Hi Rob, No, I have made no adjustments to the propeller pitch. Yes, I have done the compression test and it gave good and consistent results on all 4 cylinders.
Regards Jarek On Sun, 5 Jan 2020 at 00:36, Rob Thompson <[email protected]> wrote: > Hi Jarek, > Have you made any adjustments to the propeller pitch whilst you have been > having these problems? > Also have you done a compression test? > regards > Rob > > Rob Thompson > 0429 493 828 > (Please note that my new email address is [email protected]) > > > On Sun, Jan 5, 2020 at 8:48 AM Jarek Steliga <[email protected]> > wrote: > >> Hi Ian, >> >> I have just stumbled upon this article >> https://www.aopa.org/news-and-media/all-news/2005/august/pilot/soar-like-a-sea-gull >> where >> I found the following statement: " Acceleration is satisfying, >> especially after you discover that the engine, which nominally produces 80 >> horsepower at 3,400 rpm, only puts out 50 horsepower or so in the >> 2,500-to-2,800-rpm actual operating range." >> >> This made me think again if perhaps my Dimona is flyable after all even >> if it clearly falls short of your benchmarks. The fact is that prior to the >> recent replacement of the throttle shafts and butterflies, the engine used >> to rev up to 2700 static, but it was pretty erratic and uneven and I >> remember distinctly I could hold the plane in place with just the use of >> the handbrake (no choks), while now I need the chocks even if the max RPM >> are just 2500. >> >> I wonder if you would find time and interest to have a look at this >> article. >> >> Best regards >> Jarek >> >> P.S. I discovered with some satisfaction that you have some Polish made >> (or at least) designed gliders like PW5, Cobra and Puchatek in your fleet. >> >> >> >> >> On Fri, 3 Jan 2020 at 21:58, Jarek Steliga <[email protected]> >> wrote: >> >>> Hello Ian, >>> >>> Thank you again. I know enough. There's nothing for it but to roll up my >>> sleeves and find the reason for this slow rotation rate of my machine along >>> the suggestions made by yourself and other people under this thread. I am >>> going to report to you when/if I manage to rectify the situation. >>> >>> Best regards >>> Jarek >>> >>> >>> >>> On Fri, 3 Jan 2020 at 21:27, Ian Williams <[email protected]> wrote: >>> >>>> No it’s not spectacular really. We have a older Grob 109 which I >>>> refitted a 2400 Limbach into some years ago. It can cruise at 95 to 100 kts >>>> However the Dimona is much better at the slow speed end. It is very >>>> stable great thermalling stability. It can thermal well at 45 kts Wheras >>>> the Grob 109 begins to get uncomfortable if u get below 55 kts >>>> >>>> Best regards >>>> Ian Williams >>>> ZK-GCB >>>> >>>> Sent from my iPhone >>>> >>>> On 4/01/2020, at 8:43 AM, Jarek Steliga <[email protected]> wrote: >>>> >>>> Hi Ian, >>>> >>>> Thank you. Yes, I remember you mentioning these figures before. I am >>>> wondering if your plane is exceptionally fast. Do you think the other >>>> owners enjoy the similar performance? >>>> >>>> Best regards >>>> Jarek >>>> >>>> >>>> >>>> On Fri, 3 Jan 2020 at 19:21, Ian Williams <[email protected]> wrote: >>>> >>>>> hi Jarek, >>>>> Typically I look for close to 2800 to 2900 RPM static as part of our >>>>> pre take off checks to confirm the prop is in fine pitch >>>>> On climb out provided the airspeed is around 60 kts or so the RPM gets >>>>> to about 3200. Any more and the noise factor increases >>>>> Best regards >>>>> Ian Williams >>>>> ZK-GCB >>>>> >>>>> Sent from my iPhone >>>>> >>>>> On 4/01/2020, at 4:55 AM, Jarek Steliga <[email protected]> >>>>> wrote: >>>>> >>>>> Hello, >>>>> >>>>> I apologize for laboring the point, but what is the max static RPM on >>>>> your H36 / Limbach 2000 / Hoffman H0-V62 prop? Do all of you reach >>>>> consistently way above 2500 RPM? >>>>> >>>>> >>>>> Best regards >>>>> Jarek >>>>> >>>>> >>>>> >>>>> On Wed, 1 Jan 2020 at 12:28, Jarek Steliga <[email protected]> >>>>> wrote: >>>>> >>>>>> Hello Rob, >>>>>> >>>>>> Thank you for your reply and all the best in the New Year! >>>>>> >>>>>> Yes, I have synchronized the carbs with vacuum gauges. The readings >>>>>> were pretty consistent throughout the range of throttle opening. However >>>>>> I >>>>>> noticed how throttle butterflies will not track together as they open >>>>>> wide. >>>>>> They are both fully closed at idle but aren't aligned at full throttle. >>>>>> Should this worry me even if both sides seem to be synchronized when it >>>>>> comes to the vacuum values? >>>>>> >>>>>> >>>>>> Best regards >>>>>> Jarek >>>>>> >>>>>> On Sun, 29 Dec 2019 at 22:45, Rob Thompson <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> Have you synchronised the carbs to make sure the throttle >>>>>>> butterflies are tracking together with a full range of movement? >>>>>>> regards >>>>>>> Rob >>>>>>> >>>>>>> Rob Thompson >>>>>>> 0429 493 828 >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Mon, Dec 30, 2019 at 6:05 AM Jarek Steliga < >>>>>>> [email protected]> wrote: >>>>>>> >>>>>>>> >>>>>>>> Ian, >>>>>>>> >>>>>>>> Thank you. I will definitely look at both plungers. >>>>>>>> >>>>>>>> Best regards >>>>>>>> Jarek >>>>>>>> >>>>>>>> On Thu, 26 Dec 2019 at 00:00, Ian Mc Phee <[email protected]> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> I go on colour (av gas for testing for colour), CHT (do all 4 >>>>>>>>> digitally) and maximum deviation is 8deg C but often ass low as 5 deg >>>>>>>>> C >>>>>>>>> and EGT with a cheap dual analogue and it is of limited use. >>>>>>>>> >>>>>>>>> I seem to remember the bottom jet and needle controls fuel at 80% >>>>>>>>> power to full power and below that is the top jet controls fuel for >>>>>>>>> cruise >>>>>>>>> etc. >>>>>>>>> >>>>>>>>> I am more familiar with Bing's these days but the CD150 is >>>>>>>>> similar. 8 do know if there is any sucking of air inlet manifold it >>>>>>>>> effects both sides and not just the side of the leak. >>>>>>>>> >>>>>>>>> A bit of an aside but been having issues going onto full power on >>>>>>>>> take off and if done real slow over 15 seconds no issues. Do it >>>>>>>>> over 5 >>>>>>>>> sec engine would not go full revs at first till you had just broken >>>>>>>>> ground. >>>>>>>>> I even added extra spring to bring it better to full throttle. Then >>>>>>>>> suggested to me as was not running rich it was a pin hole in >>>>>>>>> diaphragm but >>>>>>>>> was perfect BUT on second carb I noticed some scour marks on engine >>>>>>>>> side of >>>>>>>>> the plunger with the needle. I polished the aluminium first with >>>>>>>>> emery >>>>>>>>> then worked up with 400, 600 and 1200 wet and dry. Totally fixed. >>>>>>>>> Plunger >>>>>>>>> was binding or sticking on its way up. So simple to fix. This has been >>>>>>>>> creeping up on me over 9 months. >>>>>>>>> >>>>>>>>> >>>>>>>>> Ian McPhee >>>>>>>>> +61 428847642 >>>>>>>>> Box 657 Byron Bay NSW 2481 Australia >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On Thu, 26 Dec. 2019, 09:01 Jarek Steliga, <[email protected]> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Hello Martin, >>>>>>>>>> >>>>>>>>>> I did the very opposite thing! Suspecting that it was the >>>>>>>>>> insufficient supply of fuel that caused the problem, I lifted the >>>>>>>>>> metereing >>>>>>>>>> needles all the way up from neutral (flush). This manoeuvre changed >>>>>>>>>> nothing >>>>>>>>>> except (predictably) making the plugs even blacker. The CHT behave >>>>>>>>>> normally. I am afraid the snag lies elsewhere, but many thanks for >>>>>>>>>> your >>>>>>>>>> suggestion. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Regards >>>>>>>>>> Jarek >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Wed, 25 Dec 2019 at 22:30, Martyn Cook <[email protected]> >>>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>>> Hi Jarek >>>>>>>>>>> >>>>>>>>>>> Maybe now that you have blocked the air leaks around the >>>>>>>>>>> throttle shaft the engine is running a little rich? That would >>>>>>>>>>> certainly >>>>>>>>>>> reduce your peak rpm. >>>>>>>>>>> >>>>>>>>>>> I have found getting the mixture correct on each side to be a >>>>>>>>>>> bit tricky. I adjusted the mixture on mine a bit at a time, >>>>>>>>>>> watching the >>>>>>>>>>> degree of "blackness" on the spark plugs, plus the CHT behaviour. >>>>>>>>>>> But I >>>>>>>>>>> was taking it for a flight then adjusting when back on the ground. >>>>>>>>>>> >>>>>>>>>>> Maybe others know of a way to get the mixture setting correct on >>>>>>>>>>> the ground? >>>>>>>>>>> >>>>>>>>>>> Kindest regards >>>>>>>>>>> Martyn >>>>>>>>>>> >>>>>>>>>>> -- >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> On 26/12/19 9:37 AM, Jarek Steliga wrote: >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> Hello everyone, >>>>>>>>>>> >>>>>>>>>>> I have replaced the throttle shafts and the throttle plates. >>>>>>>>>>> Fortunately it looks like no rebushing will be necessary. The >>>>>>>>>>> engine became >>>>>>>>>>> far more stable now and responds precisely to throttle control >>>>>>>>>>> inputs. >>>>>>>>>>> Clearly the badly worn out throttle shaft was (at least partly) >>>>>>>>>>> where the >>>>>>>>>>> shoe pinched. However, strangely enough, the engine will not rev up >>>>>>>>>>> beyond >>>>>>>>>>> static 2500 RPM. See the attached video. I am faced with yet another >>>>>>>>>>> conundrum. >>>>>>>>>>> max static RPM 2500.3gp >>>>>>>>>>> <https://drive.google.com/file/d/17rdy2gc83H4FCpMXqlTOlBn-KBV8kVJA/view?usp=drive_web> >>>>>>>>>>> Also the engine will not respond to throttle control beyond ca 4 >>>>>>>>>>> cm before the max power position. >>>>>>>>>>> >>>>>>>>>>> I am not sure if it's safe for me to attempt a take off as >>>>>>>>>>> before the throttle repair, the engine had reved up to static 2600 >>>>>>>>>>> / 2700. >>>>>>>>>>> >>>>>>>>>>> I am looking forward to your thoughts. >>>>>>>>>>> >>>>>>>>>>> Best regards >>>>>>>>>>> Jarek >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>
