Ernie Posted February 18, 2008 Share Posted February 18, 2008 Help you engine experts, I'm a bit alone here, in France, so, I turn to you for advice. First I'm not at all new to all of this, so I'm pretty confident that things are set up OK. I'm running a new quality 60 size 2 stroke..Run in (about 2 hours now) as per manufacturers instructions. I'm running on 10% because I run everything on that...Because of that, and as per the instructions, I've put a shim in the head..Its been running fine, until last session. Now it starts first flick, ticks over a dream, opens up to about half throttle, and then as I get near the top it dies. It is worse in the air (boy, I'm getting good at deadsticks ) I've checked the tank for leaks, jammed clunk etc., level is just on the centre of the carbie, New fuel tubing, fresh fuel, well filtered, new OS no 8 plug..It starts on about 2 1/2 main needle, I havent touched the idle, and te fuel is getting through without any air bubbles....Any thoughts?ernie Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 18, 2008 Share Posted February 18, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Ultymate Posted February 18, 2008 Share Posted February 18, 2008 I would think it's about time to adjust your idle mixture usually after a couple of Hrs running in there comes a time when you have to bite the bullet and adjust said idle mixture Quote Link to comment Share on other sites More sharing options...
Ernie Posted February 19, 2008 Author Share Posted February 19, 2008 Thanks Eric and Ultymate, It's good to be able to discuss these thingsNo cowling, Its totally exposed...2 1/2 turns on the needle, some oil coming out with the exhaust...pressure from the silencer...checked for leaks, but will do it again...checked needle, but will do again..maybe its a wee bit hot, I can just touch the head...I thought the idle needle was only effective just above tickover, but I'll give it a try.. Quote Link to comment Share on other sites More sharing options...
Doug Ireland Posted February 19, 2008 Share Posted February 19, 2008 Sounds like a classic "lean-out" stoppage when the engine unloads in the air. Peter Miller went through this in some detail in his article in RCM&E. Quote Link to comment Share on other sites More sharing options...
Ernie Posted February 19, 2008 Author Share Posted February 19, 2008 Hi Guys, Thanks.....Yup nose up.....I'd have thought 2 1/2 turns OK (manufacturers instructions) I'll set it all up from scratch this afternoonernie Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 19, 2008 Share Posted February 19, 2008 Bet its an SC the best value engines (not motors ! ) I've ever bought 2 temps et 4 temps Wouldn't buy anything else .Yes, keep it running on the slightly more than slightly rich side with pressurised tank & I can't see you going wrong. Except Maybe I'm wrong about the engine .!Bloody lectrics are doing my head in .Hope this helps to resolve what I've been doing for ------- years with diesels & glows.Never--- Never run even slightly lean -- Ever! It'll lean out if anything NOT richen up after TO (lots of reasons for that have been covered on previous discussions on here ) Quote Link to comment Share on other sites More sharing options...
Ernie Posted February 19, 2008 Author Share Posted February 19, 2008 Non Myron, It's not an SC I don't want to say the makers name, because, I'm a great fan of theirs, and I'm sure its me being stupid, rather than an inferior product. ernie Quote Link to comment Share on other sites More sharing options...
FlyinBrian Posted February 19, 2008 Share Posted February 19, 2008 Have you tried a new glow plug? Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted February 19, 2008 Share Posted February 19, 2008 They only have "bougies" in France ! Maybe that is Ernie's problem .So what , you can go out in France ,park up anywhere ,have a "COUP DE ROUGE" end up home eventually & try again Manjana (le prochain jour or is it le jour prochain ) who cares .? Que la France me manque, ou quoi ? Bonsoir a tous ,a la prochaine ! A bientot ! Quote Link to comment Share on other sites More sharing options...
Ernie Posted February 19, 2008 Author Share Posted February 19, 2008 Hi Brian, yes an OS no 8 Bonsoir Le grincheux...I'd talk to the local flyers, if my french was up to "how many clicks on the idle needle" merci tout le monde Quote Link to comment Share on other sites More sharing options...
David Martin 2 Posted February 20, 2008 Share Posted February 20, 2008 Hi Ernie,I had exactly the same symptoms when my muffler pressure nipple had hardened the fuel tubing over it after about 20 flights. The engine was fine until it was starved of air entering the tank, all was ok up to mid throttle and the initial nose up full throttle test but it would die in the air at full throttle, usually on the climbout....You say you've renewed the tubing throughout, make sure the mufflers pressure nipple hasn't blocked, once an engine has been tuned with a pressure feed, removing the pressure and it all goes up the wall. Another cause can be the tank pressure escaping through a u/s filler bung.Good luck mate, keep us informed... Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted February 20, 2008 Share Posted February 20, 2008 did you replace the tube inside the tank - otherwise could be the clunk jammed at the front of the tank, kinking the fuel line perhaps? Or a foreign body in the needle orifice - try flushing it through? Loose carb clamping screws or carb slipped creating an air leak? Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted February 20, 2008 Share Posted February 20, 2008 Yes, the tube in the tank can easily get a hole where it is fitted to the brass outlet tube. Had that recently.There is another possibility, did you change the prop. an unballanced prop can cause the fuel to foam and that will result in a lean run.I don't think I covered this subject in RCM&E. Maybe someone else did. Quote Link to comment Share on other sites More sharing options...
Kiwi 1 Posted February 20, 2008 Share Posted February 20, 2008 I wasted a whole day with this type of problem on Saturday. My problem turned out to be that the fuel line inside the tank had expanded. (Like you would believe that if you read it) Anyhow this eventually meant that the clunk ended jammed in a place where the fuel didn't reach. (Of couse it wouldn't jam where the fuel could reach) I only believed that this was the cause when on trying to drain a near full tank nothing came out. The excitement of solving the problem somewhat tempered by the fact that getting a tank out of an i/c model is not a quick, easy, painless or enjoyable task. If that 5S Lipo were any cheaper..... Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 20, 2008 Share Posted February 20, 2008 Hi Ernie, if your motor is anything like an OS you will need to gradually screw in the idle needle during the first hour or so of running because as the piston seal builds up the mixture draw will increase making it richer on idle. To test, allow it to idle for 30 sec then open the throttle slowly (about 2 sec). If it splutters and takes time to come up to full revs then it is too rich on idle. Screw in the needle 1/8 turn at a time if it is a twin needle carb, or out if it is an airbleed type such as a YS. If the motor stops immediately when opening quickly, then it is too lean on idle. We need to know the type of motor. If it is a YS and the above does not work, send it back. Also, if you are using a tuned pipe you will need to use an Enya No. 3 plug. Quote Link to comment Share on other sites More sharing options...
Ernie Posted February 23, 2008 Author Share Posted February 23, 2008 Thanks GuysI'm on to it..I've had it all in bits. All he plumbing is OK, all the engine bolts are tight, Tank is fine, and I've cleaned out the carbie. As soon as I can get out, I'll run it very rich, and see if the lean run theory is correct. The problem was at 2 1/2 turns on the main needle, surely that is rich enough. If that doesn't work, I'll fiddle with the idle needle..I'll let you know.ernie Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 23, 2008 Share Posted February 23, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted February 24, 2008 Share Posted February 24, 2008 How right Eric is. In the day before we used starters one could tell an awful lot justr by flicking the engine over. We could tell when it was about to fire or run, when it was rich or dry. I still hand start diesels because the feel is so important.I never used a starter until a few years ago when some left me one and I fitted it into my flight box.And talking of hand starting. You never get a bad injury from hand starting an engine, it is always once the engine is running when the serious damage is done.I can remember a time when I dabbled in C/L sped flying. I could hand start my Super Tigre G21/29 5cc speed engine on a 7" X 10" prop on 25% and even 50% nitro. I loved that engine! Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 24, 2008 Share Posted February 24, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 24, 2008 Share Posted February 24, 2008 Remember that you must have the main mixture needle set for max. revs before you start to fiddle with the bottom end. The 2 1/2 turns is just a guide. When you have the idle set correctly the motor should snap open to full revs immediately. Quote Link to comment Share on other sites More sharing options...
David Martin 2 Posted February 26, 2008 Share Posted February 26, 2008 You've jinxed me Ernie...!!!!!!I had my first deadstick in nearly a year on my OS yesterday, it'll run fine at level and nose down right through the rev range, but nose up and it'll die after about 5 seconds..My money's on a split in the cluncked pickup pipe where it joins the metal tube at the bung.....diving in later today and testing Wednesday....I've got a niffty little Cox 049 Q.. (something or other) that has a ring silencer and coiled spring start Eric. That was always a bit tempermental and way down on power compared with my Enya 049 with R/C carbie, now that IS noisey for a tiddler..! Quote Link to comment Share on other sites More sharing options...
Mike Stevens Posted February 26, 2008 Share Posted February 26, 2008 I was taught by a PAW 1.49 spinning a 7x6 nylon prop. If you weren't careful, it would bite, but treat it correctly and it was a pussycat. - I never did get a Cox 049 to do more than go BRRRRAP! A friend of mine back in school days nearly lost the top off his knuckle on a PAW 1.49 - split right open when adjusting the needle. We were also using 2.5s and 3.2BR's - never had a 'serious' injury but lots of rapped thumbs and prop cuts from a lock up due to flooding/over compression .I took the spring off my Cox Black Widow but can get it to start easy enough with a flick or two even though it has a habit of running backwards more than forwards! Sounds like an angry bee..lolMike Quote Link to comment Share on other sites More sharing options...
Ernie Posted April 29, 2008 Author Share Posted April 29, 2008 Hi guys, So sorry about the lack of response from me, but, the weather has been bleak, so,I have not been able to try all of your suggestions. But now, we have a French spring, and It's interesting, I'm now getting great results on about 3 to 4 turns open on the main needle (way over the manufacturers instructions) Now, why is that?ernie Quote Link to comment Share on other sites More sharing options...
Former Member Posted April 29, 2008 Share Posted April 29, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.