---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Tue 10/12/10: 16 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:49 AM - AK-14P carb (Tom Johnson) 2. 08:24 AM - Re: AK-14P carb (Terry Calloway) 3. 09:04 AM - AK-14 carburettor (Richard Goode) 4. 09:25 AM - Re: AK-14P carb (bill wade) 5. 09:47 AM - Engine Failure in a Yak-50 (White3) 6. 11:07 AM - Re: AK-14P carb (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 7. 11:16 AM - Re: AK-14 carburettor (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 8. 12:00 PM - Re: AK-14 carburettor (Roger Kemp M.D.) 9. 12:49 PM - Re: AK-14 carburetor (George Coy) 10. 04:46 PM - Re: AK-14P carb (Eric Wobschall) 11. 04:55 PM - Re: AK-14 carburetor (A. Dennis Savarese) 12. 05:03 PM - Re: AK-14P carb (A. Dennis Savarese) 13. 05:38 PM - Re: Engine Failure in a Yak-50 (keithmckinley) 14. 06:09 PM - Re: AK-14 carburetor (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 15. 06:44 PM - Re: AK-14 carburetor (Eric Wobschall) 16. 07:32 PM - Re: AK-14 carburetor (Roger Kemp M.D.) ________________________________ Message 1 _____________________________________ Time: 07:49:14 AM PST US From: "Tom Johnson" Subject: Yak-List: AK-14P carb I have made numerous adjustments to my M14 carb jets and settings by reference to the Carb manual Task Cards and my Fuel Flow Indicator (JPI-450). Without a Fuel Flow indicator you are guessing (they are $300 to $500 installed and U need one). GENERALLY: in my experience: Main-Suction-Air-Compensating jet changes WOT fuel flow only for the most part. Compensating screw at back of carb adjust mid-range and messes up idle. Idle screw on co-pilots side changes idle only. I like my idle lean and target about 2.3 to 3.5 gph in the range of 25% to 40%. My engine is modified and I live in Arizona so I wanted more WOT fuel flow. I removed the Main-Suction-Air-Compensating jet which sits behind the diaphragm. As delivered it was a 1.9mm jet which is at the lean end. I experimented with several smaller (richer) jets and now have a 1.6mm jet. This yields me 42-44 gph at WOT takeoff 100+% RPM at Sea Level. I also made some turns to the mid-range clicker which sits directly at the back of the carb. It is a slotted screw with a bunch of holes around it and a thin metal cap. That thin metal cap has a pin which sits in one of the holes and limits the mid-range to 8 clicks. The task cards imply you should remove this cap and twist this screw all over the place. Don't do that. Just experiment within the 8 clicks from stop to stop of that pin. There are a total of 30some clicks and beyond the 30 be dragons. The pin in the thin metal cover restricts that to 8 clicks (one revolution). Adjusting that will whack your idle flow so you need to change your idle flow afterwards. I found a click richer needed about a click leaner on idle as a good start. I use my runup 70% setting to gauge where my mid-range is and I wish I never touched it. The clicks can be vague. Sometimes it is hard to tell if you clicked or not. Easy to get lost. Best results... try a different Top end jet to get you more WOT fuel flow if you want cooling. Get a nice lean idle for clean running. Leave the mid-range alone unless you need a change. My engine has the acceleration stumble which contributes to my intense masculinity and will not be changed. Mostly because I don't have any of the Acceleration Jets here...? Tj BY THE WAY... I found a certain position of my gills that gives me the lowest CHT and it aint wide open! --------------------------- Thomas Johnson Airpower Insurance, LLC 36 West Ocotillo Road Phoenix, AZ 85013-1235 Toll Free: 866-475-9199 Tel: 602-628-2701 Fax: 623-321-5843 www.airpowerinsurance.com E: tomjohnson@cox.net ________________________________ Message 2 _____________________________________ Time: 08:24:04 AM PST US Subject: Re: Yak-List: AK-14P carb From: Terry Calloway I have an AK-14P Carburetor for sale if anyone needs it. We replaced it with fuel injection. I have no idea what one should costs and would appreciate feedback on pricing as well. You can contact me off line at terrycalloway@mac.com if interested. Regards, tc ________________________________ Message 3 _____________________________________ Time: 09:04:27 AM PST US From: "Richard Goode" Subject: Yak-List: AK-14 carburettor Mark - I agree with everything that you say. I was not being pedantic about "suction jet" and "main jet" - it did seem to me that some people could be confused. My principal point is that the M14P can be made to run so much better if the carburettor is correctly tuned. Having said that, it is very difficult, with the different adjustments being interdependent. An obvious one is for the acceleration jet - if you are at idle and open the throttle, and then get a hesitation, it is EITHER to rich or to lean - and the black smoke if it is to rich will demonstrate that. I wish I were qualified to produce a step by step manual, but, quite frankly, I am not! BUT the official manual is pretty good, and does give a reasonably accurate picture and instructions of adjusting the carburettor. As Mark says, it is critical to know where you started from so that you can always go back to that position! Richard Goode Aerobatics Rhodds Farm Lyonshall Herefordshire HR5 3LW United Kingdom Tel: +44 (0) 1544 340120 Fax: +44 (0) 1544 340129 www.russianaeros.com ________________________________ Message 4 _____________________________________ Time: 09:25:33 AM PST US From: bill wade Subject: Re: Yak-List: AK-14P carb Terry how about a report on fuel injection. where did you get it it seems to be in the experimental stage at the factory for Sukoi, what is the price and availability does it really cut full burn, cooler head temps. Inquiring minds would like to know. Did you find a source for electronic ignition also Bill Wade ________________________________ From: Terry Calloway Sent: Tue, October 12, 2010 11:18:44 AM Subject: Re: Yak-List: AK-14P carb I have an AK-14P Carburetor for sale if anyone needs it. We replaced it with fuel injection. I have no idea what one should costs and would appreciate feedback on pricing as well. You can contact me off line at terrycalloway@mac.com if interested. Regards, tc ________________________________ Message 5 _____________________________________ Time: 09:47:07 AM PST US Subject: Yak-List: Engine Failure in a Yak-50 From: "White3" Check out this clip. Pilot loses all the oil from his engine while flying over some inhospitable terrain . He thought he was making a nice video to show his friends and family. Turns into one of the most exciting - and instructional - clips I've seen in a long time . http://www.bremont.com/mayday.php -------- It's not a hairy cow. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=315434#315434 ________________________________ Message 6 _____________________________________ Time: 11:07:59 AM PST US Subject: RE: Yak-List: AK-14P carb From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Thanks Tom, very valuable info. I especially was interested in your point of being able to accurately measure fuel flow while making these adjustments. Great point. I'm next door to you right now at Yuma, wave when you fly by. Mark ________________________________ From: owner-yak-list-server@matronics.com on behalf of Tom Johnson Sent: Tue 10/12/2010 10:45 AM Subject: Yak-List: AK-14P carb I have made numerous adjustments to my M14 carb jets and settings by reference to the Carb manual Task Cards and my Fuel Flow Indicator (JPI-450). Without a Fuel Flow indicator you are guessing (they are $300 to $500 installed and U need one). GENERALLY: in my experience: Main-Suction-Air-Compensating jet changes WOT fuel flow only for the most part. Compensating screw at back of carb adjust mid-range and messes up idle. Idle screw on co-pilots side changes idle only. I like my idle lean and target about 2.3 to 3.5 gph in the range of 25% to 40%. My engine is modified and I live in Arizona so I wanted more WOT fuel flow. I removed the Main-Suction-Air-Compensating jet which sits behind the diaphragm. As delivered it was a 1.9mm jet which is at the lean end. I experimented with several smaller (richer) jets and now have a 1.6mm jet. This yields me 42-44 gph at WOT takeoff 100+% RPM at Sea Level. I also made some turns to the mid-range clicker which sits directly at the back of the carb. It is a slotted screw with a bunch of holes around it and a thin metal cap. That thin metal cap has a pin which sits in one of the holes and limits the mid-range to 8 clicks. The task cards imply you should remove this cap and twist this screw all over the place. Don't do that. Just experiment within the 8 clicks from stop to stop of that pin. There are a total of 30some clicks and beyond the 30 be dragons. The pin in the thin metal cover restricts that to 8 clicks (one revolution). Adjusting that will whack your idle flow so you need to change your idle flow afterwards. I found a click richer needed about a click leaner on idle as a good start. I use my runup 70% setting to gauge where my mid-range is and I wish I never touched it. The clicks can be vague. Sometimes it is hard to tell if you clicked or not. Easy to get lost. Best results... try a different Top end jet to get you more WOT fuel flow if you want cooling. Get a nice lean idle for clean running. Leave the mid-range alone unless you need a change. My engine has the acceleration stumble which contributes to my intense masculinity and will not be changed. Mostly because I don't have any of the Acceleration Jets here...? Tj BY THE WAY... I found a certain position of my gills that gives me the lowest CHT and it aint wide open! --------------------------- Thomas Johnson Airpower Insurance, LLC 36 West Ocotillo Road Phoenix, AZ 85013-1235 Toll Free: 866-475-9199 Tel: 602-628-2701 Fax: 623-321-5843 www.airpowerinsurance.com E: tomjohnson@cox.net ________________________________ Message 7 _____________________________________ Time: 11:16:10 AM PST US Subject: RE: Yak-List: AK-14 carburettor From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Roger that Richard, thanks. I read Tom Johnson's note with interest as well. His engine is highly modified..... you ought to see the exhaust on that thing, not to mention the prop and a whole ton of other "stuff". He modifications really demanded that the carb be retuned. A valuable aid to him in this was an accurate fuel flow indicator. That sure would help a novice go about learning this thing. Thinking about it for my 50. It would also be interesting if a person could make a PORTABLE unit that could be attached to the aircraft being tuned. Just thinking out loud. Thanks (as usual) for sharing your experience and knowledge. Mark ________________________________ From: owner-yak-list-server@matronics.com on behalf of Richard Goode Sent: Tue 10/12/2010 12:01 PM Subject: Yak-List: AK-14 carburettor Mark - I agree with everything that you say. I was not being pedantic about "suction jet" and "main jet" - it did seem to me that some people could be confused. My principal point is that the M14P can be made to run so much better if the carburettor is correctly tuned. Having said that, it is very difficult, with the different adjustments being interdependent. An obvious one is for the acceleration jet - if you are at idle and open the throttle, and then get a hesitation, it is EITHER to rich or to lean - and the black smoke if it is to rich will demonstrate that. I wish I were qualified to produce a step by step manual, but, quite frankly, I am not! BUT the official manual is pretty good, and does give a reasonably accurate picture and instructions of adjusting the carburettor. As Mark says, it is critical to know where you started from so that you can always go back to that position! Richard Goode Aerobatics Rhodds Farm Lyonshall Herefordshire HR5 3LW United Kingdom Tel: +44 (0) 1544 340120 Fax: +44 (0) 1544 340129 www.russianaeros.com ________________________________ Message 8 _____________________________________ Time: 12:00:01 PM PST US From: "Roger Kemp M.D." Subject: RE: Yak-List: AK-14 carburettor Can easily be done just need the fuel sender in line with the fuel line that you will need to manufacture with appropriate RU banjo fittings. Then it is the 12 volt electrical source and the JP analyzer or other appropriate fuel flow analyzer. What the heck, it is only money. Doc It would also be interesting if a person could make a PORTABLE unit that could be attached to the aircraft being tuned. Just thinking out loud. Thanks (as usual) for sharing your experience and knowledge. Mark ________________________________ Message 9 _____________________________________ Time: 12:49:14 PM PST US From: "George Coy" Subject: RE: Yak-List: AK-14 carburetor Just a word of caution about fuel flow sending units. We are aware of two incidents and possibly an accident where U.S. hose was substituted for the Russian hose. In these cases the cause of the problem was diagnosed as a rubber "flap" that was cut on the inside diameter of the hose during installation of the Russian Banjo fitting. It is almost impossible to inspect the hose for an internal flap at the Banjo fitting. The Banjo fitting is the fitting at the top of the "black" fine filter located on the firewall on the top right hand (sitting in the cockpit) side of the firewall. This is the line from the fine filter to the carburetor. This is also the line where the fuel flow sensors are usually are installed. The two incidents we are aware of had normal operation for run up but severely reduced fuel flow at take off power settings. They were very difficult to diagnose as well. The fuel flow sensors are usually a "Paddle Wheel" and are located in the line to the carburetor. Any contamination in the line (rubber chips from a new hose etc) can jam the "paddle wheel" and cause reduced fuel flow as well. George Coy CAS Ltd. 714 Airport Rd. Swanton VT 05488 802-868-5633 off 802-363-5782 cell george.coy@gmail.com http://coyafct.com/ SKYPE george.coy ________________________________ Message 10 ____________________________________ Time: 04:46:06 PM PST US From: Eric Wobschall Subject: Re: Yak-List: AK-14P carb WTF is WOT? Wide open throttle, right? On Oct 12, 2010, at 10:45 AM, Tom Johnson wrote: > > I have made numerous adjustments to my M14 carb jets and settings by > reference to the Carb manual Task Cards and my Fuel Flow Indicator > (JPI-450). Without a Fuel Flow indicator you are guessing (they are > $300 to > $500 installed and U need one). > > GENERALLY: in my experience: > Main-Suction-Air-Compensating jet changes WOT fuel flow only for the > most > part. > Compensating screw at back of carb adjust mid-range and messes up > idle. > Idle screw on co-pilots side changes idle only. > > I like my idle lean and target about 2.3 to 3.5 gph in the range of > 25% to > 40%. > > My engine is modified and I live in Arizona so I wanted more WOT > fuel flow. > I removed the Main-Suction-Air-Compensating jet which sits behind the > diaphragm. > As delivered it was a 1.9mm jet which is at the lean end. > > I experimented with several smaller (richer) jets and now have a > 1.6mm jet. > This yields me 42-44 gph at WOT takeoff 100+% RPM at Sea Level. > > I also made some turns to the mid-range clicker which sits directly > at the > back of the carb. It is a slotted screw with a bunch of holes > around it and > a thin metal cap. That thin metal cap has a pin which sits in one > of the > holes and limits the mid-range to 8 clicks. The task cards imply > you should > remove this cap and twist this screw all over the place. > Don't do that. > > Just experiment within the 8 clicks from stop to stop of that pin. > There are a total of 30some clicks and beyond the 30 be dragons. > The pin in the thin metal cover restricts that to 8 clicks (one > revolution). > Adjusting that will whack your idle flow so you need to change your > idle > flow afterwards. > I found a click richer needed about a click leaner on idle as a good > start. > I use my runup 70% setting to gauge where my mid-range is and I wish > I never > touched it. > > The clicks can be vague. Sometimes it is hard to tell if you > clicked or > not. > Easy to get lost. > > Best results... try a different Top end jet to get you more WOT fuel > flow if > you want cooling. > Get a nice lean idle for clean running. > Leave the mid-range alone unless you need a change. > > My engine has the acceleration stumble which contributes to my intense > masculinity and will not be changed. > Mostly because I don't have any of the Acceleration Jets here...? > > Tj > > BY THE WAY... I found a certain position of my gills that gives me the > lowest CHT and it aint wide open! > > > --------------------------- > Thomas Johnson > Airpower Insurance, LLC > 36 West Ocotillo Road > Phoenix, AZ 85013-1235 > Toll Free: 866-475-9199 > Tel: 602-628-2701 > Fax: 623-321-5843 > www.airpowerinsurance.com > E: tomjohnson@cox.net > > ________________________________ Message 11 ____________________________________ Time: 04:55:12 PM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: AK-14 carburetor Good points George (as always). One additional point with regard to the fuel flow transducer, the paddle wheel which is inside the fuel flow transducer can also be easily damaged by rubber chips disintegrating from the "flap" in hose. On the JPI FS-450, that's an over-$200 replacement part. Dennis ----- Original Message ----- From: George Coy To: yak-list@matronics.com Sent: Tuesday, October 12, 2010 2:46 PM Subject: RE: Yak-List: AK-14 carburetor Just a word of caution about fuel flow sending units. We are aware of two incidents and possibly an accident where U.S. hose was substituted for the Russian hose. In these cases the cause of the problem was diagnosed as a rubber "flap" that was cut on the inside diameter of the hose during installation of the Russian Banjo fitting. It is almost impossible to inspect the hose for an internal flap at the Banjo fitting. The Banjo fitting is the fitting at the top of the "black" fine filter located on the firewall on the top right hand (sitting in the cockpit) side of the firewall. This is the line from the fine filter to the carburetor. This is also the line where the fuel flow sensors are usually are installed. The two incidents we are aware of had normal operation for run up but severely reduced fuel flow at take off power settings. They were very difficult to diagnose as well. The fuel flow sensors are usually a "Paddle Wheel" and are located in the line to the carburetor. Any contamination in the line (rubber chips from a new hose etc) can jam the "paddle wheel" and cause reduced fuel flow as well. George Coy CAS Ltd. 714 Airport Rd. Swanton VT 05488 802-868-5633 off 802-363-5782 cell george.coy@gmail.com http://coyafct.com/ SKYPE george.coy ________________________________ Message 12 ____________________________________ Time: 05:03:31 PM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: AK-14P carb Yep! Dennis ----- Original Message ----- From: Eric Wobschall To: yak-list@matronics.com Sent: Tuesday, October 12, 2010 6:42 PM Subject: Re: Yak-List: AK-14P carb WTF is WOT? Wide open throttle, right? On Oct 12, 2010, at 10:45 AM, Tom Johnson wrote: > > I have made numerous adjustments to my M14 carb jets and settings by > reference to the Carb manual Task Cards and my Fuel Flow Indicator > (JPI-450). Without a Fuel Flow indicator you are guessing (they are > $300 to > $500 installed and U need one). > > GENERALLY: in my experience: > Main-Suction-Air-Compensating jet changes WOT fuel flow only for the > most > part. > Compensating screw at back of carb adjust mid-range and messes up > idle. > Idle screw on co-pilots side changes idle only. > > I like my idle lean and target about 2.3 to 3.5 gph in the range of > 25% to > 40%. > > My engine is modified and I live in Arizona so I wanted more WOT > fuel flow. > I removed the Main-Suction-Air-Compensating jet which sits behind the > diaphragm. > As delivered it was a 1.9mm jet which is at the lean end. > > I experimented with several smaller (richer) jets and now have a > 1.6mm jet. > This yields me 42-44 gph at WOT takeoff 100+% RPM at Sea Level. > > I also made some turns to the mid-range clicker which sits directly > at the > back of the carb. It is a slotted screw with a bunch of holes > around it and > a thin metal cap. That thin metal cap has a pin which sits in one > of the > holes and limits the mid-range to 8 clicks. The task cards imply > you should > remove this cap and twist this screw all over the place. > Don't do that. > > Just experiment within the 8 clicks from stop to stop of that pin. > There are a total of 30some clicks and beyond the 30 be dragons. > The pin in the thin metal cover restricts that to 8 clicks (one > revolution). > Adjusting that will whack your idle flow so you need to change your > idle > flow afterwards. > I found a click richer needed about a click leaner on idle as a good > start. > I use my runup 70% setting to gauge where my mid-range is and I wish > I never > touched it. > > The clicks can be vague. Sometimes it is hard to tell if you > clicked or > not. > Easy to get lost. > > Best results... try a different Top end jet to get you more WOT fuel > flow if > you want cooling. > Get a nice lean idle for clean running. > Leave the mid-range alone unless you need a change. > > My engine has the acceleration stumble which contributes to my intense > masculinity and will not be changed. > Mostly because I don't have any of the Acceleration Jets here...? > > Tj > > BY THE WAY... I found a certain position of my gills that gives me the > lowest CHT and it aint wide open! > > > --------------------------- > Thomas Johnson > Airpower Insurance, LLC > 36 West Ocotillo Road > Phoenix, AZ 85013-1235 > Toll Free: 866-475-9199 > Tel: 602-628-2701 > Fax: 623-321-5843 > www.airpowerinsurance.com > E: tomjohnson@cox.net > > > > > ________________________________ Message 13 ____________________________________ Time: 05:38:20 PM PST US Subject: Yak-List: Re: Engine Failure in a Yak-50 From: "keithmckinley" thanks for sharing this! Nice job!!! -------- Keith McKinley 700HS KFIT Read this topic online here: http://forums.matronics.com/viewtopic.php?p=315497#315497 ________________________________ Message 14 ____________________________________ Time: 06:09:49 PM PST US Subject: RE: Yak-List: AK-14 carburetor From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Thanks for saving my ass George. Borescope from work will be used on this one! Mark ________________________________ From: owner-yak-list-server@matronics.com on behalf of George Coy Sent: Tue 10/12/2010 3:46 PM Subject: RE: Yak-List: AK-14 carburetor Just a word of caution about fuel flow sending units. We are aware of two incidents and possibly an accident where U.S. hose was substituted for the Russian hose. In these cases the cause of the problem was diagnosed as a rubber "flap" that was cut on the inside diameter of the hose during installation of the Russian Banjo fitting. It is almost impossible to inspect the hose for an internal flap at the Banjo fitting. The Banjo fitting is the fitting at the top of the "black" fine filter located on the firewall on the top right hand (sitting in the cockpit) side of the firewall. This is the line from the fine filter to the carburetor. This is also the line where the fuel flow sensors are usually are installed. The two incidents we are aware of had normal operation for run up but severely reduced fuel flow at take off power settings. They were very difficult to diagnose as well. The fuel flow sensors are usually a "Paddle Wheel" and are located in the line to the carburetor. Any contamination in the line (rubber chips from a new hose etc) can jam the "paddle wheel" and cause reduced fuel flow as well. George Coy CAS Ltd. 714 Airport Rd. Swanton VT 05488 802-868-5633 off 802-363-5782 cell george.coy@gmail.com http://coyafct.com/ SKYPE george.coy ________________________________ Message 15 ____________________________________ Time: 06:44:21 PM PST US From: Eric Wobschall Subject: Re: Yak-List: AK-14 carburetor I also had a hose flapper from American hose in the RU fittings. Devil of a time figuring out what my surging was about. Turned out to be a rubber clump approximately the size of your head. Amazing it ran like that. On Oct 12, 2010, at 9:04 PM, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E wrote: > Point, MALS-14 64E" > > Thanks for saving my ass George. Borescope from work will be used > on this one! > > Mark > > > ________________________________ > > From: owner-yak-list-server@matronics.com on behalf of George Coy > Sent: Tue 10/12/2010 3:46 PM > To: yak-list@matronics.com > Subject: RE: Yak-List: AK-14 carburetor > > > > Just a word of caution about fuel flow sending units. We are > aware > of two incidents and possibly an accident where U.S. hose was > substituted > for the Russian hose. In these cases the cause of the problem was > diagnosed > as a rubber "flap" that was cut on the inside diameter of the hose > during > installation of the Russian Banjo fitting. It is almost impossible to > inspect the hose for an internal flap at the Banjo fitting. > The Banjo fitting is the fitting at the top of the "black" fine > filter located on the firewall on the top right hand (sitting in the > cockpit) side of the firewall. This is the line from the fine filter > to the > carburetor. This is also the line where the fuel flow sensors are > usually > are installed. > The two incidents we are aware of had normal operation for > run up > but severely reduced fuel flow at take off power settings. They were > very > difficult to diagnose as well. > The fuel flow sensors are usually a "Paddle Wheel" and are > located > in the line to the carburetor. Any contamination in the line (rubber > chips > from a new hose etc) can jam the "paddle wheel" and cause reduced > fuel flow > as well. > > > George Coy > CAS Ltd. > 714 Airport Rd. > Swanton VT 05488 > 802-868-5633 off > 802-363-5782 cell > george.coy@gmail.com > http://coyafct.com/ > SKYPE george.coy > > ________________________________ Message 16 ____________________________________ Time: 07:32:29 PM PST US From: "Roger Kemp M.D." Subject: RE: Yak-List: AK-14 carburetor Been there. Done that. Got the T shirt. Dead stick the 50 back onto runway after engine quit at 50 ft on T.O. Flapper fragments in the fine finger screen from the "NEW" RU fuel line after IRAN in RU before shipping her over. The only hint was a sudden hesitation at 70% run up one time. There were fragments of the inner fuel lining in the finger screen in the carb. At high flow the flapper fragments would block the fuel flow into the carb. Doc -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of George Coy Sent: Tuesday, October 12, 2010 2:46 PM Subject: RE: Yak-List: AK-14 carburetor Just a word of caution about fuel flow sending units. We are aware of two incidents and possibly an accident where U.S. hose was substituted for the Russian hose. In these cases the cause of the problem was diagnosed as a rubber "flap" that was cut on the inside diameter of the hose during installation of the Russian Banjo fitting. It is almost impossible to inspect the hose for an internal flap at the Banjo fitting. The Banjo fitting is the fitting at the top of the "black" fine filter located on the firewall on the top right hand (sitting in the cockpit) side of the firewall. This is the line from the fine filter to the carburetor. This is also the line where the fuel flow sensors are usually are installed. The two incidents we are aware of had normal operation for run up but severely reduced fuel flow at take off power settings. They were very difficult to diagnose as well. The fuel flow sensors are usually a "Paddle Wheel" and are located in the line to the carburetor. Any contamination in the line (rubber chips from a new hose etc) can jam the "paddle wheel" and cause reduced fuel flow as well. George Coy CAS Ltd. 714 Airport Rd. Swanton VT 05488 802-868-5633 off 802-363-5782 cell george.coy@gmail.com http://coyafct.com/ SKYPE george.coy ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message yak-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Yak-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/yak-list Browse Digests http://www.matronics.com/digest/yak-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.