Rotax throttle settings

[Brian]

Did a test this arvo for you. 912ULS (100HP)Wide open throttle. It absolutely, most definitely starts!!!!! Almost instant acceleration . Pretty startling sitting in the machine. Would NOT want to be standing anywhere near it.The carby"s are set up so that with any throttle on at all you cannot engage the choke. But, with the choke already on you can advance the throttle to full noise. Did not think it would be too clever to try to start it in this state, so can"t help you with that particular scenario.For my two bob...Failing to full noise may not be the safest option on the ground, but I would not have it any other way for a machine doing station flying.MilesThanks Miles for doing that test, I thought that nearly all engines will start with WOT.Personally, I would rather in the event of a cable break that the engine went to idle and for those pilots with limited expereince, I think panic would result in most cases, in fact, in a couple of fatatals, I reckon panic most certainly was a major cause of the accident.Anyone wondering about the discussion could next time out flying, go to WOT at a time thats most inconvenient to you and see how you fare. I have been told by a reliable source that a 912 /914 jammed at WOT may not be abnle to shut off by turning off the mags which could make for an intersting ride in most gyros, specially lightweight single place gyros !! In a MTO/ ELA / Xeneon type, I doubt you could get into too much trouble unless the air was rough. BTW, the bloke I talked to at Bert Floods said that they had had 912"s reving up to 14,000 revs so if you are going to wait till they chuck a rod or something, I think you will run out of fuel before that happens and if you decide to climb, how high might you get before you have to level out

[asra]

Thanks Miles, was that a cold engine start?

[birdy]

Wide open throttle. It absolutely, most definitely starts!!!!!Well, there y go, i stand corrected. :-XNever been able to get even the faintest f@rt outa a 912 or 914 if the throttle is more n slightly open. ???how high might you get before you have to level out Mate, id be reachn over me shoulder n ripn out plug leads n **** before i cracked 200".

[aussie_paul]

Wide open throttle. It absolutely, most definitely starts!!!!!Well, there y go, i stand corrected. :-XNever been able to get even the faintest f@rt outa a 912 or 914 if the throttle is more n slightly open. ???how high might you get before you have to level out Mate, id be reachn over me shoulder n ripn out plug leads n **** before i cracked 200". You would wait that long!!!!!Aussie Paul.

[Brian]

Wide open throttle. It absolutely, most definitely starts!!!!!how high might you get before you have to level out Mate, id be reachn over me shoulder n ripn out plug leads n **** before i cracked 200". Thats fine for you Birdy but how many pilots would remain as cool as you and even think of pulling the plug leads.??The average pilot is going to crap themselves with a WOT situation and to me the sealer in this discussion is that Rosco, who would have more gyros out there than most rigs the 912 to go to idle.

[aussie_paul]

Thats fine for you Birdy but how many pilots would remain as cool as you and even think of pulling the plug leads.??The average pilot is going to crap themselves with a WOT situation and to me the sealer in this discussion is that Rosco, who would have more gyros out there than most rigs the 912 to go to idle. I have to agree Brian.Aussie Paul.

[Des Garvin]

Well just from a ole hole digga just some of the problems of a 912 or 914 Rotax going to full noise on breaking a throttle cable.1. ya air speed is going to get up over most gyro"s VNE"s. So what happens as ya get faster? Ya rotor flattens in the cone and becomes rather twichy. Then you get the rotor stalling on the rear blade so the front blade rises until it takes out ya tail fin, and there goes your wind vane, and there goes ya life down hill very fast in circles.2. So ya have a lead sled gyro still not good as if the motor should start exceeding max normal revs those props are only good for 3000 od revs. So at what speed does the prop fling a blade and if it does you luck already being as it is, that blade will just as likely get the rotor and you will really get to know what rotor shake is untill you end up haveing a tumbling time. I will pass on this experiance thanks.So with it going to idle what do you have? just a engine out landing and if you are a good gyro pic you will land on that spot you just saw with no damage. May be.Cheers. Des Garvin.

[MilesW]

Thanks Miles, was that a cold engine start?That was a hot engine start. I have a near new engine so not real keen to start it at full noise dead cold with no oil pressure. Now that I know it starts hot WOT, I have no doubt it would do the same cold. Maybe someone with an about to expire one might like to try that.

[MilesW]

I have been told by a reliable source that a 912 /914 jammed at WOT may not be abnle to shut off by turning off the mags which could make for an intersting ride in most gyros, specially lightweight single place gyros !!That is very interesting. Could change the game a bit. Would definitely like to get that verified 100% one way or the other.My opinion/preference is based on the assumption I still had control over the situation through the kill switches (very conveniently located within fingertip reach of the throttle). I agree, that if that is not the case then it could escalate into a really bad situation really quick. A pucker factor of 10 I"d reckon

[asra]

Not sure about the ROTAX setup, but her is an easy fix for the Suby boys.These engines come with 2 throttle cable attachment points. Both points work separate of each other. 1 is for the throttle, and the other for the cruise control. So my suggestion is use the second attachment to connect a dash mounted second throttle. This needs to be the type were you pull it out and twist to lock (like a FW mixture control) GT Gyroplanes uses this type see pic as a park brake and rotor lock. This could now be used as your second emergency throttle and maybe also as a cruise throttle.Just my 2 cents ;DCheers SamL.................

[jeff b]

On the 914 if the mag switches won"t stop it at WOT, the 2 fuel pumps can be turned off. How long to shut down?

[Brian]

On the 914 if the mag switches won"t stop it at WOT, the 2 fuel pumps can be turned off. How long to shut down?Shouldnt take long at WOT although if the rotaxes are as economical as some suggest, could take half an hour or so

[tonydenton]

its good having a serious look at it all. but birdy saying above 200" he would **** and then pb sayiny are you going to wait that long was a crack up.

[Des Garvin]

Good old SU carbies what more does one need. As reliable as anything. Good choice Tony. Cheers Des Garvin.