arko66 Posted October 31, 2008 Share Posted October 31, 2008 Hi folks. I have an SC46a engine. I took an eternity over the build of my Seagull Boomerang Trainer 40 and likewise the same time to mount the engine. After reading the instruction manual and several posts on this site, I decided to flick my prop and hoped for the best! Alas, I blew my first plug, ( ModelTechnics 7 Hot) which came supplied. I still dont know what happened, I presume it was my control panel settings? I decided to then buy a glow starter that you can re-charge so as to give the correct current. Anyway, I ordered 5!, yes 5!, to be on the safe side, of the same plug. I carefully fitted it and went back and read again a few posts and the instructions without first adjusting the carb, and bbrrrppp! It spluttered into life for a second or two, although it seemed like an eternity. What elation I felt knowing the engine did have a mind of its own and come to life. Obviously it died on me and I tried to close the needle a click or two as there was what I thought quite a bit of spluttering mess emitting from the carb. This worked, for a while but then it wouldnt react at all! I was right to presume I blew another plug but for the life of me couldnt work out how, why or even still...was it my fault? Should I get the flying club instructer to set it for me or do I giv it another whirl myself? Does anyone have the exact settings for this engine model? Please be gentle with your answers as my whits are at their end. Thanks in advance.Ian Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 31, 2008 Share Posted October 31, 2008 Hi Ian, and congrats - your model and engine installation look very good!My SC engines all seemed to be happy at the main needle set around 2 turns out AT THE MOST, and in fact my 91FS one likes it only 1.5 turns out. Assuming you have not touched the idle jet setting this should be about correct for yours too. The engine may still be a little tight and new, so running it slightly richer is wise anyway, - keeps the oil flowing nicely! The plug should have the glow lead / unit disconnected as soon as the engine is running, as leaving it energised with a running engine at high revs can cause premature plug failure, and should not be necessary in most cases. Try a simple Taylor Made plug or similar generic brand - "hot" plugs are normally only used in four stroke engines to retain the heat better duting the longer cycles. I assume you are only energising the plug with a single nicd cell?Also, do you have a 3 line or a 2 line tank installation? Quote Link to comment Share on other sites More sharing options...
Hamish Posted October 31, 2008 Share Posted October 31, 2008 I'm at the same stage as you are. An observation on the photographs. Throw away the brown rubber band supplied. Get good broad 6" white ones from your model shop supplier and fit least 6 with say four longitudinally and 2 across as you have done. Keep in a container with talc powderHope a more experienced modeler will confirm what I am suggesting as I am keen to be corrected.Model looks good .Hope wind drops for the weekend Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 31, 2008 Share Posted October 31, 2008 Thats a good suggestion Hamish Quote Link to comment Share on other sites More sharing options...
arko66 Posted October 31, 2008 Author Share Posted October 31, 2008 Thanks for the comments. I use a single cell nicd and the tank has 3 tubes. I did notice that as soon as I went to remove the glow starter it died immediately. Also, after flicking, it seemed to jam after a couple of revolutions. Is that normal? It just stuck and didnt sound right. After it ran for a while it spluttered and died but I was hopeful because the first plug didnt allow it to do anything. The question about 2 line or 3 line Timbo, is that to do with the return of fuel back into the tank, because after flicking, the fuel seems to dissappear back down the line? I have bunged the "fill pipe" with a stopper for now so I dont see where the air is getting in, or is that normal too? Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 31, 2008 Share Posted October 31, 2008 Hi Ian....welcome to the wacky world of model flying. As Timbo sez it looks as though you've made a nice job of the model & engine installation......I wonder if the plug problem is down to you running too rich. I'm pretty sure your SC46 is an ABC engine (Aluminium piston, Brass, Chromeplated liner & modern ABC motors are made to very fine tolerances.....some news ones even squeak as you turn them over TDC. Effectively there is a slight taper on the bore of the liner so when the engine is hot the liner expands & the running fit is just about perfect giving good sealing between liner & piston.However when new this can cause a problem or two as new ABC engines can be very hard to start because they are so "tight" at TDC. From new they need to be run up to operating temperature as soon as possible to get the right piston liner fit & need very little actual running in.....literally a couple of tanks at a slightly rich setting is all they need. Prolonged running on a very rich setting stops the engine getting up to temp & can actually cause damage.From your description of a "spluttering mess" coming out of the carb it seems you may be running very rich....this combined with a tight new motor can raise the pressure in the cylinder above what the plug can withstand & it blows.If you have access to a tame expert this is probably the way to go...otherwise open the needle max 2 turns...probably nearer to 1.5 & try again. You want the engine to start & then run pretty much on its "normal" full power settings. One concern I have....did you get the "spluttering mess" (I presume you mean this to mean raw fuel ejected from the carb, yes?) at idle? If so it sounds like your idle mixture is a long way too rich & this is probably best left to your tame expert to sort out.......Have fun & keep posting if you need more info.........lots of very experience modellers on this forum all keen to help you..... Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 31, 2008 Share Posted October 31, 2008 I've just re-read your last post & there might be a problem here......Timbo has alluded to 2 or 3 line tank installations......there are two different methods....on the 3 line tank...(by far the best in my humble opinion!!) you have a feed for the carb....a line to the silencer, which allows "silencer pressure" to be fed into the tank to lightly pressurise the fuel & keep it flowing to the engine & a fill line to allow you to put fuel in the tank (on the 2 line system this fill line is not used & you fill the tank via the engine feed line). This fill line should be sealed after refuelling to prevent the silencer pressure escaping.Looking at your pics I see the feed & silencer lines OK & there seems to be another line running out of the tank & disappearing off the bottom of the picture...what is this??Remember you must let the tank vent...either to atmosphere or to silencer pressure. If you don't then a vacuum will build up & eventually suck the fuel away from the engine thus stopping it (which you mention in your last post....). Check your tank installation to make sure the tank can "breathe" effectively..... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 31, 2008 Share Posted October 31, 2008 yep...all good stuff there from Steve. I was indeed alluring to the tank setup and woindered if you were perhaps not allowing a "free to air" vented pipe during filling - this could easily cause the fuel to get pumped into the engine via the silencer line, and raw fuel would then cause a hydraulic lock at worst, or at best cause very rich running and "swamp" the plug with raw fuel, so effectively "putting out the fire"!I am convinced that this is a simple problem from the type we have suggested - my experience of the SC engines is excellent..... and once you have her set up right, you will be pleased. Quote Link to comment Share on other sites More sharing options...
arko66 Posted October 31, 2008 Author Share Posted October 31, 2008 Okidokee. Here we go one last time as Im not sur if I have explained it correctly.....I have a tank with 3 nipples. 1 to the pick-up for the carb, another for the silencer and one for the fill. So, If I understand correctly, the one to the silencer is actually the vent?, and if so, I do not need the fill pipe? By what everyone has mentioned, this could be my problem. I actually had gunk coming out of the silencer after I tried to put her away for the day. I tilted her up to get her into my loft and got covered in a thick mix of I dont know what. It was like the same colour as the fuel but very thick and not of the same viscosity as when I put it in. Regarding the tuning of the needle, you say I should only open her to 1/ 1/2 turns from fully closed to enable her to run when the throttle is fully closed? Golly, this is so confusing...I wish I were at a club. Im not gonna get beat on this though and going to the club, even as a last option, I will get this bird up! All your comments and tips are greatly appreciated and are ALL taken onboard my friends. Lets see what happens tommorrow. Many thanks and please keep the suggestions coming.Ian. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 31, 2008 Share Posted October 31, 2008 The 3 line system is fine - but when filling through the "spare" 3rd line, take off the line to the exhaust, and watch for fuel spurting out of that one when she is filling /full. If you leave it on, all that raw fuel is going in the exhaust and could end up in the engine. When full, put the tubing back on the exhaust nipple, and seal up the filler line WITH A PROPER FUEL "DOT" OR PLUG - NOT JUST AN OLD SCREW Air can, and does, leak in past the threads of a screw. The needle valve should be adjusted when the engine is flat out, carby fully open, - NOT when it is at idle. Quote Link to comment Share on other sites More sharing options...
andy watson Posted October 31, 2008 Share Posted October 31, 2008 As a published RCME expert on newbies and IC engines here is my advice.1) Take it down to the club2) Get the assorted masses to set up your engine for you (ignore all the contradictory advice- just leave them to it)3) Once they have it running, just leave it alone.That really is all there is to it. Quote Link to comment Share on other sites More sharing options...
Paul Adams Posted November 1, 2008 Share Posted November 1, 2008 The model looks good. I read in your last post that "I wish I were at a club. Im not gonna get beat on this though and going to the club, even as a last option, I will get this bird up!" I would definitely recommend going to a club and not trying to get the model in the air yourself. I remember my first RC model, it flew for about 10 - 20 seconds before it came back to earth and was totally written off. If I had taken it to a club, it would have been test flown by an experienced fly-er to trim the model out. (First flights can be a bit like a roller coaster until you get the trims set, so that it will fly straight and level. If you have not flown before and you have a model that is out of trim, the probability of the model surviving the first flight is very remote). You will also find that being a member of a club adds to the flying experience, see other models flying, talk to people etc as well as being thought how to fly. Good luck with the model, have flown these myself and you will enjoy. Paul Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted November 1, 2008 Share Posted November 1, 2008 Is that a new method of training being "thought how to fly" sounds interesting Quote Link to comment Share on other sites More sharing options...
arko66 Posted November 1, 2008 Author Share Posted November 1, 2008 Thanks everyone. I am definately gonna take the sound advice and get down the club and let the pros sort it for me, Ive heard that they are only too willing to share their experience to a noob. Once Ive got it sorted I hope to be posting my blog of the build through to the maiden voyage. Many thanks once again. CheersIan Quote Link to comment Share on other sites More sharing options...
Hamish Posted November 1, 2008 Share Posted November 1, 2008 Got my first flight in today in perfect conditions.First flight lasted about 10 secs then engine stopped. After a fiddle the second flight lasted sightly longer with a dead stick into the flying field. Changed engines and all went well from there. After experienced members set up buddy box was given my first shot, GREAT. Consider time spent on the SIM has benefited me Both engines were Irvine 40s from ebay given glowing pedigree however this is a chance you take. Although the second Ivrine is going OK I have a 10 year old OS 48FS Surpas that was given to me for a birthday along with a bi-plane that is still to be completed. It has not seen fuel and I would ask the experts if this would be suitable for the Boomerang. Not being picky Ian, but I was told the nice blue nose cone did not meet the requirements as it was to pointed. Fortunately I had another and changed it although the club were not making it an issue for the day but it would need to be changed for next visit. Cant wait till my next trip to the field.I have had absolutely no regrets at waiting for experienced fliers to point me in the correct direction and you will appreciated the benefits, IT CAME HOME IN ONE PIECE .I used a Sanwa RD6000 for the master and a VG600 for the trainer. Trims are way out in the trainer, no adjustment left and will need to spend some time working out how get them compatible.You will enjoy yourself! Edit Speeling Quote Link to comment Share on other sites More sharing options...
flytilbroke Posted November 1, 2008 Share Posted November 1, 2008 Hi Ian and Hamish. I hope you have as much fun from Model Flying and Building as I have had.Try and "pick" any "experts" who do not seem to twiddle a lot with thier engines . The advice above has all been pretty sound and due to the advisors not being present with you they can only give indirect help."Taylor made" plugs were and possibly are, still cheaper than some of the more commonly used types and they are a good basic plug. OS 8, Enya 3 are pretty good for basic two stroke use. Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted November 1, 2008 Share Posted November 1, 2008 I think you will find the 48FS a bit underpowered for the Bommer. I have an SC52FS in mine and that is about right. Quote Link to comment Share on other sites More sharing options...
arko66 Posted November 2, 2008 Author Share Posted November 2, 2008 Hamish McNab wrote (see) Not being picky Ian, but I was told the nice blue nose cone did not meet the requirements as it was to pointed. That was funny Hamish, I bet you didnt realise what you typed. Hahaha. (as in picky, nose, get it?) Well, the decision has been made by my missus to get down the club in Llantrisant and get both my boys and my fees paid for 2009, so there is no turning back now. Lets hope next week I'll be up flying. Quote Link to comment Share on other sites More sharing options...
Hamish Posted November 2, 2008 Share Posted November 2, 2008 No Ian, thanks, this was a typo(brain) error, but at least the message got through.Super day up here but unfortunately I have a Kart meeting today to support my grandson (Scottish Champion) and I get great pleasure out of both sports.Have a good day and roll on next week Quote Link to comment Share on other sites More sharing options...
arko66 Posted November 2, 2008 Author Share Posted November 2, 2008 Have a great day Hamish and will be keeping my thumbs crossed for your grandson. Quote Link to comment Share on other sites More sharing options...
Hamish Posted November 2, 2008 Share Posted November 2, 2008 Just an update on my failing Irvine 40 and a look for advise.The take off nipple from the exhaust was damaged when I got the engine. I made a new one out of a bolt and drilled it 1.5mm with it partially obstructed, my error. I suspect there was insufficient pressure to the fuel tank thus causing the engine to stop.I have had a look at another exhaust and the hole is 2mm in diameter.Any advise gratefully received.ps Grandson came 3rd & 1st in heats and 3rd over line in final. Now if you want a real challenge, getting a kart to handle and engine to run spot on all at the same time is mind blowing. I just stand back in admiration Quote Link to comment Share on other sites More sharing options...
arko66 Posted November 2, 2008 Author Share Posted November 2, 2008 Nice one. Congrats. That must be some hobby and expensive, sorry, gone off topic. Quote Link to comment Share on other sites More sharing options...
Hamish Posted November 2, 2008 Share Posted November 2, 2008 Thanks very much Ian and still staying off topic.Karting can be very expensive but it depends on the depth of your pocket and what you want out of the sport, like this sport which can be coppers or mega bucks. My sons only hobby is Karting and that is where he spends his money. As it is my only grandson I chip in now and again.Years ago I used to do F2 stock cars which I built myself from scratch. Did not win many races but the satisfaction of passing another competitor who had spent mega bucks made up for it.On TopicSpent this evening on my old Maricado that I am renovating. Fitted a new wiring harness and altered the exhaust which I suspect was the fuel cut out problem.Slightly off topic but followed an ebay bid for an engine that eventually sold for a few pounds less than new???. Also a posting for a secondhand engine priced more than a new - if he sells good on him Quote Link to comment Share on other sites More sharing options...
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