The early Dimona leads can be an issue. If they have exposed braid then these can be very old. Inside there can be cracks in this white old silicon and indicates breakdown of wire. Nowadays in Australia you must buy factory leads (once the LAME had the wire on a roll). Aircraft spruce have cables with either aviation plugs or car plugs ready to go for slick 4330. If cables are blue or yellow then indicates a rebuild.
Go to ebay for the adj tool for CD carb. Think it is £12 and leave in plane Recently I made a 20lit mix of ½Avgas and ½car fuel just to check colour of plugs. Easier to sort out tuning quickly. Mine one side were too lean but fit not show up with car fuel. I always use a 4 channel digital CHT and my aim AT SEA LEVEL is stable (not rising) temps of say 175 degC to 180deg c. usually one of the rear cylinders. 190degc and rising is too lean. Inland at altitude it can be a bit too cool so bring throttle back say 1 to 2 cm and up comes the temp to 175deg c. It is my mixture control. Back a bit leans up engine at say 1500ft airport but this can be 3500ft density altitude. I have only used cheap analog EGT and is not very useful. It does give me indication if carb icing is eminent. What height is your home field? Ian McPhee +61 428847642 Box 657 Byron Bay NSW 2481 Australia Ps hope you are not from Trump land as they (abd Burma) still use this funny temp numbers On Sat, 6 Apr 2019 05:47 Jarek Steliga <[email protected]> wrote: > Ric, > > Now I get what you meant I think. I am myself a 'live well alone' type of > person. Thing is that my Limbach doesn't seem to run as smoothly as it > might have. I recently noticed one cylinder becoming considerably hotter > than the others and its plug being black and sooty. Therefore I am trying > to identify the cause. The meetering needle is just one item on the suspect > list, but I am beginning to understand (also from your comments) that this > detail belongs to fine tuning the engine rather than just having it work > decently. > I believe I should focus my snoop on the spark plug cables (the spark > plugs themselves being brand new and professionally rechecked), then on the > magneto. I also take note of the diaphragm holes being a common culprit. > Thank you very much for throwing new light on things. > > > Regards > Jarek > > > > On Wed, 3 Apr 2019 at 22:44, Laurie Hoffman via dog < > [email protected]> wrote: > >> Hi Ric, >> Your comments on the needle adjustment reminded me that over the years we >> have had to adjust them quite a few times. Mainly seasonally. >> >> Rob does an excellent job of maintaining the carbs and motor around those >> key factors you listed and worn butterfly spindles and perforated >> diaphragms come to mind, especially the latter. >> >> For any touring its wise to have a spare set in the 'fly away' kit as >> from our experience diaphragms are the most common part to fail. When >> checking for perforations by holding up to sunlight be very careful not to >> stretch them much as you may well do more harm than good! >> >> And...make sure that the locating lug on the diaphragm goes into its >> correct position on the carby body! >> >> Our Air Experience flights usually involve a climb to between 6000 and >> 7500'. Seasonally, we can notice poor running and loss of power as we >> approach these levels due to over rich running as confirmed by exhaust and >> plug colour. >> >> As Rob mentioned, usually 1/4-1/2 turn does the trick. >> Laurie >> Sent from Yahoo7 Mail on Android >> <https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub2=Global_YGrowth&af_sub3=EmailSignature> >> >> On Thu, 4 Apr 2019 at 12:43 am, Ric Sutton >> <[email protected]> wrote: >> >> Hi Jarek >> >> While i do have some mechanical qualifications, please remember that what >> i say should by no means be taken as a rule or the final word. i am just as >> fallible as the next person. >> >> i am always happy to hear about information like you have presented here >> because in most cases it adds to my body of knowledge. >> >> Even if i find information of a dubious nature it may help me understand >> how or why people do things. >> >> If you get the impression that altering the main jet(needle) adjustment >> will improve the way your machine runs then absolutely get stuck into it >> and tell us what you found. Particularly if it means a few more horses to >> yank our birds aloft on a hot summers day. >> >> >> >> While mine sounds as sweet as a steel box full of chooks, wild cats, jack >> hammers and several crates of empty beer bottles rolling down a mountain, >> i probably aint gunna mess with it till something changes. (kidding- it >> runs a little better than that- replace “wild cats” with “highly excitable >> domestic cats”). >> >> >> >> Though, if it does change i would look for other causes like diaphragm >> holes, worn butterfly spindles, needle and seat not doing their job, >> blocked fuel/air filters, loose manifold/carb mounting bolts blah blah blah >> etc etc. >> >> i guess things wear and change but hopefully not too much. >> >> >> >> Out of interest, how often were you thinking of doing this? >> >> >> >> Fair weather >> >> ric >> >> >> >> *From:* [email protected] [mailto:[email protected]] *On >> Behalf Of *Jarek Steliga >> *Sent:* Tuesday, 2 April 2019 2:53 AM >> *To:* [email protected] >> *Subject:* Re: [DOG mailing list] Zenith 150 C3 meetering needle >> adjustment >> >> >> >> Rob, Ric, >> >> >> >> Thank you. I am going to follow your advice shortly. >> >> >> >> Ric, >> >> >> >> Your question 'why I want to do this' baffled me. I watched the attached >> video, I read some sections in the Zenith user's manual and inferred that >> the adjustment is a must. >> >> Do you think it's redundant or excessive? As for the vacuum gauges, I >> procured them even before reading your comments here and yes I will be very >> mindful of the man mincer :-). >> >> >> >> Best regards to both of you >> >> >> >> Jarek >> >> >> >> >> >> >> >> On Mon, 1 Apr 2019 at 15:52, Ric Sutton <[email protected]> wrote: >> >> Hi Jarek >> >> For my two cents, i guess my question would be why you want to do this. >> But onwards and further to robs comments i check my throttle opening with >> vacuum gauges plugged into the balance pipe ports on the intake manifold. >> Yes the engine needs to be running but i sit in the cockpit- much safer >> than standing next to that spinning man mincer. The vacuum needs to be the >> same at idle and at wide open throttle and by the same i mean having >> identical readings between carbs not identical readings at idle and at full >> throttle...... eh you know what i mean. >> >> Good luck >> >> ric >> >> >> >> *From:* [email protected] [mailto:[email protected]] *On >> Behalf Of *Jarek Steliga >> *Sent:* Monday, 1 April 2019 4:18 AM >> *To:* [email protected] >> *Subject:* [DOG mailing list] Zenith 150 C3 meetering needle adjustment >> >> >> >> >> >> >> >> Hello everyone, >> >> >> >> I watched this video https://www.youtube.com/watch?v=wenBlytGjSI but is >> it of any use in the case of TWO carburators as is on my Limbach 2000? Is >> the meetering needle adjustment at all possible in this case? How should I >> go about it? >> >> >> >> >> >> Thank you in anticipation >> >> >> >> Regards >> >> Jarek >> >> >> >> >> >>
