View Full Version : Who's had a hot start?
EdgeCrusher
03-10-2008, 10:16 PM
After spending some time watching RC videos and getting my 90's ready for the season i am still amazed to see people free hand start these machines? I remember my fist hot start and WOW! fresh change of clothes was in order. I seem to find myself going through a checklist now before i hit that stater. I gained EXTREME respect for the ability these machines can pack real fast.
Share you experience and any steps you take to avoid this nasty little surprise.
iflynething
03-17-2008, 09:36 PM
I remember I did that one time and it scared me $H!Tless.
The thing was it was of course my fault. I had just got done putting the engine back together after a thorough cleaning and forgot to put the other screw to hold down the carb. This was only on a Raptor 30 so it wasn't that bad. What I had was alot of fuel (after priming) and alot of air mixing together (becuase of that dang screw missing) and it just started crazy fast. I didn't know what to do.
I didn't know that was it until after about 4 hot starts. I just was like, crap, I'll just take the engine back apart and find what's going on here. I found it really fast.
~Michael~
JimLerch
03-18-2008, 11:33 AM
I was helping a buddy was a newly assembled heli. We inadvertently got the idle mark and the WOT mark on the carb backwards in our setup. That first start was exciting!
Took maybe half a second for me to reach over and pinch the fuel line, but that was one LONG half a second! Other than breaking in his clutch liner rather forcefully, all was well as held the heli while I pinched the fuel line.
Might have been really ugly if he had been by himself! He had one hand holding a blade grip, and the other holding the starter. He really could not let go of either to pinch the fuel line off with the motor running wide open...
WillJames
03-19-2008, 12:01 PM
I was helping a buddy was a newly assembled heli. We inadvertently got the idle mark and the WOT mark on the carb backwards in our setup. That first start was exciting!
Took maybe half a second for me to reach over and pinch the fuel line, but that was one LONG half a second! Other than breaking in his clutch liner rather forcefully, all was well as held the heli while I pinched the fuel line.
Might have been really ugly if he had been by himself! He had one hand holding a blade grip, and the other holding the starter. He really could not let go of either to pinch the fuel line off with the motor running wide open...
If there is a rubber exhaust diverter on the muffler, pinching it closed kills the motor a good bit faster than cutting the fuel. Also if you pinch the muffler diverter it makes the engine rich. If you pinch the fuel line it makes the motor lean out before it dies.
I am not sure of anybody I know who flys glow (Before model match) who has not had a hot start at one time or another. Grab the head and hold firmly before starting is your safest start technique.
dogfart
03-19-2008, 01:12 PM
When I first built my Trex 600, it was on the dining room table. I had been adjusting pitch curves and made the mistake of turning off the radio before unplugging the heli battery (with BEC to the receiver). I quickly learned WHY the instructions say to always turn off the radio LAST. As the bird spooled up to full throttle, I called out to my girlfriend who was in the next room "something very bad is happening here!" Everything on the table that wasn't nailed down got blown across the room. A few papers went through the main blades and came out shredded. I was picturing the thing crashing through the window, or much worse, coming right at me. It was very lucky the collective was at zero degrees pitch. The bird just sat there perfectly still for several seconds until I tried turning the radio back on. That did the trick, and the excitement was over. At least there was no great harm done. Now, whenever I need to work on her with the battery plugged in I disable the motor. Plus, I will ALWAYS remember to turn off the radio LAST.
iflynething
03-19-2008, 09:23 PM
[QUOTE=dogfart;595336]...... Now, whenever I need to work on her with the battery plugged in I disable the motor. \QUOTE]
I like working on her too without the battery plugged up. You get into alot of trouble
~Michael~
mporlier
03-19-2008, 09:39 PM
When I first built my Trex 600, it was on the dining room table. I had been adjusting pitch curves and made the mistake of turning off the radio before unplugging the heli battery (with BEC to the receiver). I quickly learned WHY the instructions say to always turn off the radio LAST. As the bird spooled up to full throttle, I called out to my girlfriend who was in the next room "something very bad is happening here!" Everything on the table that wasn't nailed down got blown across the room. A few papers went through the main blades and came out shredded. I was picturing the thing crashing through the window, or much worse, coming right at me. It was very lucky the collective was at zero degrees pitch. The bird just sat there perfectly still for several seconds until I tried turning the radio back on. That did the trick, and the excitement was over. At least there was no great harm done. Now, whenever I need to work on her with the battery plugged in I disable the motor. Plus, I will ALWAYS remember to turn off the radio LAST.
Wow... Never plug the motor when doing adjustments. This is what I like about nitro, then do not spool-up on you! I prefer a hot start to what happened to you. And yes, I did have hot starts. All my fault.
JaggedEdge
03-20-2008, 07:22 PM
Newb here.
While in ST1 I landed using throttle hold I left the tx at mid stick and turned off THold.
Heli spun up into the air did a 180 hovering while facing me. lol. I'm a newb and have NO nose in hover experience. THold and let it land itself. Hope I never do that again.
-ronin-
03-21-2008, 12:54 AM
gentlemen, I have a solution! after many long hours and thousands-of-dollars of R&D, I have developed an immediate cure for the unexpected hotstart. this new method will make the fear of hotstarts a thing of the past, and will also make you the life of the party. 100% satisfaction guaranteed!
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http://img177.imageshack.us/img177/2860/mastahblastahvp5.jpg (http://imageshack.us)
:D
man, you guys had me cracking up with your stories. I could just visualize all of them in my mind's eye. thanks so much for sharing and keep it up!
JimLerch
03-21-2008, 08:49 AM
If there is a rubber exhaust diverter on the muffler, pinching it closed kills the motor a good bit faster than cutting the fuel. Also if you pinch the muffler diverter it makes the engine rich. If you pinch the fuel line it makes the motor lean out before it dies.
Now there is a tidbit of info that could easily be over looked as unimportant! Having just replaced a piston and sleeve from running during suspected lean conditions, I have a new appreciation for running the motor a little on the fat side!
ClayK
03-21-2008, 12:16 PM
Now there is a tidbit of info that could easily be over looked as unimportant! Having just replaced a piston and sleeve from running during suspected lean conditions, I have a new appreciation for running the motor a little on the fat side!
Muffler diverter pinch method, fuel line pull, fuel line pinch method. All will work. Muffler diverter works pretty easy since it's large. Even if you hold the head (highly recommended) when you start, it's going to be tough. I had a hot start a long time ago, the head and links wrapped around one hand (pinning/trapping it) and it took everything I had to reach just a fuel line with the other hand.
Even with model match, you can still have a hot start. Throttle curves or reversed servo setup can do it. I know people that have copied a model and tweaked with the setup and then flew on the wrong model. It's still possible. Nothing, and I mean nothing, replaces good startup procedures that keep safety in mind. Never rely on technology to "shield" you. I equate this to ABS and traction control systems in cars. They exist in all cars now a days but nothing replaces proper training on how to brake properly, driving in rain/slippery conditions, hydroplane immediate reaction and how to steer a skid.
Rogan
03-21-2008, 06:45 PM
If there is a rubber exhaust diverter on the muffler, pinching it closed kills the motor a good bit faster than cutting the fuel. Also if you pinch the muffler diverter it makes the engine rich. If you pinch the fuel line it makes the motor lean out before it dies.
That's a very good tip. It takes longer than you'd like to kill the motor by pinching the fuel line when you're in that situation. :|
A hot start on a helly isn't as bad as all that - if you've got your hand firmly holding the head, as you should have when starting her up. One hand on the head and one foot on the skids means the clutch will slip (and start to burn) even when the throttle is at 100%.
My only (so far) hot start was from flipping the linkage to the engine. :roll:
R1R 7humbs
03-22-2008, 02:54 AM
I had a hot start early on. There was a miscommunication between me and my brother and I thought he was turning it over to blow out excess fuel. Instead he had put the plug back in and hit the ignite button and I had the throttle at wide open. Fortunately the blade was already up against his arm so as soon as the engine started it screamed for a second before stalling. I think we both said what the f&*^ how did we not know what the other was doing - 100 times. :arggg:
\ had a hot start with a 90 soon after getting it, now I always start with one hand on the head and if a hand is not on the head, then i have thottle hold on. when moving to the tarmac or coming back to the pits you can hit the throttle stick by mistake.
When I have the engine out or run the engine up the first time after doing any kind of changes to tx or rx etc. I always start with out the blades on.