darren ctsw Posted January 5, 2011 Report Share Posted January 5, 2011 I am having issues with my engine start up and shut down. Facts, I don't have a slipper clutch or soft start, it is a 2007 model. When starting it really seems to rock the whole aircraft, again on shut down. I have had 2 carb rubbers go, and i have found today that on my electric modules the moulded fixed bracket have both broke at one end nearest the bulk head, also a couple of wires have broke. Also, when I replaced the carb rubbers the main engine bolt was loose. Assistance and advice please, thanks Darren Link to comment Share on other sites More sharing options...
FastEddieB Posted January 5, 2011 Report Share Posted January 5, 2011 This list is from the Soft Start Module installation manual (from the Bullyhawk site): Other Causes of Starting Problems: The following things can also influence poor starting including causing Kick back during start up: 1. Low cranking speed. 2. Poorly charged or defective battery. 3. Battery of insufficient output (starting current or capacity). 4. Incorrect oil grade. 5. Incorrect use of oil additives. 6. Lead contamination internal to the engine. 7. Defective starter motor. 8. Faulty starter solenoid. 9. Incorrect trigger gap. 10. Loose or damaged trigger. 11. Incorrect installation of the magneto flywheel. 12. Loose or damaged flywheel. 13. Poor connections of any electrical component. 14. RF interference. 15. Battery charging system operating incorrectly. 16. Damaged or worn sprag clutch or sprag clutch housing. 17. Wires of excessive length to the starter motor. 18. Bad or corroded electrical connections. 19. Wires of insufficient current carrying capacity ie. too small a diameter or too high a resistance cable type. 20. Incorrect maintenance of the gearbox (friction toque incorrectly adjusted or preload on disc springs in gearbox incorrect). 21. Poor carb set up. 22. Blocked carb jets. 23. Blocked vent off carb bowl. 24. Improper use of the mixture enrichment (choke). 25. Insufficient movement of choke. 26. Resonance between engine & propeller. 27. Mal-aligned crankshaft. 28. Damaged bearings. 29. Bent propeller shaft. 30. Damaged gears. 31. Out of balance carburettors. 32. Fouled, old or incorrectly gapped spark plugs. 33. Incorrect spark plugs. Whew! Link to comment Share on other sites More sharing options...
Mac Bowden Posted January 5, 2011 Report Share Posted January 5, 2011 Hi Darren, Sorry for your trouble. I've had my CT for 18 months now and all was well till an enforced grounding stopped me from flying for 2 months. Once back in the air I experienced a lot of mag drop and vibrations. After a lot of head scratching and a process of elimination and cross-overs of ignition modules and trigger plugs, I traced the fault to some broken wires at the ignition module plugs and a combination of dirt in one carb which made balancing the two carbs pretty tricky. I too had a damaged ignition module mounting lug due to vibration but since doing all the above repairs the engine is back to its silky smooth old self. If you PM me with contact details i'll give you a ring for a chat. Mac Link to comment Share on other sites More sharing options...
Ed Cesnalis Posted January 6, 2011 Report Share Posted January 6, 2011 I am having issues with my engine start up and shut down. Facts, I don't have a slipper clutch or soft start, it is a 2007 model. When starting it really seems to rock the whole aircraft, again on shut down. I have had 2 carb rubbers go, and i have found today that on my electric modules the moulded fixed bracket have both broke at one end nearest the bulk head, also a couple of wires have broke. Also, when I replaced the carb rubbers the main engine bolt was loose. Assistance and advice please, thanks Darren Darren, You may have some issues. When all is well I find I can start up "softer" if I get my choke setting just right. I often begin full choke and as soon as i start to crank i advance it looking for that sweet spot. I find a pretty violent rough spot if i don't advance far/fast enough. On shut down I kill one mag and wait i few seconds before shutting down. Link to comment Share on other sites More sharing options...
Jeremy MacGregor Posted January 6, 2011 Report Share Posted January 6, 2011 How many hrs are on the engine and how many since you gearbox has been inspected? I find it hard to believe that your 2007 does not have a slipper clutch in it but I am willing to give you the benefit of the doubt. If that is the case and you do have high time on the gearbox ( over 400hrs ) I would strongly recommend having you gearbox inspected and the disk springs replaced. If you have a slipper clutch in your gearbox your inspection should be at 600 or at 1000 depending on your TBO. But if not then Rotax wants it inspected at 400hrs. The reason for this is that on configurations with out the clutch there are only(2) disk springs instead of (3) and in turn the springs wear out 30% quicker. Improper gearbox tension is the #2 cause of engine vibration that can lead to kick back and hard starting. Low powered batteries are of course #1 but once the engine is started there should be no noticeable ruffness. Your carbs should also be cleaned and inspected every 200hrs with a carb balance every 100hrs. Again you had mentioned you have a noticably ruff shut down, these engines have a 10.5:1 compression ratio so the ruff shut down is common but if it has gotten progressively worse over Time and you have ruled out engine mounts it is almost certainly going to be gearbox tension. Also make sure your IDLE is set to 1800rpm when warm, any higher and your choke system effectiveness will be reduced. Higher Idle rpm can also increase shut down vibrstions, but again if it's been getting worse over time and you have more than 3-400 hrs I would consider other issues. Check float bowl for contamination, if you see and varnish at all then replace your Idle jets. Bully hawk soft start is approximately $200 USD and takes all of 15 minutes to install, cheap insurance considering the price of aircraft and engine. Link to comment Share on other sites More sharing options...
Roger Lee Posted January 6, 2011 Report Share Posted January 6, 2011 I agree with Jeremy. A 2007 912ULS 100 hp has a gearbox clutch. They have been coming this way for the past several years on the 100 hp. If you have a 912UL 80 hp then you don't have the gearbox clutch. Link to comment Share on other sites More sharing options...
Mac Bowden Posted January 7, 2011 Report Share Posted January 7, 2011 Darren is correct when he says he doesn't have a slipper clutch fitted, they aren't fitted as standard. Over in the U.K., in order to qualify as a microlight, the unladen weight of the aircraft is critical and without a BRS fitted the aircraft must be below 267 Kgs empty. We don't even have the luxury of 2 coats of paint on the finished aircraft .... it really is that critical ! People have retrofitted slipper cluthes but when the time comes to get their aircraft weighed for permits they usually remove their spats, GPS and any after market goodies that might put them over weight. Ahem ... as soon as the test is over the goodies all go back on again for another couple of years. . . . but that's another story. Link to comment Share on other sites More sharing options...
ozairangel Posted January 7, 2011 Report Share Posted January 7, 2011 I am having issues with my engine start up and shut down. Facts, I don't have a slipper clutch or soft start, it is a 2007 model. When starting it really seems to rock the whole aircraft, again on shut down. I have had 2 carb rubbers go, and i have found today that on my electric modules the moulded fixed bracket have both broke at one end nearest the bulk head, also a couple of wires have broke. Also, when I replaced the carb rubbers the main engine bolt was loose. Assistance and advice please, thanks Darren Link to comment Share on other sites More sharing options...
ozairangel Posted January 7, 2011 Report Share Posted January 7, 2011 Hi Darren, I too had no slipper clutch on my late 2006 Sw. Although it was standard at that time the original purchaser had it removed by the factory as he believed it was fitted to protect against prop strikes!!. When i purchased aircraft I found start up to be an unbelieveable experience in harshness, vibration and generally unaircraft like roughness to the point where the shaking caused the carby needles to unseat and flood the engine. About this time Rotax isssued a service bulletin on the gearbox necessitating its removal when I discovered "no slipper clutch". I had slipper clutch fitted with service mods. The difference was simply amazing. Unbalanced Carbys wil make a big difference to idle I have found but the absence of slipper clutch May be the major part of your problem. Link to comment Share on other sites More sharing options...
Runtoeat Posted January 7, 2011 Report Share Posted January 7, 2011 I'll jump in and agree with the slipper clutch theory for roughness. A local guy with a EuroFox with 912ULS had a start up shake so bad that it was throwing fuel out of the carb vent tubes. The cause was finally traced to springs in the slipper clutch which had lost their temper. Rebuild of the cluctch solved the problem. I'm thinking that the 912ULS, due to it being a light engine with high compression, produces a lot of torsional vibration and the mass and frictional damping of the clutch is needed to tame this. The 912 80hp may not need the clutch due to low compression? There could also be concerns with carb condition and balance as others have also indicated. As a side note, after start and warm up, his engine ran fine. Just acted up when cold. The first indication that it was clutch related was when someone tried warming up the gearbox with a hair dryer before starting. The start up and initial run with a warm gearbox was a non event. The heat apparently brought back enough of the slipper clutch spring tension that the clutch functioned correctly and did not work against the engine torsionals? Link to comment Share on other sites More sharing options...
Roger Lee Posted January 7, 2011 Report Share Posted January 7, 2011 If the pilots in the UK and other parts of the world have to have the clutch removed due to a weight consideration then I'll have to eat my words, but this is a huge dis-service to these folks. I know Rotax must not be happy about it in the 912ULS, but the plane Mfg. is doing the ordering. It is a shame that the weight is so close that you have to remove important operational equipment. The owner will pay for this in the long run due to all that extra transmitted vibration. Sounds like a few countries should lobby to have the weight limit raised if that would be possible. It's a major cost and safety issue. Link to comment Share on other sites More sharing options...
darren ctsw Posted January 10, 2011 Author Report Share Posted January 10, 2011 Thanks guys for the advice, I have decided to fit the following, here is the quote, do you think this will resolve the issues, the chute means I can add the extra weight. Rotax Overload Clutch Assembly. 996 889 £546:77 Fitting 3 hours £ 96:00 Net £642:77 Soft Start Module £133:00 Fitting 2 hours £ 64:00 Net £197:00 3SSPLJU Magnum Lightspeed Parachute £3062:22 3KV24JU 2.4m Arimidleine rope £115:00 3P36JU 3.6m Polyamidleine rope £95:00 KB7010010 CTSW Mounting frame £185:00 KB7010202 Cover plate £15:00 KB7010201 Bracket £15:00 CTSSPB Forward Bridle set £205:00 CTMST Support tube £15:00 SUN Sundries £25:00 Fitting cost to CT & CTSW £450:00 Net £4182:22 Total net £5021.97 Vat £1004.39 TOTAL £6026.36 let me know what you think! Link to comment Share on other sites More sharing options...
darren ctsw Posted January 10, 2011 Author Report Share Posted January 10, 2011 Hi Darren, Sorry for your trouble. I've had my CT for 18 months now and all was well till an enforced grounding stopped me from flying for 2 months. Once back in the air I experienced a lot of mag drop and vibrations. After a lot of head scratching and a process of elimination and cross-overs of ignition modules and trigger plugs, I traced the fault to some broken wires at the ignition module plugs and a combination of dirt in one carb which made balancing the two carbs pretty tricky. I too had a damaged ignition module mounting lug due to vibration but since doing all the above repairs the engine is back to its silky smooth old self. If you PM me with contact details i'll give you a ring for a chat. Mac here is the quote to fix the problems Mac, what do you think? Rotax Overload Clutch Assembly. 996 889 £546:77 Fitting 3 hours £ 96:00 Net £642:77 Soft Start Module £133:00 Fitting 2 hours £ 64:00 Net £197:00 3SSPLJU Magnum Lightspeed Parachute £3062:22 3KV24JU 2.4m Arimidleine rope £115:00 3P36JU 3.6m Polyamidleine rope £95:00 KB7010010 CTSW Mounting frame £185:00 KB7010202 Cover plate £15:00 KB7010201 Bracket £15:00 CTSSPB Forward Bridle set £205:00 CTMST Support tube £15:00 SUN Sundries £25:00 Fitting cost to CT & CTSW £450:00 Net £4182:22 Total net £5021.97 Vat £1004.39 TOTAL £6026.36 Link to comment Share on other sites More sharing options...
Roger Lee Posted January 10, 2011 Report Share Posted January 10, 2011 Hi Darren, $9351 US dollars is quite a sum. The parts you are adding are good additions and should help. I hope they are what you need to actually fix your problem. The clutch and soft start should make a pretty good difference. Link to comment Share on other sites More sharing options...
ozairangel Posted January 11, 2011 Report Share Posted January 11, 2011 At the risk of being an absolute smartarse, the parachute wont help with the start up....... do the clutch and soft start , then think about the chute Link to comment Share on other sites More sharing options...
darren ctsw Posted January 11, 2011 Author Report Share Posted January 11, 2011 At the risk of being an absolute smartarse, the parachute wont help with the start up....... do the clutch and soft start , then think about the chute Here in the Uk we have a weight limit of 450kg, so flight design uk, take alot of the good stuff off to make the weight and stall speed, i can understand the "smartarse" comment, but the chute in the uk gives me an increase wieght limit of 22.5kg, so the chute weighs 12kg, so I have the extra kg's for the clutch and soft start, crazy i know !! Link to comment Share on other sites More sharing options...
Mac Bowden Posted January 11, 2011 Report Share Posted January 11, 2011 Ozairangel, I nearly fell into the same frame of mind as yourself with regard the list Darren intends to install in his plane. Darren is correct in that he would be flying illegally if he fitted extra equipment without fitting the chute in order to gain the extras kilos of weight allowance that the chute gives when unladen. It means as much as 10 kilos of extra equipment/fuel etc could be fitted and still be legal. Providing all the wires to the ignition circuits are intact, the carbs are clean and set and your battery is not the stupid CYCLON one that came with the CT (fit an Odyssey instead )then the soft-start and clutch should smooth it out. MAC Link to comment Share on other sites More sharing options...
darren ctsw Posted January 22, 2011 Author Report Share Posted January 22, 2011 Update Plane has been dropped off to Sywell, chute, soft start and slipper clutch being fitted, fingers crossed, my CTSW is even more enjoyable as the guys in the states say there's are !, will let you know. On another note, my plane has had the matco brakes fitted does anyone know the easiest way to refill and bleed the brakes, as mine are useless ? Darren Link to comment Share on other sites More sharing options...
Runtoeat Posted January 23, 2011 Report Share Posted January 23, 2011 Darren, Roger Lee posted a way to bleed brakes and this was on another forum as I recall. Basically, bleeding aircraft brakes is reverse from automotive. One pushes new fluid, and trapped air, out of the brake system by starting at the bleeder and pushing new fluid up thru the system. The FD maintenance manual describes the procedure. Push fluid thru, close the bleeder, pump the brake lever, open the bleeder, push more fluid, etc. until all air is out of the system. Many have fashioned pressure brake bleeding systems which will force new fluid into the bleeders and speeds up this task. Link to comment Share on other sites More sharing options...
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