---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Tue 12/31/02: 15 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:08 AM - strut inflation. (Mark Jefferies) 2. 05:07 AM - Re: TCP Use (Craig Payne) 3. 05:33 AM - Re: Fuel tanks (Rob Rowe) 4. 05:45 AM - Re: Fuel tanks (Gus Fraser) 5. 06:29 AM - Re: TCP (Brian Lloyd) 6. 07:24 AM - Re: TCP Use (D Zeman) 7. 08:57 AM - Re: Re: TCP Use (Craig Payne) 8. 09:06 AM - Power output M14 (was TCP) (Gus Fraser) 9. 09:34 AM - Re: Re: Re: TCP Use (D Zeman) 10. 09:48 AM - Re: strut inflation. (Ernie) 11. 09:49 AM - Re: Fuel tanks (Ernie) 12. 09:59 AM - Re: strut inflation. (Ernie) 13. 02:45 PM - Re: Re: Re: Re: TCP Use (Craig Payne) 14. 05:27 PM - Re: Re: Re: Re: Re: TCP Use (D Zeman) 15. 08:31 PM - Re: Timing (Craig Payne) ________________________________ Message 1 _____________________________________ Time: 01:08:34 AM PST US From: "Mark Jefferies" Subject: Yak-List: strut inflation. --> Yak-List message posted by: "Mark Jefferies" Ernie. The special tool for strut inflation is easy to purchase, ask George Coy or order one from us. It screws onto the valve then there is another screw shaft that depresses the inner part of the valve, you then just inflate. All this connects to the standard ground air pipes. If you look at the data plate on the strut it will have the pressure market on it but an easy way is to depress the wing tip and note how hard it travels to full extension again. This valve is used on all FSU a/c, MIG's, L-29. L-39 all YAK's from 3 to 55 I have seen, so should be pretty common amongst maintenance shops. happy new year, mark. Is there any magic to adding gas, is it a special fitting that I'll never find, and do I have to use nitrogen, or can I use air since I don't go o altitudes. Also what pressure should it be charged up to, and what do you guys use as a pressure guage? ________________________________ Message 2 _____________________________________ Time: 05:07:34 AM PST US From: Craig Payne Subject: Re: Yak-List: TCP Use --> Yak-List message posted by: Craig Payne Lead fouling or perhaps oil fouling on the lower plugs? I doubt whether TCP would hurt anything, only using it will prove whether it makes a difference. Then there is the issue of what technique you use to warm up, taxi, and mag check. What sort of plugs are you using? The Champions hold up very well and I have had better luck with the Chinese plugs in the M-14P than the Russian plugs. Craig Payne > --> Yak-List message posted by: D Zeman > > I have had 2 instances of multiple lead plug fouling > with my M14P this winter. I am positive it is due to > the longer fast idle to temp times. > > I am not an additive kind of guy, but I am considering > Alcor's TCP to reduce this sort of thing. Has anyone > had any experience or can comment first hand on the > subject? > > Thanks in advance, > D. Zeman ________________________________ Message 3 _____________________________________ Time: 05:33:47 AM PST US From: "Rob Rowe" Subject: Re: Yak-List: Fuel tanks --> Yak-List message posted by: "Rob Rowe" Hi Ernie, Has a similar fuel imbalance problem a couple of years back whereby the port tank tended to retain more fuel than the starboard tank, over time this got progressively worse until a 30+ litre imbalance could occur within a 50 minute flight - tried all the usual checks but problem persisted. Also checked the underwing tank vents (later YAK 52s have a vent per tank, earlier models had a communal vent) to see if they were equally angled into the slip stream (seems this can cause an air pressure imbalance between tanks impacting fuel flow as well as the flow of excess "return" fuel from the pumping system - the lower pressure tank gets the most fuel). Allegedly this is a common issue on YAK 18s due to their larger capacity tanks and therefore greater endurance which exacerbates the problem - supposedly not so common on standard short range 52s. Anyway - took off one day on full tanks and while climbing away started to smell fuel and noticed a stream emanating from the port wing filler - I landed immediately and checked to find that the circular synthetic fuel cap seal had stretched (probably from repeated over tightening of the cap). Got a replacement and found that this cured both the leak and the imbalance problems ... my speculation is that as the seal progressively stretched it effectively vented the tank to the low pressure on the upper wing surface ultimately causing it to siphon fuel, but in the interim caused the port tank to be at lower pressure than the starboard one and less likely to give up its fuel and/or become the favoured tank for the return of excess fuel. Problem has not re-occurred since - so for what it's worth it may pay you to spend a few dollars on a new fuel cap seal as a quick hit ... I also make sure that I don't over tighten the filler caps now and always do this myself when refuelling. Hope this helps ... Rob Rowe (G-YAKX) ________________________________ Message 4 _____________________________________ Time: 05:45:04 AM PST US From: Gus Fraser Subject: RE: Yak-List: Fuel tanks --> Yak-List message posted by: Gus Fraser Rob, A very useful addition. I had never thought of that as a possibility. I guess the best way to prove if that is the case is to just swap the caps and see if the fault transfers. Gus -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of Rob Rowe Subject: Re: Yak-List: Fuel tanks --> Yak-List message posted by: "Rob Rowe" Hi Ernie, Has a similar fuel imbalance problem a couple of years back whereby the port tank tended to retain more fuel than the starboard tank, over time this got progressively worse until a 30+ litre imbalance could occur within a 50 minute flight - tried all the usual checks but problem persisted. Also checked the underwing tank vents (later YAK 52s have a vent per tank, earlier models had a communal vent) to see if they were equally angled into the slip stream (seems this can cause an air pressure imbalance between tanks impacting fuel flow as well as the flow of excess "return" fuel from the pumping system - the lower pressure tank gets the most fuel). Allegedly this is a common issue on YAK 18s due to their larger capacity tanks and therefore greater endurance which exacerbates the problem - supposedly not so common on standard short range 52s. Anyway - took off one day on full tanks and while climbing away started to smell fuel and noticed a stream emanating from the port wing filler - I landed immediately and checked to find that the circular synthetic fuel cap seal had stretched (probably from repeated over tightening of the cap). Got a replacement and found that this cured both the leak and the imbalance problems ... my speculation is that as the seal progressively stretched it effectively vented the tank to the low pressure on the upper wing surface ultimately causing it to siphon fuel, but in the interim caused the port tank to be at lower pressure than the starboard one and less likely to give up its fuel and/or become the favoured tank for the return of excess fuel. Problem has not re-occurred since - so for what it's worth it may pay you to spend a few dollars on a new fuel cap seal as a quick hit ... I also make sure that I don't over tighten the filler caps now and always do this myself when refuelling. Hope this helps ... Rob Rowe (G-YAKX) ________________________________ Message 5 _____________________________________ Time: 06:29:18 AM PST US From: Brian Lloyd Subject: Re: Yak-List: TCP --> Yak-List message posted by: Brian Lloyd At 12:50 AM 12/31/2002, you wrote: >--> Yak-List message posted by: D Zeman > >I have had 2 instances of multiple lead plug fouling >with my M14P this winter. I am positive it is due to >the longer fast idle to temp times. > >I am not an additive kind of guy, but I am considering >Alcor's TCP to reduce this sort of thing. Has anyone >had any experience or can comment first hand on the >subject? Avgas already has a lead-scavenging agent in it but TCP does help. The only problem is that it works at higher temperatures, not at idle temperatures. I use it religiously in US engines designed for 80/87 to reduce lead fouling (and reduce valve sticking) but it doesn't work well at idle. Brian Lloyd 6501 Red Hook Plaza, Ste 201 brian@lloyd.com St. Thomas, VI 00802 +1.340.998.9447 +1.360.838.9669 ________________________________ Message 6 _____________________________________ Time: 07:24:07 AM PST US From: D Zeman Subject: Yak-List: Re: TCP Use --> Yak-List message posted by: D Zeman Hi Craig, It is a fuel fouling scenario; each time included top plugs (no oil evidence). Last winter it came up after doing power-off and emergency landings (extended times at low power). This winter, it has happened twice. My techniques include slow taxi, but power up from time to time on long taxis. Mag/prop checks at 70% power, but begin and finish each individual check with a 10-15 sec clearing hold at power. Shut-downs at 65% for 45 sec before turning mags off at idle. Do you suggest something different? Thanks for your help, D. ________________________________ Message 7 _____________________________________ Time: 08:57:00 AM PST US From: Craig Payne Subject: Re: Yak-List: Re: TCP Use --> Yak-List message posted by: Craig Payne D. Winter air is rather dense, hence the possibility of an over-rich idle setting setting. Do you know where both your main and idle jets are set? eg: how many clicks rich/lean? I also use an dual EGT guage, one probe on each side as a diagnostic. Helps detect fouled plugs, etc. I mix 100LL fuel with alcohol-free unleaded autogas in a 1:1 ratio. The small farm where I hanger has both so it's easy for me, and we get the benefit of agricultural use prices. Craig Payne > > Hi Craig, > > It is a fuel fouling scenario; each time included top > plugs (no oil evidence). Last winter it came up after > doing power-off and emergency landings (extended times > at low power). This winter, it has happened twice. > > My techniques include slow taxi, but power up from > time to time on long taxis. Mag/prop checks at 70% > power, but begin and finish each individual check with > a 10-15 sec clearing hold at power. Shut-downs at 65% > for 45 sec before turning mags off at idle. Do you > suggest something different? > > Thanks for your help, > D. ==================================================== ________________________________ Message 8 _____________________________________ Time: 09:06:12 AM PST US From: Gus Fraser Subject: Yak-List: Power output M14 (was TCP) --> Yak-List message posted by: Gus Fraser Good thing to do I always hold at 60% for a few seconds just to make sure that the Ts & Ps are OK before doing the 70% checks. From time to time it is possible to get a 5% drop. A 5% drop means losing one plug from the cycle. Often this will clear on departure but if it persists it will need to be looked at. This year I carried out some tests on the static thrust of the M14P the results were interesting and just go to show what a great engine this is. Basically the results were All plugs = 2190 lbs thrust at 100 % One plug removed completely = 2080 lbs @ 100% two plugs removed completely (adjacent cylinders) 900 lbs @100 % I wrote up the details of this test which I have if anyone is interested I can contribute it to all redstar if you want it. Gus -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com]On Behalf Of D Zeman Subject: Yak-List: Re: TCP Use --> Yak-List message posted by: D Zeman Hi Craig, It is a fuel fouling scenario; each time included top plugs (no oil evidence). Last winter it came up after doing power-off and emergency landings (extended times at low power). This winter, it has happened twice. My techniques include slow taxi, but power up from time to time on long taxis. Mag/prop checks at 70% power, but begin and finish each individual check with a 10-15 sec clearing hold at power. Shut-downs at 65% for 45 sec before turning mags off at idle. Do you suggest something different? Thanks for your help, D. ________________________________ Message 9 _____________________________________ Time: 09:34:30 AM PST US From: D Zeman Subject: Yak-List: Re: Re: Re: TCP Use --> Yak-List message posted by: D Zeman Thanks Craig. I have always been tentative about using autofuel. So I am assuming your experience has been good? Do you ever run on straight 100LL? Any noticeable changes? Cheers, D. ________________________________ Message 10 ____________________________________ Time: 09:48:24 AM PST US From: "Ernie" Subject: Re: Yak-List: strut inflation. --> Yak-List message posted by: "Ernie" Have you got a number for George Coy, I'd order one directly from you but shipping from across the pond may be expensive and time consuming. many thanks Ernie ----- Original Message ----- From: "Mark Jefferies" Subject: Yak-List: strut inflation. > --> Yak-List message posted by: "Mark Jefferies" > > Ernie. > > The special tool for strut inflation is easy to purchase, ask George Coy or order one from us. It screws onto the valve then there is another screw shaft that depresses the inner part of the valve, you then just inflate. All this connects to the standard ground air pipes. If you look at the data plate on the strut it will have the pressure market on it but an easy way is to depress the wing tip and note how hard it travels to full extension again. > This valve is used on all FSU a/c, MIG's, L-29. L-39 all YAK's from 3 to 55 I have seen, so should be pretty common amongst maintenance shops. > > happy new year, mark. > > > Is there any magic to adding gas, is it a special fitting that I'll never find, > and do I have to use nitrogen, or can I use air since I don't go o altitudes. > Also what pressure should it be charged up to, and what do you guys use as a pressure > guage? > > ________________________________ Message 11 ____________________________________ Time: 09:49:37 AM PST US From: "Ernie" Subject: Re: Yak-List: Fuel tanks --> Yak-List message posted by: "Ernie" I will swap the caps, I like easy troubleshooting tips like these :) :) Ernie ----- Original Message ----- From: "Gus Fraser" Subject: RE: Yak-List: Fuel tanks > --> Yak-List message posted by: Gus Fraser > > Rob, > A very useful addition. I had never thought of that as a possibility. I > guess the best way to prove if that is the case is to just swap the caps and > see if the fault transfers. > > Gus > > -----Original Message----- > From: owner-yak-list-server@matronics.com > [mailto:owner-yak-list-server@matronics.com]On Behalf Of Rob Rowe > To: yak-list@matronics.com > Subject: Re: Yak-List: Fuel tanks > > > --> Yak-List message posted by: "Rob Rowe" > > Hi Ernie, > Has a similar fuel imbalance problem a couple of years back whereby the port > tank tended to retain more fuel than the starboard tank, over time this got > progressively worse until a 30+ litre imbalance could occur within a 50 > minute flight - tried all the usual checks but problem persisted. > > Also checked the underwing tank vents (later YAK 52s have a vent per tank, > earlier models had a communal vent) to see if they were equally angled into > the slip stream (seems this can cause an air pressure imbalance between > tanks impacting fuel flow as well as the flow of excess "return" fuel from > the pumping system - the lower pressure tank gets the most fuel). Allegedly > this is a common issue on YAK 18s due to their larger capacity tanks and > therefore greater endurance which exacerbates the problem - supposedly not > so common on standard short range 52s. > > Anyway - took off one day on full tanks and while climbing away started to > smell fuel and noticed a stream emanating from the port wing filler - I > landed immediately and checked to find that the circular synthetic fuel cap > seal had stretched (probably from repeated over tightening of the cap). > > Got a replacement and found that this cured both the leak and the imbalance > problems ... my speculation is that as the seal progressively stretched it > effectively vented the tank to the low pressure on the upper wing surface > ultimately causing it to siphon fuel, but in the interim caused the port > tank to be at lower pressure than the starboard one and less likely to give > up its fuel and/or become the favoured tank for the return of excess fuel. > > Problem has not re-occurred since - so for what it's worth it may pay you to > spend a few dollars on a new fuel cap seal as a quick hit ... I also make > sure that I don't over tighten the filler caps now and always do this myself > when refuelling. > > Hope this helps ... > > Rob Rowe (G-YAKX) > > ________________________________ Message 12 ____________________________________ Time: 09:59:47 AM PST US From: "Ernie" Subject: Re: Yak-List: strut inflation. --> Yak-List message posted by: "Ernie" I called George and he doesnt have the original adapter. How much does the adapter cost? If I can afford it I'll take one :) Ernie ----- Original Message ----- From: "Mark Jefferies" Subject: Yak-List: strut inflation. > --> Yak-List message posted by: "Mark Jefferies" > > Ernie. > > The special tool for strut inflation is easy to purchase, ask George Coy or order one from us. It screws onto the valve then there is another screw shaft that depresses the inner part of the valve, you then just inflate. All this connects to the standard ground air pipes. If you look at the data plate on the strut it will have the pressure market on it but an easy way is to depress the wing tip and note how hard it travels to full extension again. > This valve is used on all FSU a/c, MIG's, L-29. L-39 all YAK's from 3 to 55 I have seen, so should be pretty common amongst maintenance shops. > > happy new year, mark. > > > Is there any magic to adding gas, is it a special fitting that I'll never find, > and do I have to use nitrogen, or can I use air since I don't go o altitudes. > Also what pressure should it be charged up to, and what do you guys use as a pressure > guage? > > ________________________________ Message 13 ____________________________________ Time: 02:45:23 PM PST US From: Craig Payne Subject: Re: Yak-List: Re: Re: Re: TCP Use --> Yak-List message posted by: Craig Payne D. Yes I run 100LL when cross country since that's usually all I can get. I haven't run a "straight" M14-P until now with a fresh engine but I'll soon see what results I'll get when I check the plugs. I have been using Chinese plugs and have about 35 hrs on this engine now. My previous M14 was setup with Chinese mags, plugs and ported heads. With 31 degrees full advance, I could pull 900mm MP at sea level. Craig Payne > > Thanks Craig. > > I have always been tentative about using autofuel. So > I am assuming your experience has been good? Do you > ever run on straight 100LL? Any noticeable changes? > > Cheers, > D. ==================================================================== ________________________________ Message 14 ____________________________________ Time: 05:27:59 PM PST US From: D Zeman Subject: Yak-List: Re: Re: Re: Re: Re: TCP Use --> Yak-List message posted by: D Zeman How many Re:'s can we get? ;-) Thanks for the input Craig. I have been religious about getting my engine (straight Russian) into the green before take-off (yellow for run-up). I know some state that our "superior" oil allows pre yellow run-ups and yellow take-offs, but a few more minutes to enjoy my machine doesn't bite me - may be it does during Zima. I think I will be trying some TCP soon. Hopefully by not changing anything else I can make some sort of comparison, although not scientific by any stretch. BTW, although the printed upper limit of timing is 16 deg BTDC on the M14P, do you have a feel for what is an upper limit that is safe for all around operation? Best wishes in the New Year to all! D. ________________________________ Message 15 ____________________________________ Time: 08:31:54 PM PST US From: Craig Payne Subject: Re: Yak-List: Timing --> Yak-List message posted by: Craig Payne No limit to Re's, the same subjects seem to cycle a couple of times of year with each batch of new owners and/or new experiences. Plug fouling seems to be a problem with my Sukhoi friends also. The way they operate their engines differs considerably from what I do. They use the A-B method: 1) Take "A" lever (either throttle or prop) and put it full forward. Then take the Other lever put it full forward and let it "B(e)". As far as mag timing goes, remember that 16 degrees on the prop translates to 23 degrees on the crankshaft (M-14P). I ran mine successfully for about 125 hours at 31 degrees full advance on the crank but only with Chinese mags & spark interrupter that offer considerably less kickback at startup. Happy New Year, time to pop the bubbly take a quick drink and hit the sack while my woman does evening maintenance on her face. Oh well, tomorrow is still just another day. Craig Payne > > How many Re:'s can we get? ;-) > > Thanks for the input Craig. I have been religious > about getting my engine (straight Russian) into the > green before take-off (yellow for run-up). I know > some state that our "superior" oil allows pre yellow > run-ups and yellow take-offs, but a few more minutes > to enjoy my machine doesn't bite me - may be it does > during Zima. > I think I will be trying some TCP soon. Hopefully by > not changing anything else I can make some sort of > comparison, although not scientific by any stretch. > > BTW, although the printed upper limit of timing is 16 > deg BTDC on the M14P, do you have a feel for what is > an upper limit that is safe for all around operation? > > Best wishes in the New Year to all! > D.