about 10 hours in a Quick (not counting the weightshift Quick I damn near killed myself in) and 400 hours in a Taylorcraft (so the tailwheel doesn't worry me), anything I should bear in mind on my first flight in the US? >...The lack of dihedral though has so many other advantages, though, I'd >recommend removing it even on the quicksilver (which mark smith can help with). Along with a Super (I miss doing aerobatics) that's something I'd like to fly (a Mark Smith Quickalike, I mean)... the Quick I was flying was bone stock, beat up and sloppy, pretty much a pig. -Dana -- -- The only correct outcome to an armed robbery attempt is a dead armed robber. ________________________________ Message 9 _____________________________________ Time: 09:48:03 AM PST US From: "Richard Pike" Subject: Re: Kolb-List: Two Stroke Prop and Carb Tuning How DO I it, or how SHOULD I do it? There's a difference you know... I have always heard that the ideal way to do it is to be running your engine at the RPM & loading you want to check for, leave it there for a couple minutes, and then turn the engine off and then check it. Since there is a difference in prop loading in flight than on the ground, that would mean being right above a suitable strip to chop the engine, glide down, and then pull the plug out and look at it. That should be the ideal to give you an unadulterated reading. Probably running it at the RPM you wanted on the ground would actually work close enough in practice. The way I do it is I leave my plugs in long enough for them to be distinctively colored (at least 15 hours) and then take them out and look at them. (blush, kicks dirt with foot) Which tells me if the engine is running consistently too lean, (whitish-gray) consistently too rich, (black) or more or less right. (brown) And since the stock Rotax specified jetting gives me temps right around 1050-1100, and the plugs are a medium brown, I actually can't remember the last time I did a plug check. Probably the last time I actually did a genuine, hard core, do-it-right-or-else plug check was with a Rotax 277 in the Hummer about 24 years ago. But thanks for asking... Richard Pike MKIII N420P (420ldPoops) PS - this is probably the best description of how to do it- http://dirtbike.off-road.com/dirtbike/article/articleDetail.jsp?id=332655 ----- Original Message ----- From: "John Hauck" Sent: Tuesday, July 17, 2007 11:35 AM Subject: Kolb-List: Two Stroke Prop and Carb Tuning > > > > > Richard P: > > How do you do a spark plug check? > > john h > mkIII > > PS: I changed to subject line to be more in line with what is being > discussed. > > > ________________________________ Message 10 ____________________________________ Time: 10:13:51 AM PST US From: Eugene Zimmerman Subject: Re: Kolb-List: FS 1 First Flight questions Ok Guys, Ill weigh in with my $.02 on this topic. NEVER depend entirely on your EGT gauge to adjust your carburetor. Plug color is a better indication to go by along with using your primer to give an extra small shot of fuel. If the rpms increase with the extra fuel you are obviously lean of peak and should raise the needle to enrich the fuel mixture. If the extra shot of fuel slows the rpm or causes the engine to stumble you should lower the needle to lean the mixture. If you do not have a primer, sell your EGT gauge and get one. Just kidding ,,,,,,, but do get one. These EGT gauges are notoriously inaccurate. Gene Z On Jul 17, 2007, at 9:58 AM, Richard Pike wrote: > > Been thinking about this and came up with a theory I'll throw out > for appropriate abuse: > While it is SOP that a correctly propped engine will give you good > EGT's and CHT's while bumping red line in level flight, what would > be your results if the prop diameter was slightly excessive for > your engine? > > Here is my thinking (your results may vary): if the diameter is > slightly too large, then in order to get the engine to turn it's > appropriate max RPM, (say 6500) you would need to dial in slightly > less pitch than normal, due to the excess load imposed by the > excess diameter. Then when reducing the RPM to cruise, the prop is > now somewhat under pitched, and the EGT is going to be abnormally > high, and the CHT abnormally low. > > So relative to your situation, any way you can borrow a 2 blade 60" > prop to compare and see what happens? Or even a 62" Warp or Ivo, > just in case Powerfin (with it's thicker airfoil) is causing a > slightly higher load, and requiring a slightly lower pitch? > > Richard Pike > MKIII N420P (420ldPoops) > > ----- Original Message ----- From: "Thom Riddle" > To: > Sent: Monday, July 16, 2007 1:05 PM > Subject: Kolb-List: FS 1 First Flight questions > > >> >> I flew the new-to-me FS 1 / 447 this morning and discovered a >> couple things that I could use some help with. >> 1) CHTs are low and EGTs are high during normal cruise speeds. >> They were in the normal range only during full power climb at Vy. >> >> My conundrum: I believe that by increasing the prop pitch a bit >> this should improve both the CHT and EGT readings. However, its >> current pitch gives me 6,500 rpm at WOT in level flight, which >> I've always thought was just about right. The prop is a 2-blade >> Powerfin x 62". >> >> What should I do? >> >> 2) With cruise power (5800 and higher), the elevator seems to be >> trimmed at higher IAS than I want or expect, i.e. it wants to >> descend with hands off. At lower power settings it seems to be >> trimmed at about 50 mph IAS, which I like. Is this an engine tilt >> (inclination) problem or something else? >> >> I don't recall either of these situations in my old early FS. It >> was trim neutral at all speeds and EGTs and CHTs stayed in normal >> even when descending at low power. >> >> Thanks for any guidance. >> >> -------- >> Thom in Buffalo >> N197BG FS1/447 >> do not archive >> -------------------- >> "Blind respect for authority is the greatest enemy of >> truth." >> Albert Einstein >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=124110#124110 >> >> >> >> >> >> >> >> >> >> > > ________________________________ Message 11 ____________________________________ Time: 10:19:18 AM PST US From: "Richard Girard" Subject: Re: Kolb-List: FS 1 First Flight questions Richard, Since we're talking theory I'd tend to agree with you, but as Yogi Berra once said, "In theory there is no difference between theory and practice, In practice, there is." Yes the prop unloads, but two things happen to ameliorate the engine temps. One, the prop disk of the larger prop counters the thrust loss produced by the lower pitch angle, so the relative amount of work done by the engine remains pretty much the same. Two, the bleed over in the mid to high range circuits of the carb, tends to lean out the carb as RPM drops. Rotax and Bing have worked this out by transition circuit design and jetting options. Rick On 7/17/07, Richard Pike wrote: > > > Been thinking about this and came up with a theory I'll throw out for > appropriate abuse: > While it is SOP that a correctly propped engine will give you good EGT's > and > CHT's while bumping red line in level flight, what would be your results > if > the prop diameter was slightly excessive for your engine? > > Here is my thinking (your results may vary): if the diameter is slightly > too > large, then in order to get the engine to turn it's appropriate max RPM, > (say 6500) you would need to dial in slightly less pitch than normal, due > to > the excess load imposed by the excess diameter. Then when reducing the RPM > to cruise, the prop is now somewhat under pitched, and the EGT is going to > be abnormally high, and the CHT abnormally low. > > So relative to your situation, any way you can borrow a 2 blade 60" prop > to > compare and see what happens? Or even a 62" Warp or Ivo, just in case > Powerfin (with it's thicker airfoil) is causing a slightly higher load, > and > requiring a slightly lower pitch? > > Richard Pike > MKIII N420P (420ldPoops) > > ----- Original Message ----- > From: "Thom Riddle" > To: > Sent: Monday, July 16, 2007 1:05 PM > Subject: Kolb-List: FS 1 First Flight questions > > > > > > I flew the new-to-me FS 1 / 447 this morning and discovered a couple > > things that I could use some help with. > > 1) CHTs are low and EGTs are high during normal cruise speeds. They were > > in the normal range only during full power climb at Vy. > > > > My conundrum: I believe that by increasing the prop pitch a bit this > > should improve both the CHT and EGT readings. However, its current pitch > > gives me 6,500 rpm at WOT in level flight, which I've always thought was > > just about right. The prop is a 2-blade Powerfin x 62". > > > > What should I do? > > > > 2) With cruise power (5800 and higher), the elevator seems to be trimmed > > at higher IAS than I want or expect, i.e. it wants to descend with hands > > off. At lower power settings it seems to be trimmed at about 50 mph IAS, > > which I like. Is this an engine tilt(inclination) problem or something > > else? > > > > I don't recall either of these situations in my old early FS. It was > trim > > neutral at all speeds and EGTs and CHTs stayed in normal even when > > descending at low power. > > > > Thanks for any guidance. > > > > -------- > > Thom in Buffalo > > N197BG FS1/447 > > do not archive > > -------------------- > > "Blind respect for authority is the greatest enemy of truth." > > Albert Einstein > > > > > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=124110#124110 > > > > > > > > > > > > > > > > > > > > > > > > -- Rick Girard "Ya'll drop on in" takes on a whole new meaning when you live at the airport. ________________________________ Message 12 ____________________________________ Time: 10:36:10 AM PST US From: "Richard Girard" Subject: Re: Kolb-List: Re: Kolb Mark III fuel tanks Before you make any decisions about changing tanks, try taking out one of your 5 gallon tanks. Once your plane is built, they are a bearcat to remove. When I asked Travis if the 6 gallon tanks were as much a PITA to get in and out as the 5 gallon, the answer was "Yeah, pretty much the same." If the footprint doesn't change, the only place to go for extra capacity is up, and that takes up the room required to turn the tank and drop it in. Rick On 7/17/07, Kirby Dennis Contr MDA/AL wrote: > > Dennis.Kirby@kirtland.af.mil> > > > "Bruce Chaisson" asked: << Does anyone know where to buy 8 gal. plastic > fuel tanks to replace the standard 5 gal ones? I know Kolb is selling 6 > gal replacements but have heard there are some 8 gal ones out there. >> > > Bruce - > > I, too, am interested in larger, drop-in replacement fuel tanks for my > Mark-III that will not require any cutting of structure to fit. I have > heard Quad City Challenger uses 8 (or 10?) gallon polyethylene fuel > tanks with the same square 10"x10" footprint that our Kolbs use. But I > have not verified this. Might be worth a call ... > > Dennis Kirby > Mark-3, 912ul > New Mexico > Do not archive > > -- Rick Girard "Ya'll drop on in" takes on a whole new meaning when you live at the airport. ________________________________ Message 13 ____________________________________ Time: 11:25:36 AM PST US From: "John Hauck" Subject: Re: Kolb-List: Two Stroke Prop and Carb Tuning your engine | at the RPM & loading you want to check for, leave it there for a couple | minutes, and then turn the engine off and then check it. Since there is a | difference in prop loading in flight than on the ground, that would mean | being right above a suitable strip to chop the engine, glide down, and then | pull the plug out and look at it. | | Richard Pike Richard: That is the way I did it. Past tense. Haven't done one in a while. I long while. Normally, the engineers that design and build these things know what they are doing. Two strokes are unique when combined with an airplane. Suddenly we have a propeller and prop loading. ;-( For most of us folks down here near sea level and up to 1,500 or 2,000 feet, that Rotax two stroke is jetted, timed, and equipped with the correct heat range spark plug to do the job, with nothing for the pilot/builder to do but dial in the correct pitch to load the prop. Always the same for me. WOT, straight and level flight, just bump the red line which is max continuous rpm for me because I fly with a prop that is not inflight adjustable. This will put my egt and cht right in the green arc on a Rotax two stroke, and other brands also. 912UL and 912ULS it is 5,500 rpm Rotax two strokes is 6,500 rpm Pushing the EGT redline to squeeze more power and less fuel burn is also pushing the engine failure factor with a two stroke, IMHO. john h mkIII ________________________________ Message 14 ____________________________________ Time: 11:34:19 AM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Flying characteristics- Kolb Firestar vs. Quicksilver Sprin anything I should | bear in mind on my first flight in the US? | | | -Dana Dana: A couple things: 1-Don't forget to fly the airplane. 2-Ultrastars do not fly below the stall speed, even though they will fly in a mush at a rapid rate of descent. 3-Gravity is not prejudice. Most folks that have trouble with an Ultrastar usually do so on landing. They are not accustomed to sitting out in the open, in front of the wing, get the airplane in a below stall speed mush, and spready the gear. Have personally witnessed this process several times over the years. Take care and have a fun flight. john h mkIII ________________________________ Message 15 ____________________________________ Time: 11:36:45 AM PST US From: "John Hauck" Subject: Re: Kolb-List: FS 1 First Flight questions Just | kidding ,,,,,,, but do get one. | | These EGT gauges are notoriously inaccurate. | | Gene Z Gene: You can get the same results, in flight, with the enricher. Not only on the two strokes, but it also works on the 912 series engines. Old fashioned, using the enricher on all my engines. john h mkIII ________________________________ Message 16 ____________________________________ Time: 01:28:42 PM PST US Subject: Kolb-List: Re: FS 1 First Flight questions From: "Thom Riddle" My my! What great responses this question has triggered. Keep them coming. Meanwhile, I'll tell you what I did this morning and the results. 1) I removed the spark plugs to see what story they would tell. They both looked a bit lean, not terribly so, but definitely lighter than the tan/light brown that I like to see. They were grayish white. This tells me that the engine was indeed running a bit leaner than it should. The gaps were in range and the plugs not worn much. However, the gaskets that come on the plugs were in place and should not be when using spark plug ring type CHT thermocouples, so I cut them off and applied anit-seize to the threads and reinstalled, and torqued them to spec. 2) I opened up the top of the carburetor and removed the contents. The clip was in the #3 groove, not the #2 groove as per Rotax recommendations. The clip and o-ring were below the white cup as it should be. If everything else in the carb is correct, then in #3 position, it should be running a bit on the rich side of optimum. I checked the jet needle number and it was correct. I did not go deeper into the carb but will on another day to see if the needle jet is the proper one and all other parts as well. I suspect the needle jet is the wrong number. I lowered the clip to the #4 groove (lowest/richest) and put all back together and took it for a spin. RESULTS: No appreciable change in EGTs or CHTs during WOT CLIMB... still in normal range. The EGTs in cruise rpm range were about 100 rpm lower than before moving the clip down to the last groove. Still higher than normal range but less than the MAX allowable temp. The CHTs did not change noticeably. The engine felt like it had more power and this was confirmed when I went to WOT in level flight. The max rpm is now 6,600 rpm where before it was 6,500 rpm. This confirms that the engine was running lean of peak power, at least at WOT. Next Steps: a. Increase pitch in prop to get 6,500 rpm at WOT level flight. b. Take carb apart and clean/inspect/check for proper jets etc. I'll post results of these steps as soon as possible but it will probably be a week before I get to do it. At least now, I can fly without fear that the EGTs are running too high in cruise. -------- Thom in Buffalo N197BG FS1/447 do not archive -------------------- "Blind respect for authority is the greatest enemy of truth." Albert Einstein Read this topic online here: http://forums.matronics.com/viewtopic.php?p=124428#124428 ________________________________ Message 17 ____________________________________ Time: 02:58:48 PM PST US Subject: Kolb-List: Mushy control stick From: "Paul Petty" Hey gang, After Charleys first flight in the Kolbra the only complaint he had was mushy responce from the stick. Well we figured alot of this is his lack of time in a Kolb type aircraft and his comparing it to the RV8 or even the jets he flys on a regular basis. After John H stopped by and it was discussed we or John rather found some movement in the control tube that sticks out the back and connects to the aileron push pull tubes. Right away we all agreed "There is your mush". Then it was suguested that more support be added back there. I started thinking of a way to fix this. To back up a bit remember than we changed the configuration of this area by running the control rod through a nylon bearing and making it fixed at the aft point. This leaves about 8" of the 4130 tube un-supported. However I got to really thinking about the steel tube and thought hmmm man there is no way that the 4130 steel tube is "flexing" that much. Now here is my thinking.. I am thinking that because the control tube is supported by a ridgid mount aft vs the slider for the flaperons, the flex or mush is coming from the lack of support at the other end of the control tube up near the rubber U-Joint. This makes perfect sence to me now that I think about it. The rubber U-joint is supported less than 3" in front but nothing of support to maybe 4' aft. This would make alot of stress on the U-joint and explain the flexing. Any of you guys think Im on the right track here? As soon as I can get back to the airplane and have some help I will confirm this therory and report back. The only reason for this post about this issue is this.... Other Kolbs with flapperons when the flapperons are extended may encounter the same mushy feel. might want to get a buddy to hold the aileron and another to move the stick side to side and watch the movenent at the U-Joint to see if the tube is trying to warp up/down or sideways. If my theroy is confirmed I will make a nylon bearing and mount it to the tail boom up close to the U-Joint to prevent this flexing. -------- Paul Petty Kolbra #12 Ms Dixie 912 UL 70" warp Read this topic online here: http://forums.matronics.com/viewtopic.php?p=124453#124453 ________________________________ Message 18 ____________________________________ Time: 03:02:11 PM PST US Subject: Kolb-List: Re: Mushy control stick From: "Paul Petty" PS.... This may be Kolbra only related and maybe only to Ms. Dixie due to mods so dont freak out! do not archive -------- Paul Petty Kolbra #12 Ms Dixie 912 UL 70" warp Read this topic online here: http://forums.matronics.com/viewtopic.php?p=124454#124454 ________________________________ Message 19 ____________________________________ Time: 04:22:03 PM PST US Subject: Kolb-List: Re: Kolb Mark III fuel tanks From: "JetPilot" This looks like a nice 10 gallon tank for replacement of the Kolb Fuel tanks. http://www.air-techinc.com/prod_cat_item.asp?categoryID=fueltanks&typ=exclusives&ID=1080 -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=124474#124474 ________________________________ Message 20 ____________________________________ Time: 06:23:41 PM PST US From: Eugene Zimmerman Subject: Re: Kolb-List: FS 1 First Flight questions Hey John, I believe your $.02 on the subject will probably buy as much as mine, :-) except perhaps at higher power settings. The enricher becomes decreasingly effective as the throttle is opened. In fact one reason some people have difficulty starting a cold engine using the enricher is because they open the throttle too far for the enricher to be effective. The enricher works different than a choke. I know I'm preaching to the choir with you. Gene, On Jul 17, 2007, at 2:36 PM, John Hauck wrote: > > > | If you do not have a primer, sell your EGT gauge and get one. > Just > > Gene: > > You can get the same results, in flight, with the enricher. Not only > on the two strokes, but it also works on the 912 series engines. > > Old fashioned, using the enricher on all my engines. > > john h > mkIII > > ________________________________ Message 21 ____________________________________ Time: 06:52:02 PM PST US From: "John Hauck" Subject: Re: Kolb-List: FS 1 First Flight questions | mine, :-) except perhaps at higher power settings. | The enricher becomes decreasingly effective as the throttle is opened. | | In fact one reason some people have difficulty starting a cold engine | using the enricher is because they open the throttle too far for the | enricher to be effective. The enricher works different than a choke. | I know I'm preaching to the choir with you. | | Gene, Gene: Reason I shared my little bit of info is because it worked with me and the 912UL. Did not feel like it was running as crisp as it should at 5,000 rpm cruise. Had had a problem with this same engine on my flight to Deadhorse, AK, in 1994. Was still working on the problem with less than ideal performance at cruise in colder climates. After I got back home, I experimented a lot trying to come up with a fix. While on a cross country flight to Mobile, AL, I got the idea to pull on the enricher. When I did, cruise speed increased 200 rpm. When I got back home, I pulled the carb piston, raised the needles a knotch, and my cold weather and warm weather midrange problem was solved. Wish I could have figured that out in Alaska. I would have made Point Barrow in 1994 instead of 2001. BTW: After I raised the needles in the 912, I checked the enricher at cruise rpm and the engine lost 200 rpm, indicating the enricher was making it go over rich. I might add, the 912 is tuned very close to max lean in midrange. Does not take much more leaning to piss off the 912 and make it act up. Definitely gets the pilots attention. I realize the enricher is not a choke. That is why I never had a need for primers. Never had a problem starting pull start, electric starter two strokes, and four strokes, using the correct procedure for starting. Do it right by the book and it works for me. john h mkIII ________________________________ Message 22 ____________________________________ Time: 09:48:03 PM PST US Subject: Kolb-List: Re: Mushy control stick From: "lucien" When I first started flying my FS II, I noticed the stick was rather "springy" in the aileron direction. It isn't what I'd call mushy, but definitely springy... Once I started relaxing and looking around a bit, I took it up and did some full-deflection wing rocking to get an idea of the aileron response. I noticed the ailerons hardly defected at cruise even with the stick against the stop to either side. I think some of the spring is twisting of the torque rod between the stick and the bellcrank in the back that attaches to the pushrods. Probably the rest is absorbed elsewhere, just in the general play in the aileron linkage. I don't think there are long portions of unsupported rod, but there might be towards the back.... So some of the flexing you're having could just be the tube itself? That's my only quarrel with the plane at all, and even so with gap seals on the ailerons there's still a good bit of aileron control. Otherwise, I love the design of the ailerons. Very simple and virtually no maintenance. No linkages, pullies or pushrods in the wing anywhere, it's all outside the plane for easy inspection and lubrication, etc. LS -------- LS FS II Read this topic online here: http://forums.matronics.com/viewtopic.php?p=124515#124515 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kolb-list Browse Digests http://www.matronics.com/digest/kolb-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.