---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Fri 04/28/06: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:18 AM - excessive mag drop & warm cyl. (Bill Walker) 2. 05:43 AM - Re: excessive mag drop & warm cyl. (A. Dennis Savarese) 3. 06:19 AM - Re: excessive mag drop & warm cyl. (Bill Walker) 4. 07:56 AM - Re: importing (Hank Gibson) 5. 09:35 AM - Re: excessive mag drop & warm cyl. (Jim Bernier) 6. 09:49 AM - CJ Service Techs in USA (Hank Gibson) 7. 09:58 AM - Re: CJ Service Techs in USA (Jim Bernier) 8. 01:17 PM - Re: excessive mag drop & warm cyl. (Bitterlich GS11 Mark G) 9. 01:29 PM - Re: Re: excessive mag drop & warm cyl. (Craig Payne) 10. 01:48 PM - Re: Re: Re: excessive mag drop & warm cyl. (doug sapp) 11. 04:58 PM - mag drop and warm cyl (Bill Walker) 12. 06:26 PM - Re: excessive mag drop & warm cyl. (Roger Kemp) 13. 08:27 PM - Re: CJ Service Techs in USA (ByronMFox@aol.com) 14. 10:41 PM - Mig-15 paper airplane (Sarah Tobin) ________________________________ Message 1 _____________________________________ Time: 05:18:39 AM PST US From: "Bill Walker" Subject: Yak-List: excessive mag drop & warm cyl. Last July just before OSH I got water in the ignition wires on my regular 52. After various methods of drying out the wires, I ended up fouling the champions, so I replaced them with the Chinese plugs. ran well with good mag checks but I immediately noticed a little higher cylinder head temps at various power settings. After a few months, I began to experience mag checks in excess of 3 percent. mag checks degraded to 5 or 6 percent drop on both mags but the engine ran smooth. I changed out the ignition harness and plugs with the kit from Dennis, checked timing, point gaps, and plug gaps. The engine starts easy, runs smooth, and develops 100 percent RPM, but I still get a 5 percent mag drop during a static run up whether before or after a flight, and cylinder head temps are still 10 to 20 degrees higher than normal during all phases of operation. Also compression checked over 70/80 on all cylinders. I have not measured the valve clearances lately, I suppose I could have an exhaust valve not opening completely. Any Ideas, anyone ? Dennis? Wild Bill ________________________________ Message 2 _____________________________________ Time: 05:43:14 AM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: excessive mag drop & warm cyl. Bill, Just a couple of questions first - -What did you use to set TDC when you checked/set the timing? -What did you set the timing to? The spec is 14-16 degrees BTDC as measured at the propeller flange. -When you found what degree the points opened with the mag timing box, did you check to see if the rotor was pointing DIRECTLY at the scribed mark on the mag boss? - When was the last time the mag caps/distribution caps were replaced? The condition of the contacts on both the rotor and cap can make a difference. - Have you tried swapping the mags from left to right to see if the 5% mag drop follows the mag swap? - Has anyone made any fuel flow adjustments on the carburetor? - Are you certain you do not have any intake leaks particularly around the intake gland nuts and their rubber seals which could cause lean operation and higher CHT's? Dennis ----- Original Message ----- From: Bill Walker To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:15 AM Subject: Yak-List: excessive mag drop & warm cyl. Last July just before OSH I got water in the ignition wires on my regular 52. After various methods of drying out the wires, I ended up fouling the champions, so I replaced them with the Chinese plugs. ran well with good mag checks but I immediately noticed a little higher cylinder head temps at various power settings. After a few months, I began to experience mag checks in excess of 3 percent. mag checks degraded to 5 or 6 percent drop on both mags but the engine ran smooth. I changed out the ignition harness and plugs with the kit from Dennis, checked timing, point gaps, and plug gaps. The engine starts easy, runs smooth, and develops 100 percent RPM, but I still get a 5 percent mag drop during a static run up whether before or after a flight, and cylinder head temps are still 10 to 20 degrees higher than normal during all phases of operation. Also compression checked over 70/80 on all cylinders. I have not measured the valve clearances lately, I suppose I could have an exhaust valve not opening completely. Any Ideas, anyone ? Dennis? Wild Bill ________________________________ Message 3 _____________________________________ Time: 06:19:12 AM PST US From: "Bill Walker" Subject: Re: Yak-List: excessive mag drop & warm cyl. ----- Original Message ----- From: A. Dennis Savarese To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:42 AM Subject: Re: Yak-List: excessive mag drop & warm cyl. Bill, Just a couple of questions first - -What did you use to set TDC when you checked/set the timing? I watched the exhaust valve open and close during the exhaust stroke to make sure I was on the compression stroke and used a screwdriver to feel for TDC on the top of the piston. -What did you set the timing to? The spec is 14-16 degrees BTDC as measured at the propeller flange. After marking "0" with a piece of saftey wire, I backed up the to 30 BTDC then pulled in the direction of rotation. Both lights came on at the same time at 15 BTDC. -When you found what degree the points opened with the mag timing box, did you check to see if the rotor was pointing DIRECTLY at the scribed mark on the mag boss? Did not check this - I'll go back and do it. - When was the last time the mag caps/distribution caps were replaced? The condition of the contacts on both the rotor and cap can make a difference. I swapped a mag cap off my new plane on one of the mags and It did not make any difference on either plane. Mag caps looked good anyway. - Have you tried swapping the mags from left to right to see if the 5% mag drop follows the mag swap? No, both mags are getting equal drop. Except for watching the RPM for each mag, I could not tell it there was anything wrong. - Has anyone made any fuel flow adjustments on the carburetor? No - Are you certain you do not have any intake leaks particularly around the intake gland nuts and their rubber seals which could cause lean operation and higher CHT's? Good Idea - I'm going to check these today along with the valve clearances. Dennis Thanks, Dennis Wild Bill ----- Original Message ----- From: Bill Walker To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:15 AM Subject: Yak-List: excessive mag drop & warm cyl. Last July just before OSH I got water in the ignition wires on my regular 52. After various methods of drying out the wires, I ended up fouling the champions, so I replaced them with the Chinese plugs. ran well with good mag checks but I immediately noticed a little higher cylinder head temps at various power settings. After a few months, I began to experience mag checks in excess of 3 percent. mag checks degraded to 5 or 6 percent drop on both mags but the engine ran smooth. I changed out the ignition harness and plugs with the kit from Dennis, checked timing, point gaps, and plug gaps. The engine starts easy, runs smooth, and develops 100 percent RPM, but I still get a 5 percent mag drop during a static run up whether before or after a flight, and cylinder head temps are still 10 to 20 degrees higher than normal during all phases of operation. Also compression checked over 70/80 on all cylinders. I have not measured the valve clearances lately, I suppose I could have an exhaust valve not opening completely. Any Ideas, anyone ? Dennis? Wild Bill ________________________________ Message 4 _____________________________________ Time: 07:56:50 AM PST US From: Hank Gibson Subject: Re: Yak-List: importing Anthony, Start with the following sites for info and pics with Aussie and Kiwi registrations: www.lampa.com.au , www.thinkingskills.co.za , http://www.jetphotos.net/showphotos.php?offset=0&where=search|-2|-2|-2|-2|CJ-6|15|1|||||||-2|-2|-2|-2|||15|1||-2|-2||||all|2||||||-2|||1 . Good luck! Anthony Hudacek wrote: I am new to this list and am thinking of importing a yak from russia to Australia. If anybody else is interested we could bring back a couple and cost share the freight etc. If interested send me an email on antdea2000@yahoo.com.au. Has anyone else imported aircraft into Australia? Thanks, Ant. --------------------------------- Hank Gibson 904-994-6005 Mobile 904-213-1760 Home hkgibby@yahoo.com --------------------------------- ________________________________ Message 5 _____________________________________ Time: 09:35:12 AM PST US From: "Jim Bernier" Subject: Re: Yak-List: excessive mag drop & warm cyl. --> Yak-List message posted by: "Jim Bernier" Bill I found it far more accurate to find TDC by making a tool out of an old spark plug. Hollow out the ceramic center, all of the ceramic, and force a steel rod down the center so that it extends beyond the point were the piston would miss it. You determine this distance with the same screw driver. Measure the distance that the screw driver travels into the cylinder at the same angle as the plug would travel when the piston is near TDC. Add about 0.5 inches to the distance. Affix the rod to this distance in the plug by measuring from the flat contact point. You should round the end of the rod so it doesn't nick the piston. I used JB Weld to hold it in place. Be certain that when you rotate the plug that the rod stays centered. Pull the piston back down by reversing the prop direction, counter clockwise. Insert the new plug and finger tighten. Bring the piston back up in contact with the plug. Slowly. Once this is established read the degrees on the prop hub with a digital level. (They cost about $100 on the internet and well worth it.) Find the angle on the opposite side of the piston travel. Same technique, only with the piston traveling in the opposite direction. You will have to remove the plug, bring the piston beyond TDC, replace the plug, bring the piston back toward TDC until it touches the plug. Measure this angle using the same place on the prop hub. Determine the difference and divide it by 2. Add this to the original measurement for an accurate TDC. To find the advanced angle that the mags need to be set at just add this to your calculated TDC angle. Always set the piston in this position by moving the prop from well before TDC to the determined angle, prop turning in normal rotation. Clockwise as you face it. It's more work but very accurate. BTW, As long as you set the final prop angle by moving it clockwise, prop lash will not be a factor. If you move it counter clockwise it will be a factor and your final piston position will be wrong. Good luck. Jim B >>> bwalker11@charter.net 04/28/06 8:18 AM >>> ----- Original Message ----- From: A. Dennis Savarese To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:42 AM Subject: Re: Yak-List: excessive mag drop & warm cyl. Bill, Just a couple of questions first - -What did you use to set TDC when you checked/set the timing? I watched the exhaust valve open and close during the exhaust stroke to make sure I was on the compression stroke and used a screwdriver to feel for TDC on the top of the piston. -What did you set the timing to? The spec is 14-16 degrees BTDC as measured at the propeller flange. After marking "0" with a piece of saftey wire, I backed up the to 30 BTDC then pulled in the direction of rotation. Both lights came on at the same time at 15 BTDC. -When you found what degree the points opened with the mag timing box, did you check to see if the rotor was pointing DIRECTLY at the scribed mark on the mag boss? Did not check this - I'll go back and do it. - When was the last time the mag caps/distribution caps were replaced? The condition of the contacts on both the rotor and cap can make a difference. I swapped a mag cap off my new plane on one of the mags and It did not make any difference on either plane. Mag caps looked good anyway. - Have you tried swapping the mags from left to right to see if the 5% mag drop follows the mag swap? No, both mags are getting equal drop. Except for watching the RPM for each mag, I could not tell it there was anything wrong. - Has anyone made any fuel flow adjustments on the carburetor? No - Are you certain you do not have any intake leaks particularly around the intake gland nuts and their rubber seals which could cause lean operation and higher CHT's? Good Idea - I'm going to check these today along with the valve clearances. Dennis Thanks, Dennis Wild Bill ----- Original Message ----- From: Bill Walker To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:15 AM Subject: Yak-List: excessive mag drop & warm cyl. Last July just before OSH I got water in the ignition wires on my regular 52. After various methods of drying out the wires, I ended up fouling the champions, so I replaced them with the Chinese plugs. ran well with good mag checks but I immediately noticed a little higher cylinder head temps at various power settings. After a few months, I began to experience mag checks in excess of 3 percent. mag checks degraded to 5 or 6 percent drop on both mags but the engine ran smooth. I changed out the ignition harness and plugs with the kit from Dennis, checked timing, point gaps, and plug gaps. The engine starts easy, runs smooth, and develops 100 percent RPM, but I still get a 5 percent mag drop during a static run up whether before or after a flight, and cylinder head temps are still 10 to 20 degrees higher than normal during all phases of operation. Also compression checked over 70/80 on all cylinders. I have not measured the valve clearances lately, I suppose I could have an exhaust valve not opening completely. Any Ideas, anyone ? Dennis? Wild Bill ________________________________ Message 6 _____________________________________ Time: 09:49:31 AM PST US From: Hank Gibson Subject: Yak-List: CJ Service Techs in USA Hello, I am buying a CJ6 and am putting together a list of A&P's and Avionics techs who people have had sucess with from around the lower 48 and Canada. Any and all input with names and contact details would be appreciated. You never know when and where you'll break. Thanks, Hank Gibson Hank Gibson 904-994-6005 Mobile 904-213-1760 Home hkgibby@yahoo.com --------------------------------- ________________________________ Message 7 _____________________________________ Time: 09:58:11 AM PST US From: "Jim Bernier" Subject: Re: Yak-List: CJ Service Techs in USA --> Yak-List message posted by: "Jim Bernier" My FSDO rep told me to keep the manuals on a CD and place it in the plane. That way were ever you break down you can have an A&P work on it. The only thing that prohibits work is knowledge. Jim B. >>> hkgibby@yahoo.com 04/28/06 11:48 AM >>> Hello, I am buying a CJ6 and am putting together a list of A&P's and Avionics techs who people have had sucess with from around the lower 48 and Canada. Any and all input with names and contact details would be appreciated. You never know when and where you'll break. Thanks, Hank Gibson Hank Gibson 904-994-6005 Mobile 904-213-1760 Home hkgibby@yahoo.com --------------------------------- ________________________________ Message 8 _____________________________________ Time: 01:17:08 PM PST US From: Bitterlich GS11 Mark G Subject: RE: Yak-List: excessive mag drop & warm cyl. The suggestions for finding TDC and setting timing accurately have already been given and are very good obviously. What I believe is significant is that both Mags have equal drop, and as they drop increased, they stayed equal through-out the process. One thing I can say from direct observation and that is, the more advanced the engine timing is, the less the mag drop, and... a retarded engine runs hot. Just the opposite of what makes sense. So... maybe it IS timing. Valve Lash. There is just no question that valve lash drifts considerably in one year. In other words, I strongly suspect you have a valve lash issue simply by the statement that you have not adjusted them in awhile. What is "awhile" ?? I run my engine very hard, and have gotten into the habit of checking them every 6 months or so. I've also seen a dramatic change in valve lash going from hot to cold. Opinions vary on how to set lash... most people say: "Medium Warm". I'd like to hear what Dennis has to say about that personally. I have measured lash when the engine is HOT HOT HOT... and then have let it go stone cold and have measured it again. I was agog.... it is a HUGE difference. Since lash can impact generated power by a LOT... I lean towards setting them HOT. Of course, it is then hard to set them all the same! Setting them dead cold at least gets them all the same... assuming the change with heat is linear on all cylinders. What do you have to say about this Dennis, or anyone else for that matter? Mark N50YK -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of Jim Bernier Sent: Friday, April 28, 2006 12:33 PM Subject: Re: Yak-List: excessive mag drop & warm cyl. --> Yak-List message posted by: "Jim Bernier" Bill I found it far more accurate to find TDC by making a tool out of an old spark plug. Hollow out the ceramic center, all of the ceramic, and force a steel rod down the center so that it extends beyond the point were the piston would miss it. You determine this distance with the same screw driver. Measure the distance that the screw driver travels into the cylinder at the same angle as the plug would travel when the piston is near TDC. Add about 0.5 inches to the distance. Affix the rod to this distance in the plug by measuring from the flat contact point. You should round the end of the rod so it doesn't nick the piston. I used JB Weld to hold it in place. Be certain that when you rotate the plug that the rod stays centered. Pull the piston back down by reversing the prop direction, counter clockwise. Insert the new plug and finger tighten. Bring the piston back up in contact with the plug. Slowly. Once this is established read the degrees on the prop hub with a digital level! . (They cost about $100 on the internet and well worth it.) Find the angle on the opposite side of the piston travel. Same technique, only with the piston traveling in the opposite direction. You will have to remove the plug, bring the piston beyond TDC, replace the plug, bring the piston back toward TDC until it touches the plug. Measure this angle using the same place on the prop hub. Determine the difference and divide it by 2. Add this to the original measurement for an accurate TDC. To find the advanced angle that the mags need to be set at just add this to your calculated TDC angle. Always set the piston in this position by moving the prop from well before TDC to the determined angle, prop turning in normal rotation. Clockwise as you face it. It's more work but very accurate. BTW, As long as you set the final prop angle by moving it clockwise, prop lash will not be a factor. If you move it counter clockwise it will be a factor and your final piston position will be wrong. Good luck. Jim B >>> bwalker11@charter.net 04/28/06 8:18 AM >>> ----- Original Message ----- From: A. Dennis Savarese To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:42 AM Subject: Re: Yak-List: excessive mag drop & warm cyl. Bill, Just a couple of questions first - -What did you use to set TDC when you checked/set the timing? I watched the exhaust valve open and close during the exhaust stroke to make sure I was on the compression stroke and used a screwdriver to feel for TDC on the top of the piston. -What did you set the timing to? The spec is 14-16 degrees BTDC as measured at the propeller flange. After marking "0" with a piece of saftey wire, I backed up the to 30 BTDC then pulled in the direction of rotation. Both lights came on at the same time at 15 BTDC. -When you found what degree the points opened with the mag timing box, did you check to see if the rotor was pointing DIRECTLY at the scribed mark on the mag boss? Did not check this - I'll go back and do it. - When was the last time the mag caps/distribution caps were replaced? The condition of the contacts on both the rotor and cap can make a difference. I swapped a mag cap off my new plane on one of the mags and It did not make any difference on either plane. Mag caps looked good anyway. - Have you tried swapping the mags from left to right to see if the 5% mag drop follows the mag swap? No, both mags are getting equal drop. Except for watching the RPM for each mag, I could not tell it there was anything wrong. - Has anyone made any fuel flow adjustments on the carburetor? No - Are you certain you do not have any intake leaks particularly around the intake gland nuts and their rubber seals which could cause lean operation and higher CHT's? Good Idea - I'm going to check these today along with the valve clearances. Dennis Thanks, Dennis Wild Bill ----- Original Message ----- From: Bill Walker To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:15 AM Subject: Yak-List: excessive mag drop & warm cyl. Last July just before OSH I got water in the ignition wires on my regular 52. After various methods of drying out the wires, I ended up fouling the champions, so I replaced them with the Chinese plugs. ran well with good mag checks but I immediately noticed a little higher cylinder head temps at various power settings. After a few months, I began to experience mag checks in excess of 3 percent. mag checks degraded to 5 or 6 percent drop on both mags but the engine ran smooth. I changed out the ignition harness and plugs with the kit from Dennis, checked timing, point gaps, and plug gaps. The engine starts easy, runs smooth, and develops 100 percent RPM, but I still get a 5 percent mag drop during a static run up whether before or after a flight, and cylinder head temps are still 10 to 20 degrees higher than normal during all phases of operation. Also compression checked over 70/80 on all cylinders. I have not measured the valve clearances lately, I suppose I could ! have an exhaust valve not opening completely. Any Ideas, anyone ? Dennis? Wild Bill ________________________________ Message 9 _____________________________________ Time: 01:29:16 PM PST US From: "Craig Payne" Subject: Yak-List: Re: Re: excessive mag drop & warm cyl. >Bill >I found it far more accurate to find TDC by making a tool out of an old spark plug. > > Arrggg! You guys need to do it right! Either use a 14MM American Time-Rite or the calibrated Russian built dial indicator. Measure *exact* degrees directly off the crank on #4 and set your mags using a "buzz box" synchronizer, with lights of course. Set a 6" rule across the rotor when lining up the firing lead....or use a laser line like I do. A couple hundred bucks spent on the right tools will more than be compensated with a smooth running engine. Or, find someone with the tools and knowledge to do it for you. Craig Payne Obsessive-Complusive Tuner (OCT) ________________________________ Message 10 ____________________________________ Time: 01:48:10 PM PST US From: "doug sapp" Subject: RE: Yak-List: Re: Re: excessive mag drop & warm cyl. There have been several NIB Time Rites on Ebay lately. I bought one @ 285.00, great value as they are over $400.00 new. There is one or two of them offered at this time. Always Yakin, Doug Sapp -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of Craig Payne Sent: Friday, April 28, 2006 1:29 PM To: yak-list Subject: Yak-List: Re: Re: excessive mag drop & warm cyl. >Bill >I found it far more accurate to find TDC by making a tool out of an old spark plug. > > Arrggg! You guys need to do it right! Either use a 14MM American Time-Rite or the calibrated Russian built dial indicator. Measure *exact* degrees directly off the crank on #4 and set your mags using a "buzz box" synchronizer, with lights of course. Set a 6" rule across the rotor when lining up the firing lead....or use a laser line like I do. A couple hundred bucks spent on the right tools will more than be compensated with a smooth running engine. Or, find someone with the tools and knowledge to do it for you. Craig Payne Obsessive-Complusive Tuner (OCT) ________________________________ Message 11 ____________________________________ Time: 04:58:05 PM PST US From: "Bill Walker" Subject: Yak-List: mag drop and warm cyl Thanks, Mark, Jim, Craig, Doug, & Dennis. I'm going back to the drawing board and check the timming more accurately as well as checking the other things mentioned. Some good ideas for doing it right! Wild Bill ________________________________ Message 12 ____________________________________ Time: 06:26:14 PM PST US From: "Roger Kemp" Subject: RE: Yak-List: excessive mag drop & warm cyl. Makes since to measure the valve lash warm to hot. The engine actually expands with heat. If you measure the circumference of the engine around the baffle pads or even over the valve covers when it is cold and then when it is hot, you will find it has increased in size by 2 inches. If you do not believe me talk to the Kimball's at Kimball's enterprises. They found that out doing custom cowlings for there aircraft that used the M-14. Doc ----- Original Message ----- From: Bitterlich GS11 Mark G Sent: 4/28/2006 3:25:01 PM Subject: RE: Yak-List: excessive mag drop & warm cyl. The suggestions for finding TDC and setting timing accurately have already been given and are very good obviously. What I believe is significant is that both Mags have equal drop, and as they drop increased, they stayed equal through-out the process. One thing I can say from direct observation and that is, the more advanced the engine timing is, the less the mag drop, and... a retarded engine runs hot. Just the opposite of what makes sense. So... maybe it IS timing. Valve Lash. There is just no question that valve lash drifts considerably in one year. In other words, I strongly suspect you have a valve lash issue simply by the statement that you have not adjusted them in awhile. What is "awhile" ?? I run my engine very hard, and have gotten into the habit of checking them every 6 months or so. I've also seen a dramatic change in valve lash going from hot to cold. Opinions vary on how to set lash... most people say: "Medium Warm". I'd like to hear what Dennis has to say about that personally. I have measured lash when the engine is HOT HOT HOT... and then have let it go stone cold and have measured it again. I was agog.... it is a HUGE difference. Since lash can impact generated power by a LOT... I lean towards setting them HOT. Of course, it is then hard to set them all the same! Setting them dead cold at least gets them all the same... assuming the change with heat is linear on all cylinders. What do you have to say about this Dennis, or anyone else for that matter? Mark N50YK -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of Jim Bernier Sent: Friday, April 28, 2006 12:33 PM Subject: Re: Yak-List: excessive mag drop & warm cyl. --> Yak-List message posted by: "Jim Bernier" Bill I found it far more accurate to find TDC by making a tool out of an old spark plug. Hollow out the ceramic center, all of the ceramic, and force a steel rod down the center so that it extends beyond the point were the piston would miss it. You determine this distance with the same screw driver. Measure the distance that the screw driver travels into the cylinder at the same angle as the plug would travel when the piston is near TDC. Add about 0.5 inches to the distance. Affix the rod to this distance in the plug by measuring from the flat contact point. You should round the end of the rod so it doesn't nick the piston. I used JB Weld to hold it in place. Be certain that when you rotate the plug that the rod stays centered. Pull the piston back down by reversing the prop direction, counter clockwise. Insert the new plug and finger tighten. Bring the piston back up in contact with the plug. Slowly. Once this is established read the degrees on the prop hub with a digital level! . (They cost about $100 on the internet and well worth it.) Find the angle on the opposite side of the piston travel. Same technique, only with the piston traveling in the opposite direction. You will have to remove the plug, bring the piston beyond TDC, replace the plug, bring the piston back toward TDC until it touches the plug. Measure this angle using the same place on the prop hub. Determine the difference and divide it by 2. Add this to the original measurement for an accurate TDC. To find the advanced angle that the mags need to be set at just add this to your calculated TDC angle. Always set the piston in this position by moving the prop from well before TDC to the determined angle, prop turning in normal rotation. Clockwise as you face it. It's more work but very accurate. BTW, As long as you set the final prop angle by moving it clockwise, prop lash will not be a factor. If you move it counter clockwise it will be a factor and your final piston position will be wrong. Good luck. Jim B >>> bwalker11@charter.net 04/28/06 8:18 AM >>> ----- Original Message ----- From: A. Dennis Savarese To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:42 AM Subject: Re: Yak-List: excessive mag drop & warm cyl. Bill, Just a couple of questions first - -What did you use to set TDC when you checked/set the timing? I watched the exhaust valve open and close during the exhaust stroke to make sure I was on the compression stroke and used a screwdriver to feel for TDC on the top of the piston. -What did you set the timing to? The spec is 14-16 degrees BTDC as measured at the propeller flange. After marking "0" with a piece of saftey wire, I backed up the to 30 BTDC then pulled in the direction of rotation. Both lights came on at the same time at 15 BTDC. -When you found what degree the points opened with the mag timing box, did you check to see if the rotor was pointing DIRECTLY at the scribed mark on the mag boss? Did not check this - I'll go back and do it. - When was the last time the mag caps/distribution caps were replaced? The condition of the contacts on both the rotor and cap can make a difference. I swapped a mag cap off my new plane on one of the mags and It did not make any difference on either plane. Mag caps looked good anyway. - Have you tried swapping the mags from left to right to see if the 5% mag drop follows the mag swap? No, both mags are getting equal drop. Except for watching the RPM for each mag, I could not tell it there was anything wrong. - Has anyone made any fuel flow adjustments on the carburetor? No - Are you certain you do not have any intake leaks particularly around the intake gland nuts and their rubber seals which could cause lean operation and higher CHT's? Good Idea - I'm going to check these today along with the valve clearances. Dennis Thanks, Dennis Wild Bill ----- Original Message ----- From: Bill Walker To: yak-list@matronics.com Sent: Friday, April 28, 2006 7:15 AM Subject: Yak-List: excessive mag drop & warm cyl. Last July just before OSH I got water in the ignition wires on my regular 52. After various methods of drying out the wires, I ended up fouling the champions, so I replaced them with the Chinese plugs. ran well with good mag checks but I immediately noticed a little higher cylinder head temps at various power settings. After a few months, I began to experience mag checks in excess of 3 percent. mag checks degraded to 5 or 6 percent drop on both mags but the engine ran smooth. I changed out the ignition harness and plugs with the kit from Dennis, checked timing, point gaps, and plug gaps. The engine starts easy, runs smooth, and develops 100 percent RPM, but I still get a 5 percent mag drop during a static run up whether before or after a flight, and cylinder head temps are still 10 to 20 degrees higher than normal during all phases of operation. Also compression checked over 70/80 on all cylinders. I have not measured the valve clearances lately, I suppose I could ! have an exhaust valve not opening completely. Any Ideas, anyone ? Dennis? Wild Bill browse Subscriptions page, Chat, FAQ, HREF="http://www.matronics.com/Navigator?Yak-List" TARGET="_blank">http://www.matronics.com/Navigator?Yak-List Wiki! TARGET="_blank">http://wiki.matronics.com support! HREF="http://www.matronics.com/contribution" TARGET="_blank">http://www.matronics.com/contribution ________________________________ Message 13 ____________________________________ Time: 08:27:36 PM PST US From: ByronMFox@aol.com Subject: Re: Yak-List: CJ Service Techs in USA In a message dated 4/28/2006 9:50:30 AM Pacific Standard Time, hkgibby@yahoo.com writes: I am buying a CJ6 and am putting together a list of A&P's and Avionics techs who people have had success with from around the lower 48 and Canada. In the San Francisco Bay Area, Jim Selby at Marina Airport (OAR) near Monterey has extensive CJ experience. I think Jim has imported north of 20 CJs. He expertly maintains most of the CJs in our area. Jim can be reached at 831-883-1266 and at jimscjs@mbay.net ...Blitz Byron M. Fox 80 Milland Drive Mill Valley, CA 94941 Home 415-380-0907 Cell 415-307-2405 ________________________________ Message 14 ____________________________________ Time: 10:41:28 PM PST US From: Sarah Tobin Subject: Yak-List: Mig-15 paper airplane http://www.paperparadise.com/free/mig15.cfm This sounds like fun and it free to download, I guess if you like it, you can pay for other downloads. I just don't have that much free time, but hey....enjoy Smash --------------------------------- ---------------------------------