---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Wed 07/05/06: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:23 AM - Re: Yak 55M Air Start (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 2. 04:27 AM - Re: Oil Temperature Guage on Yak 55M (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 3. 05:40 AM - Re: Yak 55M Air Start (Scott Poehlmann) 4. 05:59 AM - Re: Yak 55M Air Start (Rob Kent) 5. 07:13 AM - Re: Yak 55M Air Start (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E) 6. 07:34 AM - The current Russian military trainer (Richard Goode) 7. 07:44 AM - Log book (cjpilot710@aol.com) 8. 08:43 AM - Re: The current Russian military trainer (Buzzard Aviation) ________________________________ Message 1 _____________________________________ Time: 04:23:50 AM PST US From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Subject: RE: Yak-List: Yak 55M Air Start Doug, I do not believe that the YAK-55 uses an electrically actuated air start solenoid, such as the 50 and 52 does. Instead I believe it uses the same manually activated valve as do the Sukhoi's. If this is indeed the case, Scott... your most likely cause is corrosion in the air start valve itself OR...and this is a real sneaky problem..... someone in the past has replaced the rubber pad in the air start valve with the wrong one! This problem will drive you NUTS and you have all the symtoms. You really do not have to remove the whole thing to work on it.... although I have never worked on a YAK-55, so I am unsure of the mounting arrangement. If you can get to the back of the thing easily, you can just pull it apart from the rear and leave the main assy. in place. When you take the rear big nut off, you may have to reach into the hole with a tool to get the shuttle to slide out if there is corrosion. Anyway, pulling it that way allows you from having to remove the electrical contacts that activate your voltage booster assy. for the MAGS, which some people refer to as the shower of sparks... which it really isn't. If that is impossible, then simply pull the whole thing out of there and take it apart. Inside you will find a spring... which often breaks from corrosion..... a shuttle valve with ridges on the outside.... clean it and the barrel of the valve carefully.... and on the end of the shuttle you will find that one end is open... hollow, and the other end has a little metal tit sticking out right from the middle. The little metal tit should have a black rubber seal surrounding it. The seal should look like a hard rubber gasket.. not an "O" ring, but instead almost like a thick hard rubber washer. This piece MUST ... and I repeat MUST have a small hole right in the middle of it that allows the metal tit from the shuttle valve itself to stick through it. If you happen to have a hard rubber gasket... round but with no hole in the middle of it... you have found your problem. If it does have a hole in the middle of it... then check for broken weak spring, and/or corrosion in the valve body itself preventing the shuttle from moving freely. Here is how this happens... There is an over-pressure relief valve on most Russian aircraft that works ALMOST exactly like the start valve on your YAK-55. The rubber bushing/seal in it is perfectly round with no hole in the middle and is on the end of a shuttle valve ALMOST but not exactly identical again to the start valve. There is a kit to replace the bushing on the over-pressure relief valve. Many people have mistakenly made the assumption that this same bushing/rubber seal can also replace the one in the start valve. Actually it can.... as long as you carefully put a hole directly in the middle of it so that the metal tit that sticks out from the end of the start valve shuttle can poke through.... otherwise you have symtoms very close to what you are experiencing. It's a long shot... but someone might have done this to your airplane. I have never seen a spider distributor that worked cold, but won't work hot. Those things are devices made by the devil though.... so I guess it is possible! WARNING! Do NOT pull that thing out of your aircraft until you are DARN DARN SURE that it is bad. Expect a few DAYS worth of effort to get it back in and working again. A quick check here would be to simply take the air line off right at the start lever that leads to the engine. Push the start lever. Got plenty of air? No? That pretty much answers your question. Best of Luck, Mark Bitterlich -----Original Message----- [mailto:owner-yak-list-server@matronics.com]On Behalf Of doug sapp Sent: Tuesday, July 04, 2006 12:16 Scott, Have you done this test yet? Next time the problem occurs: Disconnect the hose which runs FROM the start solenoid TO the start spider on the engine, then hit the button and confirm that the start solenoid is functioning and you DO have air at the start spider. If you do have air at the start spider then timing in the start spider has somehow slipped or changed enough to not allow the air to pass and for the engine to start, if you don't have air at the start spider you most likely have an intermittent start solenoid, which is not all that uncommon. To prove this check to make sure you are in fact delivering air pressure TO the start solenoid. My guess it that you will find that your start solenoid is intermittent. If the problem turns out to be timing I am sure that Dennis can help, if the problem is in the start solenoid I have them for the CJ6 and I do think they just might be the same. Hope this helps. Always Yakin, Doug Sapp -----Original Message----- [mailto:owner-yak-list-server@matronics.com]On Behalf Of Scott Poehlmann Sent: Monday, July 03, 2006 7:58 PM Hi All, Have an interesting and troublesome problem. For the last several weeks I have had trouble with the starting the Yak. The scenario is always like this: go out, check the air (650-750 psi), turn the prop through (15 blades), prime, pull the prop through (15 blades), get in, prime, start without any trouble. Go fly acro, mostly working on Advanced-level figures, rollers, inverted spins, half-snaps, with the occaisional run through an Intermediate Known or Free, land, taxi to the pump, fill gas, check the air (again 650-750 psi), get in, prime, hit the starter and nothing happens. I mean NOTHING, no hiss of air, no prop moving, and certainly no start. Rarely I can get the prop to just barely move (less than 1/3 blade), but otherwise nothing. Pulling the prop through in this condition demonstrates that it isn't hydro-locked. My troubleshooting has run like this: 1) There is air in the system. 2) The prop is not hydro-locked. 3) The primer works. 4) The air start valve is clean and in good condition (took it out, cleaned and inspected it last week...). Now I have run out of ideas. Could the air distributor be at fault? If so how, and how do I check it, and how do I sort it out. Ideas? Voodoo spells? Secret Russian code words? I'm up for anything that will work here... Thanks, Scott ________________________________ Message 2 _____________________________________ Time: 04:27:53 AM PST US From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Subject: RE: Yak-List: Oil Temperature Guage on Yak 55M --> Yak-List message posted by: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Just wanted to concur with everyone else on this one. Everytime I have seen this problem it has been the sending unit, or a bad electrical contact on the plug AT the sending unit (as in an open as already described). Also, as has also been mentioned... you can simply swap it out with the carb temp probe to check it... both are identical. Not adding anything new... just double confirming that what has already been mentioned is also exactly what I have found in the past as well on more than one aircraft. Mark Bitterlich -----Original Message----- [mailto:owner-yak-list-server@matronics.com]On Behalf Of Royden Heays Sent: Sunday, July 02, 2006 13:33 --> Yak-List message posted by: "Royden Heays" After many hundereds of hours of well behaved indications the oil temperature guage on my Yak 55M has begun to flicker right up to full deflection. This occurred for the first time yesterday on start up when the oil was known to be cool. The guage is the standard Russian guage that goes with the M14P on all the Yaks I have seen. Any pointers? Royden Heays C-GRED ________________________________ Message 3 _____________________________________ Time: 05:40:33 AM PST US From: "Scott Poehlmann" Subject: Re: Yak-List: Yak 55M Air Start Hi Mark, Your description of the valve is perfect. That is indeed how the air start on the -55M works. The valve is located on the far lower left of the panel, with a bulkhead below it, and is accessible only through the hole where the floating panel attaches (and around a slightly more than 90 degree corner...), thus must be removed to service in any meaningful way (unless one is a three foot tall, double-jointed elf with extremely long fingers...). I've had this valve out, and apart and can report that the rubbers are correct, with the appropriate holes, and in good condition. As is in the inside of the valve and the spring--very minimal corrosion which came off with just a little bit of cleaning.I am guessing at this point that the problem is hose/line related. The valve connects to a hard line which runs forward to the firewall, and thence to a Russian hose from the firewall to the inlet on the distributor. I will try removing the connector at the firewall and see if I get air there next time I have the problem (I tried to recreate the problem yesterday, but of course, the engine starts perfectly now...). I am hoping at this point that the problem is hose related. I REALLY don't want to futz with the distributor... Thanks, Scott ----- Original Message ----- From: Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E To: yak-list@matronics.com Sent: Wednesday, 05 July, 2006 05:21 Subject: RE: Yak-List: Yak 55M Air Start Doug, I do not believe that the YAK-55 uses an electrically actuated air start solenoid, such as the 50 and 52 does. Instead I believe it uses the same manually activated valve as do the Sukhoi's. If this is indeed the case, Scott... your most likely cause is corrosion in the air start valve itself OR...and this is a real sneaky problem..... someone in the past has replaced the rubber pad in the air start valve with the wrong one! This problem will drive you NUTS and you have all the symtoms. You really do not have to remove the whole thing to work on it.... although I have never worked on a YAK-55, so I am unsure of the mounting arrangement. If you can get to the back of the thing easily, you can just pull it apart from the rear and leave the main assy. in place. When you take the rear big nut off, you may have to reach into the hole with a tool to get the shuttle to slide out if there is corrosion. Anyway, pulling it that way allows you from having to remove the electrical contacts that activate your voltage booster assy. for the MAGS, which some people refer to as the shower of sparks... which it really isn't. If that is impossible, then simply pull the whole thing out of there and take it apart. Inside you will find a spring... which often breaks from corrosion..... a shuttle valve with ridges on the outside.... clean it and the barrel of the valve carefully.... and on the end of the shuttle you will find that one end is open... hollow, and the other end has a little metal tit sticking out right from the middle. The little metal tit should have a black rubber seal surrounding it. The seal should look like a hard rubber gasket.. not an "O" ring, but instead almost like a thick hard rubber washer. This piece MUST ... and I repeat MUST have a small hole right in the middle of it that allows the metal tit from the shuttle valve itself to stick through it. If you happen to have a hard rubber gasket... round but with no hole in the middle of it... you have found your problem. If it does have a hole in the middle of it... then check for broken weak spring, and/or corrosion in the valve body itself preventing the shuttle from moving freely. Here is how this happens... There is an over-pressure relief valve on most Russian aircraft that works ALMOST exactly like the start valve on your YAK-55. The rubber bushing/seal in it is perfectly round with no hole in the middle and is on the end of a shuttle valve ALMOST but not exactly identical again to the start valve. There is a kit to replace the bushing on the over-pressure relief valve. Many people have mistakenly made the assumption that this same bushing/rubber seal can also replace the one in the start valve. Actually it can.... as long as you carefully put a hole directly in the middle of it so that the metal tit that sticks out from the end of the start valve shuttle can poke through.... otherwise you have symtoms very close to what you are experiencing. It's a long shot... but someone might have done this to your airplane. I have never seen a spider distributor that worked cold, but won't work hot. Those things are devices made by the devil though.... so I guess it is possible! WARNING! Do NOT pull that thing out of your aircraft until you are DARN DARN SURE that it is bad. Expect a few DAYS worth of effort to get it back in and working again. A quick check here would be to simply take the air line off right at the start lever that leads to the engine. Push the start lever. Got plenty of air? No? That pretty much answers your question. Best of Luck, Mark Bitterlich -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of doug sapp Sent: Tuesday, July 04, 2006 12:16 To: yak-list@matronics.com Subject: RE: Yak-List: Yak 55M Air Start Scott, Have you done this test yet? Next time the problem occurs: Disconnect the hose which runs FROM the start solenoid TO the start spider on the engine, then hit the button and confirm that the start solenoid is functioning and you DO have air at the start spider. If you do have air at the start spider then timing in the start spider has somehow slipped or changed enough to not allow the air to pass and for the engine to start, if you don't have air at the start spider you most likely have an intermittent start solenoid, which is not all that uncommon. To prove this check to make sure you are in fact delivering air pressure TO the start solenoid. My guess it that you will find that your start solenoid is intermittent. If the problem turns out to be timing I am sure that Dennis can help, if the problem is in the start solenoid I have them for the CJ6 and I do think they just might be the same. Hope this helps. Always Yakin, Doug Sapp -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of Scott Poehlmann Sent: Monday, July 03, 2006 7:58 PM To: yak-list@matronics.com Subject: Yak-List: Yak 55M Air Start Hi All, Have an interesting and troublesome problem. For the last several weeks I have had trouble with the starting the Yak. The scenario is always like this: go out, check the air (650-750 psi), turn the prop through (15 blades), prime, pull the prop through (15 blades), get in, prime, start without any trouble. Go fly acro, mostly working on Advanced-level figures, rollers, inverted spins, half-snaps, with the occaisional run through an Intermediate Known or Free, land, taxi to the pump, fill gas, check the air (again 650-750 psi), get in, prime, hit the starter and nothing happens. I mean NOTHING, no hiss of air, no prop moving, and certainly no start. Rarely I can get the prop to just barely move (less than 1/3 blade), but otherwise nothing. Pulling the prop through in this condition demonstrates that it isn't hydro-locked. My troubleshooting has run like this: 1) There is air in the system. 2) The prop is not hydro-locked. 3) The primer works. 4) The air start valve is clean and in good condition (took it out, cleaned and inspected it last week...). Now I have run out of ideas. Could the air distributor be at fault? If so how, and how do I check it, and how do I sort it out. Ideas? Voodoo spells? Secret Russian code words? I'm up for anything that will work here... Thanks, Scott ________________________________ Message 4 _____________________________________ Time: 05:59:07 AM PST US From: "Rob Kent" Subject: Re: Yak-List: Yak 55M Air Start Mark is correct. The Yak-55 does not use an electric start solenoid. The diagrams below should help with Marks description. https://systemlinux.co.uk/images/555500-00.jpg Yak-55 air system diagram (without air compressor) https://systemlinux.co.uk/images/555500-100.jpg Yak-55 push to start air valve https://systemlinux.co.uk/images/42.5300.8.071.000.jpg Sukhoi push to start air valve Regards Rob Kent Stores Manager WLAC - Russian Engineering www.wlacrussianeng.co.uk Tel: +44 1628 829 165 Fax: +44 1628 828 961 ----- Original Message ----- From: Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E To: yak-list@matronics.com Sent: Wednesday, July 05, 2006 12:21 PM Subject: RE: Yak-List: Yak 55M Air Start Doug, I do not believe that the YAK-55 uses an electrically actuated air start solenoid, such as the 50 and 52 does. Instead I believe it uses the same manually activated valve as do the Sukhoi's. If this is indeed the case, Scott... your most likely cause is corrosion in the air start valve itself OR...and this is a real sneaky problem..... someone in the past has replaced the rubber pad in the air start valve with the wrong one! This problem will drive you NUTS and you have all the symtoms. You really do not have to remove the whole thing to work on it.... although I have never worked on a YAK-55, so I am unsure of the mounting arrangement. If you can get to the back of the thing easily, you can just pull it apart from the rear and leave the main assy. in place. When you take the rear big nut off, you may have to reach into the hole with a tool to get the shuttle to slide out if there is corrosion. Anyway, pulling it that way allows you from having to remove the electrical contacts that activate your voltage booster assy. for the MAGS, which some people refer to as the shower of sparks... which it really isn't. If that is impossible, then simply pull the whole thing out of there and take it apart. Inside you will find a spring... which often breaks from corrosion..... a shuttle valve with ridges on the outside.... clean it and the barrel of the valve carefully.... and on the end of the shuttle you will find that one end is open... hollow, and the other end has a little metal tit sticking out right from the middle. The little metal tit should have a black rubber seal surrounding it. The seal should look like a hard rubber gasket.. not an "O" ring, but instead almost like a thick hard rubber washer. This piece MUST ... and I repeat MUST have a small hole right in the middle of it that allows the metal tit from the shuttle valve itself to stick through it. If you happen to have a hard rubber gasket... round but with no hole in the middle of it... you have found your problem. If it does have a hole in the middle of it... then check for broken weak spring, and/or corrosion in the valve body itself preventing the shuttle from moving freely. Here is how this happens... There is an over-pressure relief valve on most Russian aircraft that works ALMOST exactly like the start valve on your YAK-55. The rubber bushing/seal in it is perfectly round with no hole in the middle and is on the end of a shuttle valve ALMOST but not exactly identical again to the start valve. There is a kit to replace the bushing on the over-pressure relief valve. Many people have mistakenly made the assumption that this same bushing/rubber seal can also replace the one in the start valve. Actually it can.... as long as you carefully put a hole directly in the middle of it so that the metal tit that sticks out from the end of the start valve shuttle can poke through.... otherwise you have symtoms very close to what you are experiencing. It's a long shot... but someone might have done this to your airplane. I have never seen a spider distributor that worked cold, but won't work hot. Those things are devices made by the devil though.... so I guess it is possible! WARNING! Do NOT pull that thing out of your aircraft until you are DARN DARN SURE that it is bad. Expect a few DAYS worth of effort to get it back in and working again. A quick check here would be to simply take the air line off right at the start lever that leads to the engine. Push the start lever. Got plenty of air? No? That pretty much answers your question. Best of Luck, Mark Bitterlich -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of doug sapp Sent: Tuesday, July 04, 2006 12:16 To: yak-list@matronics.com Subject: RE: Yak-List: Yak 55M Air Start Scott, Have you done this test yet? Next time the problem occurs: Disconnect the hose which runs FROM the start solenoid TO the start spider on the engine, then hit the button and confirm that the start solenoid is functioning and you DO have air at the start spider. If you do have air at the start spider then timing in the start spider has somehow slipped or changed enough to not allow the air to pass and for the engine to start, if you don't have air at the start spider you most likely have an intermittent start solenoid, which is not all that uncommon. To prove this check to make sure you are in fact delivering air pressure TO the start solenoid. My guess it that you will find that your start solenoid is intermittent. If the problem turns out to be timing I am sure that Dennis can help, if the problem is in the start solenoid I have them for the CJ6 and I do think they just might be the same. Hope this helps. Always Yakin, Doug Sapp -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of Scott Poehlmann Sent: Monday, July 03, 2006 7:58 PM To: yak-list@matronics.com Subject: Yak-List: Yak 55M Air Start Hi All, Have an interesting and troublesome problem. For the last several weeks I have had trouble with the starting the Yak. The scenario is always like this: go out, check the air (650-750 psi), turn the prop through (15 blades), prime, pull the prop through (15 blades), get in, prime, start without any trouble. Go fly acro, mostly working on Advanced-level figures, rollers, inverted spins, half-snaps, with the occaisional run through an Intermediate Known or Free, land, taxi to the pump, fill gas, check the air (again 650-750 psi), get in, prime, hit the starter and nothing happens. I mean NOTHING, no hiss of air, no prop moving, and certainly no start. Rarely I can get the prop to just barely move (less than 1/3 blade), but otherwise nothing. Pulling the prop through in this condition demonstrates that it isn't hydro-locked. My troubleshooting has run like this: 1) There is air in the system. 2) The prop is not hydro-locked. 3) The primer works. 4) The air start valve is clean and in good condition (took it out, cleaned and inspected it last week...). Now I have run out of ideas. Could the air distributor be at fault? If so how, and how do I check it, and how do I sort it out. Ideas? Voodoo spells? Secret Russian code words? I'm up for anything that will work here... Thanks, Scott ________________________________ Message 5 _____________________________________ Time: 07:13:10 AM PST US From: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" Subject: RE: Yak-List: Yak 55M Air Start Scott, make sure you download Rob Kent's pictures, they make great reference material! Yes, I agree... it is much more likely that some foreign object is floating around in the hose, or you have a hose with a "flap" at one end someplace. Taking the lines off and checking for flow will indeed narrow this down. Best of luck, Mark -----Original Message----- [mailto:owner-yak-list-server@matronics.com]On Behalf Of Scott Poehlmann Sent: Wednesday, July 05, 2006 8:39 Hi Mark, Your description of the valve is perfect. That is indeed how the air start on the -55M works. The valve is located on the far lower left of the panel, with a bulkhead below it, and is accessible only through the hole where the floating panel attaches (and around a slightly more than 90 degree corner...), thus must be removed to service in any meaningful way (unless one is a three foot tall, double-jointed elf with extremely long fingers...). I've had this valve out, and apart and can report that the rubbers are correct, with the appropriate holes, and in good condition. As is in the inside of the valve and the spring--very minimal corrosion which came off with just a little bit of cleaning.I am guessing at this point that the problem is hose/line related. The valve connects to a hard line which runs forward to the firewall, and thence to a Russian hose from the firewall to the inlet on the distributor. I will try removing the connector at the firewall and see if I get air there next time I have the problem (I tried to recreate the problem yesterday, but of course, the engine starts perfectly now...). I am hoping at this point that the problem is hose related. I REALLY don't want to futz with the distributor... Thanks, Scott ----- Original Message ----- Point, MALS-14 64E Sent: Wednesday, 05 July, 2006 05:21 Doug, I do not believe that the YAK-55 uses an electrically actuated air start solenoid, such as the 50 and 52 does. Instead I believe it uses the same manually activated valve as do the Sukhoi's. If this is indeed the case, Scott... your most likely cause is corrosion in the air start valve itself OR...and this is a real sneaky problem..... someone in the past has replaced the rubber pad in the air start valve with the wrong one! This problem will drive you NUTS and you have all the symtoms. You really do not have to remove the whole thing to work on it.... although I have never worked on a YAK-55, so I am unsure of the mounting arrangement. If you can get to the back of the thing easily, you can just pull it apart from the rear and leave the main assy. in place. When you take the rear big nut off, you may have to reach into the hole with a tool to get the shuttle to slide out if there is corrosion. Anyway, pulling it that way allows you from having to remove the electrical contacts that activate your voltage booster assy. for the MAGS, which some people refer to as the shower of sparks... which it really isn't. If that is impossible, then simply pull the whole thing out of there and take it apart. Inside you will find a spring... which often breaks from corrosion..... a shuttle valve with ridges on the outside.... clean it and the barrel of the valve carefully.... and on the end of the shuttle you will find that one end is open... hollow, and the other end has a little metal tit sticking out right from the middle. The little metal tit should have a black rubber seal surrounding it. The seal should look like a hard rubber gasket.. not an "O" ring, but instead almost like a thick hard rubber washer. This piece MUST ... and I repeat MUST have a small hole right in the middle of it that allows the metal tit from the shuttle valve itself to stick through it. If you happen to have a hard rubber gasket... round but with no hole in the middle of it... you have found your problem. If it does have a hole in the middle of it... then check for broken weak spring, and/or corrosion in the valve body itself preventing the shuttle from moving freely. Here is how this happens... There is an over-pressure relief valve on most Russian aircraft that works ALMOST exactly like the start valve on your YAK-55. The rubber bushing/seal in it is perfectly round with no hole in the middle and is on the end of a shuttle valve ALMOST but not exactly identical again to the start valve. There is a kit to replace the bushing on the over-pressure relief valve. Many people have mistakenly made the assumption that this same bushing/rubber seal can also replace the one in the start valve. Actually it can.... as long as you carefully put a hole directly in the middle of it so that the metal tit that sticks out from the end of the start valve shuttle can poke through.... otherwise you have symtoms very close to what you are experiencing. It's a long shot... but someone might have done this to your airplane. I have never seen a spider distributor that worked cold, but won't work hot. Those things are devices made by the devil though.... so I guess it is possible! WARNING! Do NOT pull that thing out of your aircraft until you are DARN DARN SURE that it is bad. Expect a few DAYS worth of effort to get it back in and working again. A quick check here would be to simply take the air line off right at the start lever that leads to the engine. Push the start lever. Got plenty of air? No? That pretty much answers your question. Best of Luck, Mark Bitterlich -----Original Message----- [mailto:owner-yak-list-server@matronics.com]On Behalf Of doug sapp Sent: Tuesday, July 04, 2006 12:16 Scott, Have you done this test yet? Next time the problem occurs: Disconnect the hose which runs FROM the start solenoid TO the start spider on the engine, then hit the button and confirm that the start solenoid is functioning and you DO have air at the start spider. If you do have air at the start spider then timing in the start spider has somehow slipped or changed enough to not allow the air to pass and for the engine to start, if you don't have air at the start spider you most likely have an intermittent start solenoid, which is not all that uncommon. To prove this check to make sure you are in fact delivering air pressure TO the start solenoid. My guess it that you will find that your start solenoid is intermittent. If the problem turns out to be timing I am sure that Dennis can help, if the problem is in the start solenoid I have them for the CJ6 and I do think they just might be the same. Hope this helps. Always Yakin, Doug Sapp -----Original Message----- [mailto:owner-yak-list-server@matronics.com]On Behalf Of Scott Poehlmann Sent: Monday, July 03, 2006 7:58 PM Hi All, Have an interesting and troublesome problem. For the last several weeks I have had trouble with the starting the Yak. The scenario is always like this: go out, check the air (650-750 psi), turn the prop through (15 blades), prime, pull the prop through (15 blades), get in, prime, start without any trouble. Go fly acro, mostly working on Advanced-level figures, rollers, inverted spins, half-snaps, with the occaisional run through an Intermediate Known or Free, land, taxi to the pump, fill gas, check the air (again 650-750 psi), get in, prime, hit the starter and nothing happens. I mean NOTHING, no hiss of air, no prop moving, and certainly no start. Rarely I can get the prop to just barely move (less than 1/3 blade), but otherwise nothing. Pulling the prop through in this condition demonstrates that it isn't hydro-locked. My troubleshooting has run like this: 1) There is air in the system. 2) The prop is not hydro-locked. 3) The primer works. 4) The air start valve is clean and in good condition (took it out, cleaned and inspected it last week...). Now I have run out of ideas. Could the air distributor be at fault? If so how, and how do I check it, and how do I sort it out. Ideas? Voodoo spells? Secret Russian code words? I'm up for anything that will work here... Thanks, Scott ________________________________ Message 6 _____________________________________ Time: 07:34:48 AM PST US From: "Richard Goode" Subject: Yak-List: The current Russian military trainer All primary training in Russia is done on the L-39.=0A =0A However the Air Force has ordered, and indeed they are in production, a bat ch of 52M (long-range fuel/bubble canopy/400-hp/3-blade prop/pilot extracti on systems), but none yet delivered.=0A =0A Richard Goode =0A =0A Richard Goode Aerobatics=0A Rhodds Farm=0A Lyonshall=0A Herefordshire=0A HR5 3LW=0A United Kingdom=0A =0A Tel: +44 (0) 1544 340120=0A Mob: +44 (0) 7768 610389=0A Fax: +44 (0) 1544 340129=0A www.russianaeros.com=0A =0A --------------------------------------------------------------------------- --=0A This message has been scanned for viruses and=0A dangerous content by the http://www.invictawiz.com=0A MailScanner, and is believed to be clean.=0A --------------------------------------------------------------------------- --=0A =0A ________________________________ Message 7 _____________________________________ Time: 07:44:38 AM PST US From: cjpilot710@aol.com Subject: Yak-List: Log book Troops, I keep my log book up to date with personal notes about the flight. Who knows, maybe someday my great great grand kids might find them interesting reading while waiting in line for their turn in a molecular transporter to a far off galaxy. One they will read: 2006 July 3 - CJ-6A - N21710 - OLU to OTM = 2.25 hours SEL = 2.25 hours Formation = 2.25 hours PIC = 2.25 hours Remarks #4, CAVOK sct rain showers & CBs. Tolon, WildBill, Lefty. 29gals 7,500' * 500.12 hours of logged formation time. The best guys in the world to kick over a bench mark with. Thanks guys. Pappy ________________________________ Message 8 _____________________________________ Time: 08:43:37 AM PST US From: Buzzard Aviation Subject: Re: Yak-List: The current Russian military trainer Checked by AVG Anti-Virus.