Joe Tosh Posted December 24, 2007 Share Posted December 24, 2007 (edited) Hi, First, if my english 's poor sometimes, sorry for that, I'm from Belgium and I speak Dutch... I'm a newbee in nitro-cars. Have read and watched all the tuning- howto's and videos but I just cannot get my brand-new RTR Firestorm to react smooth on the throttle. When I set everything to factory-settings (HSN & LSN flush), the engine runs quite well, allthough lots of smoke and nitro-spillage through the exhaust. Applying full throttle (at low and mid-speeds) mostly stalls it, or makes it (don't know the right word) sound like it's drowning (is this called "bogging"?) The only way to achieve high speeds is gradually applying throttle pressure. Even then it's often "drowning" Starting is virtually impossible without opening the throttle a bit. As for the tuning: The tiniest bit of leaning on the HSN makes everything worse, even just 1/8 clockwise and the engine stalls even quicker. Same thing with the LSN. Along these tuning-attempts I'm also trying to keep a steady idle, which isn't that simple either. Often when tuned, the engine also stalls when braking. I use the stock-glowplug, which is a HPI R5, and Tornado fuel 25% (as recommended in the manual). Have tried a few Rossi R3 medium glowplugs from my local hobby-store, but starting the engine is worse with that plug. I also 've got the idea this plus doesn't glow as hard as the stock R5 supplied in my RTR firestorm. Of course it's f*cking cold at the moment (approx 2-3 °C), but that shouldn't make tuning impossible isn't it? Any suggestions or ideas? What am I doing wrong? Thanks a lot folks! Edited January 7, 2008 by Joe Tosh Quote Link to comment Share on other sites More sharing options...
HappyLad Posted December 24, 2007 Share Posted December 24, 2007 Hi - and welcome to the forum. I too have a Firestorm and have had some of the problems you describe. I've had high speed stalls before, but this has been due to the pressure line from the exhaust back to the fuel tank getting disconnected. - check that this return pipe is OK and isn't blocked or damaged. stalling when braking: first, check your linkages and how open the carb is when brakes are applied. I had to set up the linkages again after a few days running as the servo somehow managed to loosen things. Next, check your clutch. I had the clutch spring fail which meant that every time the car stopped the engine would too. Try these and let us know if they fix your problem. Quote Link to comment Share on other sites More sharing options...
Mr Terminator Posted December 24, 2007 Share Posted December 24, 2007 Hi mate,weather does affect tuning but thats same with warm and cold weather.The air is a lot more dense during cold weather so adjust the mixture to the rich side accordingly..... Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted December 24, 2007 Author Share Posted December 24, 2007 Hi - and welcome to the forum. I too have a Firestorm and have had some of the problems you describe. I've had high speed stalls before, but this has been due to the pressure line from the exhaust back to the fuel tank getting disconnected. - check that this return pipe is OK and isn't blocked or damaged. stalling when braking: first, check your linkages and how open the carb is when brakes are applied. I had to set up the linkages again after a few days running as the servo somehow managed to loosen things. Next, check your clutch. I had the clutch spring fail which meant that every time the car stopped the engine would too. Try these and let us know if they fix your problem. Thanks for feedback. Checked the pressure line and its ok. I shortened it, it was quite long and had an unneeded twist in it, held together with plastic clamps. I then loosened and twisted the fuel nipple on the carb to the right, to the other side of the airfilter, as the factory mount stucked it between the cylinder head and the airfilter. Now it's got more space and doesn't touch the hot cylinder head anymore. I set up the linkages again, and recentered the servo and the stalling when braking is a lot better, allthough I have to keep up a tiny bit high idle, but this looks ok for now I guess. So I guess the clutch is fine, drove it this morning for 2 tanks and had just 1 stall when braking. How do you check the clutch spring anyway? Will check the manual, I know... My biggest issue is still the "drowning" when applying full throttle (hope you know what I mean with that! ) Hi mate,weather does affect tuning but thats same with warm and cold weather.The air is a lot more dense during cold weather so adjust the mixture to the rich side accordingly..... OK, sounds quite logic indeed, thanks! Maybe it's so cold this time of year I just have to forget leaning the mixture at the moment? The factory settings are very rich, and apart from responding good to full throttle it runs quite stable like that. Maybe I just have to wait for hotter weather to lean the engine? Any comments on glowplugs and fuel I use? Or is this ok? I've read a lot here on nitro percentages, but the manual says 20-25% nitro, that's what I use. Could an incorrect glowplug affect my throttle response? I've ordered a temp gun on ebay to check engine temperature. Quote Link to comment Share on other sites More sharing options...
smithy1135 Posted December 24, 2007 Share Posted December 24, 2007 If its bogging then it can be lean or rich. When you apply throttle does it sound groggy as if its loaded with fuel or does it just rev and not move? If its the first one then its rich, second one then its lean. Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted December 24, 2007 Author Share Posted December 24, 2007 If its bogging then it can be lean or rich. When you apply throttle does it sound groggy as if its loaded with fuel or does it just rev and not move? If its the first one then its rich, second one then its lean. It's definitely the first thing! As if it's loaded with fuel yes!! I can only achieve high revs when applying the throttle gently and steadily. I think I'm starting to onderstand the meaning of 'bogging' But, that's my problem, If I lean it in 1/8 steps it's not gettin' better at all, on the contrary, it's starting to stall more... Quote Link to comment Share on other sites More sharing options...
joe of loath Posted December 24, 2007 Share Posted December 24, 2007 It's definitely the first thing! As if it's loaded with fuel yes!! I can only achieve high revs when applying the throttle gently and steadily. I think I'm starting to onderstand the meaning of 'bogging' But, that's my problem, If I lean it in 1/8 steps it's not gettin' better at all, on the contrary, it's starting to stall more... hmm...how much smoke is coming out of the pipe before it stalls? i though i had the same problem, but actually my LSN was too rich, and to compensate i set my HSN too lean, resulting in not getting full throttle. the truck's good though isn't it just don't drive into any kerbs, it doesn't like full frontal attacks so to speak. Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted December 26, 2007 Author Share Posted December 26, 2007 hmm...how much smoke is coming out of the pipe before it stalls? i though i had the same problem, but actually my LSN was too rich, and to compensate i set my HSN too lean, resulting in not getting full throttle. the truck's good though isn't it just don't drive into any kerbs, it doesn't like full frontal attacks so to speak. Euh... I'd have to watch carefully to notice how much smoke is coming out just before it stalls... But good advice though, I'll leave the HSN flush and will only lean my LSN once, to see how it responds. Overall I get the impression that there's a lot of smoke in low to medium high revs, and not that much in high revs, although I presume the smoke's not that visible when you car does 40 mph... Temperatures are up (8°C today), will drive it tomorrow to see if there's any improvement when trying to lean. As for it being though, wouldn't know, I just drove it, no jumps, no bashing yet. I'd like to have it run well before I start with the bashing! Kerbs, hmm. Isn't there a front bumper available? My old Tamiya's 15 years ago all had one... Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted January 7, 2008 Author Share Posted January 7, 2008 Getting fed up with this Firestorm. Me and my buddy bought the same cars the same day, his is running fine, mine not at all. Bogging, stalling, bogging again, then revving like crazy... , bogging again, stalling, bogging, revving... etc Goes on like that all day! Have tried everything, the damn thing makes me crazy!! Today I just wanted to crush it under my boots!! :ranting: Any ideas someone? I still have the impression it's short on fuel sometimes, but all tubes seem to be fine. Maybe I should replace the tubing completely? Apart from that today: -clutch came loose (and saw the threadshaft of it is a little bent) -I lost an exhaust bolt... Goddamn it's a brand new car, it is at it's 10th tank only, mostly on tarmac! Anyway, here's a video of it running, image quality sucks (was filmed with mobile) but you should be able to see and hear what I mean really... I edited the worst parts together! my Firestorm video and let the nitro-experts stand up please! Quote Link to comment Share on other sites More sharing options...
e-vanS Posted January 7, 2008 Share Posted January 7, 2008 sorry mate, wish i could help you - but i'm not experienced enough... i have the same car, got it for xmas, been fantastic to me. have you tried going right back to the start, everything flush, and just start over again? i only run mine on 16% nitro, it's cheaper and i'm skint ohh by the way, what does the pressure pipe from the exhaust to the tank actually do???? been wondering for a while now... Quote Link to comment Share on other sites More sharing options...
HappyLad Posted January 7, 2008 Share Posted January 7, 2008 ohh by the way, what does the pressure pipe from the exhaust to the tank actually do???? been wondering for a while now... The exhaust pressurises the fuel tank - so pushing fuel up to the carb Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted January 7, 2008 Author Share Posted January 7, 2008 (edited) sorry mate, wish i could help you - but i'm not experienced enough... i have the same car, got it for xmas, been fantastic to me. have you tried going right back to the start, everything flush, and just start over again? i only run mine on 16% nitro, it's cheaper and i'm skint ohh by the way, what does the pressure pipe from the exhaust to the tank actually do???? been wondering for a while now... Yeah I have tried that like a zillion times!! Everything flush! But it keeps bogging all the time (and stalling sometimes). The hard thing for me to get is that its behaviour changes continuously... First it's running not bad (not perfect though) for like 2 min, then the troubles (like in the vid) start to happen for a minute, then it runs acceptable, then again bogging... pfff the damn thing is making me crazy, especially cause my friends one is just awesome on factory settings! He hasn't touched any needles yet! Any tuning on mine makes it even worse! I'm under the impression, it's running better in the beginning, when it's not hot yet. Then it starts to run worse gradually (that's like after 4-5 minutes)... I measured the temp in the middle of the cooling head, it was 105 °C, that's fine isn't it? The pressure pipes provides the fuel pressure to the carb as exhaust gasses provide the pressure. Edited January 8, 2008 by Joe Tosh Quote Link to comment Share on other sites More sharing options...
HappyLad Posted January 8, 2008 Share Posted January 8, 2008 Watched the vid and can see your problem. The motor seems to be ok one moment then terribly groggy the next. I suppose that once you have a temp gun you'll be able to check the engine temp and see if it is the cold which is causing problems, but the vid makes me think it may be something else..... See that you have fitted a rotostart and you also say that you have rotated the fuel inlet connector. I'm wondering if you may have introduced an air leak into the motor. An air leak will allow more air into the engine than is being drawn through the carb - this will lean the engine and make it rev high. If the leak is opening and closing then maybe this could be causing the problems in your vid?? I'd be tempted to take the motor out, strip it down and rebuild sealing all the joints with instant gasket. There is a how-to on sealing a motor on Savage Central, but you'll have to register to see it ==> clicky Quote Link to comment Share on other sites More sharing options...
smithy1135 Posted January 8, 2008 Share Posted January 8, 2008 Sounds like you have a leak somewhere. Let it heat up and then spray wd40 around parts that could possibly leak and listen for a change in revs. Quote Link to comment Share on other sites More sharing options...
HappyLad Posted January 8, 2008 Share Posted January 8, 2008 Sounds like you have a leak somewhere. Let it heat up and then spray wd40 around parts that could possibly leak and listen for a change in revs. Especially round the backplate where you've fitted the rotostart and then round the carb....... Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted January 8, 2008 Author Share Posted January 8, 2008 Watched the vid and can see your problem. The motor seems to be ok one moment then terribly groggy the next. I suppose that once you have a temp gun you'll be able to check the engine temp and see if it is the cold which is causing problems, but the vid makes me think it may be something else..... See that you have fitted a rotostart and you also say that you have rotated the fuel inlet connector. I'm wondering if you may have introduced an air leak into the motor. An air leak will allow more air into the engine than is being drawn through the carb - this will lean the engine and make it rev high. If the leak is opening and closing then maybe this could be causing the problems in your vid?? I'd be tempted to take the motor out, strip it down and rebuild sealing all the joints with instant gasket. There is a how-to on sealing a motor on Savage Central, but you'll have to register to see it ==> clicky OK, sounds like we're getting somewhere Yes i did rotate the fuel inlet, but that's only loosening a 7mm bolt, rotate it 90 degrees and retighten it, there's no gasket there I suppose? But good thinking, will check that. Now, it has never ran fine after break-in, I almost immediately got into problems. Can't remember though when exactly I did rotate that thing... Rebuilding the engine sounds a little harsh for a 3-weeks old car, doesn't it? Thanks for the howto-link though. If nothing works, I might do that. Air leak, hmm yeah thought about that, to me it sounded more like a fuel shortage... but you could be right... Quote Link to comment Share on other sites More sharing options...
smithy1135 Posted January 8, 2008 Share Posted January 8, 2008 OK, sounds like we're getting somewhere Yes i did rotate the fuel inlet, but that's only loosening a 7mm bolt, rotate it 90 degrees and retighten it, there's no gasket there I suppose? But good thinking, will check that. Now, it has never ran fine after break-in, I almost immediately got into problems. Can't remember though when exactly I did rotate that thing... Rebuilding the engine sounds a little harsh for a 3-weeks old car, doesn't it? Thanks for the howto-link though. If nothing works, I might do that. Air leak, hmm yeah thought about that, to me it sounded more like a fuel shortage... but you could be right... An air leak could cause it to run lean (too much air, not enough fuel) as it lets in air when the leak opens, this making it near impossible to tune. Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted January 8, 2008 Author Share Posted January 8, 2008 Sounds like you have a leak somewhere. Let it heat up and then spray wd40 around parts that could possibly leak and listen for a change in revs. You mean, while running on idle? What would the WD40 exactly do? Does it combust? In that case brake cleaner might be better, no? It's more volatile thus more combustable I would say? Or do you mean someting else? Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted January 8, 2008 Author Share Posted January 8, 2008 Especially round the backplate where you've fitted the rotostart and then round the carb....... Ok, will do. Then again the rotostart isn't sealed or anything like that, so isn't the stock-pull starter, I think the engine is "close" over there. I installed the roto, cause I trashed the pull starter during my endless restarting... Guessed it would be easier with a cordless drill. And it is! Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted January 8, 2008 Author Share Posted January 8, 2008 An air leak could cause it to run lean (too much air, not enough fuel) as it lets in air when the leak opens, this making it near impossible to tune. Yes indeed... Guess it's the same symptoms as too less fuel. Thanks for thinking with me guys! Quote Link to comment Share on other sites More sharing options...
HappyLad Posted January 8, 2008 Share Posted January 8, 2008 (edited) You mean, while running on idle? What would the WD40 exactly do? Does it combust? In that case brake cleaner might be better, no? It's more volatile thus more combustable I would say? Or do you mean someting else? yes - have the engine running and give a quick spray of WD40 onto the suspect areas - WD40 will burn, but it will also temporarily seal any leak that is sucking air into the motor. Its this air sealing property we are interested in Please don't use brake cleaner :( :( Edited January 8, 2008 by HappyLad Quote Link to comment Share on other sites More sharing options...
HappyLad Posted January 8, 2008 Share Posted January 8, 2008 (edited) Ok, will do. Then again the rotostart isn't sealed or anything like that, so isn't the stock-pull starter, I think the engine is "close" over there. I installed the roto, cause I trashed the pull starter during my endless restarting... Guessed it would be easier with a cordless drill. And it is! you may have disturbed the seal when you fitted the rotostart - the engine back plate is an obvious place for an air leak simple because of the size of the seal. its the biggest on the motor! Edit: Oh - and sort out the exhaust as having a bolt missing won't help. Make sur ethe exhaust is seated correctly with either a HPI gasket, or some instant gasket material. See if you can get a longer bolt and put a threadlock nut on the other end to secure the exhaust as the HPI bolts have a tendency to undo themselves through vibration. Edited January 8, 2008 by HappyLad Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted January 8, 2008 Author Share Posted January 8, 2008 yes - have the engine running and give a quick spray of WD40 onto the suspect areas - WD40 will burn, but it will also temporarily seal any leak that is sucking air into the motor Please don't use brake cleaner :( :( Ok, like that! I do understand why no brake cleaner then! (it is a little trick I've used once on my motorbikes) Could I have "blown" a leak into something using air compressor to clean it? Stupid question maybe, but I'm just thinking out loud... I do tend to be cautious with the aircleaning though, so that would surprise me... Quote Link to comment Share on other sites More sharing options...
HappyLad Posted January 8, 2008 Share Posted January 8, 2008 Could I have "blown" a leak into something using air compressor to clean it? Stupid question maybe, but I'm just thinking out loud... I do tend to be cautious with the aircleaning though, so that would surprise me... doubt you've damaged anything cleaning with compressed air. Quote Link to comment Share on other sites More sharing options...
Joe Tosh Posted January 8, 2008 Author Share Posted January 8, 2008 (edited) you may have disturbed the seal when you fitted the rotostart - the engine back plate is an obvious place for an air leak simple because of the size of the seal. its the biggest on the motor! Edit: Oh - and sort out the exhaust as having a bolt missing won't help. Make sur ethe exhaust is seated correctly with either a HPI gasket, or some instant gasket material. See if you can get a longer bolt and put a threadlock nut on the other end to secure the exhaust as the HPI bolts have a tendency to undo themselves through vibration. Well no, there is NO seal between pull or rotostart and the backplate, just the one way bearing that's it. And I only fitted the roto before my last afternoon trying to run it, had the same problems before already. EDIT made a quick pic with my mobile: Yeah I did refit the engine bolt, will order a new HPI gasket though... Good advice on the longer bolt with the threadlock nut! One more debatable question : I did lose the engine bolt on my last run. Could it possibly be, this bolt was loose from the beginning and that the air leak was caused by this loose bolt since the beginning? Can a nitro engine suck in leaked air on the exhaust side? Edited January 8, 2008 by Joe Tosh Quote Link to comment Share on other sites More sharing options...
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