Mat P Posted November 13, 2010 Share Posted November 13, 2010 (edited) hi, im new to this forum and nitro cars, so i would like to say hello everyone and i look forward to many positive conversations. right here we go! i realize its a bit cheeky to ask for help so soon but im eager to get out and use my car, its a thunder tiger 4x4 truck running a Force 15 engine its a 1/10 scale. the problem is it seized on the origional engine so i bought a new one (the force) and whilst trying to follow the running in precedure i got halfway thru idling a tank of nitro and it stopped, when i went to restart it was jammed solid, so i heated the head to free the piston and added some oil and it is now back to normal but what is causing this im at a loss and dont want to destroy another engine? thanks, any help is much appreciated (it seizes every time its running for more than a few minutes, carb settings are factory and all of the fuel system seems to be ok) Edited November 13, 2010 by x9moto Quote Link to comment Share on other sites More sharing options...
henzy190 Posted November 13, 2010 Share Posted November 13, 2010 I don't know much about it, but some new engines can be very tight and get stuck at TDC (top dead center.) heating up and oil etc. is a good way to sort it out though Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 13, 2010 Author Share Posted November 13, 2010 thanks, the other engine died the same way, the car was given to me secondhand and both engines have now seized at idle and the other engine was well run in but eventually lost compression due to seizing so many times. Quote Link to comment Share on other sites More sharing options...
chrisknights Posted November 13, 2010 Share Posted November 13, 2010 best bet is to heat it up with a hair dryer for 5minutes as its so tight , every new engine taks it time to breakin Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 13, 2010 Author Share Posted November 13, 2010 cheers, i have had some succsess by puting some oil in every few minutes, just a drip and it seems ok (hasnt seized after a tank) but im dubious about running it without the oil yet, as i think its leaning out on its own but the tank has no air leaks. Quote Link to comment Share on other sites More sharing options...
chrisknights Posted November 13, 2010 Share Posted November 13, 2010 is there oil coming out of the exshaust ( spitting ) as when new the needles are set to run rich so you should have enough oil in there Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 13, 2010 Author Share Posted November 13, 2010 (edited) not sure because it has a big exhaust on it and some kind of recurculation pipe, and it seems to be pumping the stray oil back into the tank Presumably to burn it off, so i dont see much spraying, it sounds rich though and choked when you rev it untill it clears out then it sounds normal. im no expert but i had a nitro car years ago when i was 16 but that one always worked so i never fiddled with it. (i have noticed that the idle starts to climb like its gonna run out of fuel but it has plenty in it, cant find a reason why it is doing this) Edited November 13, 2010 by x9moto Quote Link to comment Share on other sites More sharing options...
dazj10 Posted November 13, 2010 Share Posted November 13, 2010 i never do idle tanks for that very reason ,, i start engine and the turn throttle trim up ,,,,just a touch to keep it slightly above idle revs Quote Link to comment Share on other sites More sharing options...
mgtuser Posted November 13, 2010 Share Posted November 13, 2010 your engines havnt died mate, there just getting stuck at top dead centre ( TDC ) All new engines will do this as there is so much mechanical pinch when there new. by running them in, you help loosen this and makes the engine run properly and at its best. whenever your engine stops, make sure the piston is at BDC...bottom dead centre, at the bottom of the stroke. do this by turning the flywheel whilst the engine is still warm. you may have to use upto a gallon of fuel in total to break it in, so be patient. Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 13, 2010 Author Share Posted November 13, 2010 (edited) ok so you mean there is a natural tendancy for it to run lean if you let it idle for too long? (reply relates to previous post) so whilst im running these tanks of fuel through can i actually use the car at low speed or do these need to be at idle, also the first engine to seize was run in and the new engine is showing the same symptomes thats what worries me Edited November 13, 2010 by x9moto Quote Link to comment Share on other sites More sharing options...
HATZY Posted November 14, 2010 Share Posted November 14, 2010 the zhaust finds it hard to preassurise the tank at low revs so the occasional 1/4 throttle blip will help to keep fuel preassure up. after a couple of tanks at idle start running it around for a couple tanks at 1/4 throttle for 2 second blips then a couple tanks at 1/2 throttle 2 second blips then a couple tanks at 3/4 throttle 2 second blips then a couple tanks at full throttle 2 second blips then a few more tanks slowly tuning the performance. between each tank allow the engine to cool down for about 10-15 mins and make sure the piston is at bottom dead center to stop it siezing at tdc. if it gets stuck at tdc you can use a screwdriver to turn the flywheel freeing up the piston Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 14, 2010 Author Share Posted November 14, 2010 thanks, i will try tommorow and see how it goes:D Quote Link to comment Share on other sites More sharing options...
henzy190 Posted November 14, 2010 Share Posted November 14, 2010 a good tip I've heard is when idling tanks every now and again take the power upto full throttle slowly and then cut back to idle, apparently it cleans out excess oil from the engine. Quote Link to comment Share on other sites More sharing options...
carsonkev Posted November 14, 2010 Share Posted November 14, 2010 When your running tanks through with the car on a stand chances are the engines not getting hot enough the metal parts of the engine are supposed to swell ie get bigger this causing the engine to loosen and not get stuck Id run the car about at half throttle just so your getting heat in to the engine and it's not sticking at tdc kev Quote Link to comment Share on other sites More sharing options...
thevmister Posted November 14, 2010 Share Posted November 14, 2010 sounds to me like your fuel tank is not pressuring your fuel into your carb and it may be causing a lean condition and the engine seizes , i had a problem with a engine overheating while idling during a break in found a pin hole in the tank but it was half way down the tank at the seam so when it was full of fuel it would idle normally until i few minutes in it would suddenly rev a bit higher but more noticable than that the temperature would soar and a flame out would happen, i know a bit different to your prob but if this has happened to 2 engines , its time to look at whats common to both ie fuel tank Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 14, 2010 Author Share Posted November 14, 2010 i think i may have got to the bottom of it but still need a little advice on something..... i took it out today and it didnt seize when it was working the car at 1/4 throttle with the occasional blip, but after 20 mins it started not to rev and flame out (i think the post above about the parts not heating up was the reason for seizing) after this occured i checked the mixture and pressurised the tank with my mouth and pinched the end of the other pipe and no leak, i did the same with the engine and no leak, even turned up the fuel mix and no change. after hours of trying to start it, i realised that all my problems started when i bought a new bottle of fuel (because i thought the other stuff was off as the first engine ran crap but i later discovered the front bearing seal was trashed) and so i filled the tank up with the old fuel and it worked! no more lean run. so what do i do? try and get my money back for the other fuel or what could be wrong with it ( its the same grade as the first but a different make. yet again i am very greatfull for all your answers. Quote Link to comment Share on other sites More sharing options...
HATZY Posted November 14, 2010 Share Posted November 14, 2010 what are the 2 different fuels? Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 14, 2010 Author Share Posted November 14, 2010 one is Race Gen2 20%nitro the other is Opti Fuel 20%nitro, the first is the one that works the 2nd appears not to. Quote Link to comment Share on other sites More sharing options...
HATZY Posted November 14, 2010 Share Posted November 14, 2010 what plug where you usin? Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 14, 2010 Author Share Posted November 14, 2010 i have a number 8 (brand new) this is the one im using as recommended by engine manual and i also have a 3 but that doesnt appear to work, it glows but the engine wont start. Quote Link to comment Share on other sites More sharing options...
HATZY Posted November 14, 2010 Share Posted November 14, 2010 whats the engine size? Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 14, 2010 Author Share Posted November 14, 2010 its a force 15 i dont know the exact cc Quote Link to comment Share on other sites More sharing options...
HATZY Posted November 14, 2010 Share Posted November 14, 2010 try this plug Quote Link to comment Share on other sites More sharing options...
Mat P Posted November 14, 2010 Author Share Posted November 14, 2010 thanks, thats the place i got the last one, so what does the number mean? is that plug for running the new fuel or any? Quote Link to comment Share on other sites More sharing options...
HATZY Posted November 14, 2010 Share Posted November 14, 2010 their is no standard deffinition for the number as nearly all manufacturers use different numbers to mean different things, its the temp range you wanna be lookin at. im usin the lrp 5 in my engine which is a force .25 running 25% optifuel and its the best blug ive found for it without spendin loads. the lrp5 is medium cold and the lrp4 is medium which would be better suited to a .15 with 20%. you should be able to use it with any fuel though Quote Link to comment Share on other sites More sharing options...
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