View Full Version : And then it went quiet......
jeznewsome
09-15-2007, 05:19 PM
Been flying the Rappy today and whilst inverted at about 20-30 feet the noise stopped.....EEEEEEEeeeeeek.
Managed to get the thing upright and following a 'hard' landing I seem to have got away with it lighter than I might have expected:-
- Bent Flybar
- minor linkage tweaking required
Having taken it back to the pits a quick check with the glow driver showed that the plug was open circuit? Quick change of the glow plug and the engine started fine.
So, for those of you with more nitro experience than me ...... would the failed electrical continuity of the glow plug stop the wire from retaining heat in an already running (for about 5 mins of general throwing about) engine? The header tank was full on landing (and main tank was 1/2 full) so I doubt fuel starvation was a problem).
Really impressed that the Rappy is still in good shape and very pleased to have got away with it but would like to know what caused the problem.
If the wire breaks in the glow plug the engine will stop
Mike SVOR
09-15-2007, 06:54 PM
If the wire breaks in the glow plug the engine will stop
not necessarily. As long as the wire keeps glowing, the engine will run. Same reason why it doesn't need electricity to the plug to stay running.
I'm not sure I quite understand the "eeeekkk" noise described. Did the engine sieze? did you try to turn the engine over right after that noise?
Might wana check your flywheel/clutch bolt to see if it came lose and jammed against the starter shaft.
invertmast
09-15-2007, 07:58 PM
not necessarily. As long as the wire keeps glowing, the engine will run. Same reason why it doesn't need electricity to the plug to stay running.
I'm not sure I quite understand the "eeeekkk" noise described. Did the engine sieze? did you try to turn the engine over right after that noise?
Might wana check your flywheel/clutch bolt to see if it came lose and jammed against the starter shaft.
i think thats the noise he made when it quit hehe
jeznewsome
09-16-2007, 02:51 AM
Eeeeekk certainly was the noise that I made!
Interesting responses......my immediate thought was that the broken glow would stop the engine but then couldn't work out why the broken electical continuity would stop the wire glowing once the engine was running. So I now have one for and one against!
I did turn the engine over as soon as I could after landing to check that it hadn't seized and it was fine. Also once back in the pits, with a new glow plug it started fine and ran cleanly at idle.
Looks like I will need to temper my enthusiasm on the next flight an take it gently for a tank full to check everything out and may richen it up a little to ensure that it ain't overheating
invertmast
09-16-2007, 11:06 AM
i've had plug fillaments in flight break and the engine still run, then i've had them break while on the ground carrying the chopper out and it quit.. kinda a hit and miss thing and one reason i replace all my plugs every 15-20 flights.
Mike SVOR
09-16-2007, 12:15 PM
i've had plug fillaments in flight break and the engine still run, then i've had them break while on the ground carrying the chopper out and it quit.. kinda a hit and miss thing and one reason i replace all my plugs every 15-20 flights.
yea true. It's hit and miss I guess.
btw, i'm still on my first glow plug and on my 5th gallon of fuel.
invertmast
09-16-2007, 06:58 PM
i consider glow plugs cheap insurance.... i'd rather spend $4 every couple of flights for the piece of mnd
oldskool
09-16-2007, 10:37 PM
i consider glow plugs cheap insurance.... i'd rather spend $4 every couple of flights for the piece of mnd
every couple of flights?!? Man I wish I flew with you... I'd just fly your throwaways! Once per case is prob sufficient IMHO.