Primarily for general aviation discussion, but other aviation topics are also welcome.
#1672909
I always had this issue with Robin but it seems to have gone worse during the winter. I take out the club's DR400, top it up with fuel and wish to fly afar, and the engine doesn't start. Get it back in the Hangar after many failed attempts and I have wasted 1.5 hour for nothing.

Other members have perhaps learned the trick, which has still been elusive to me. I follow the 'practical' instructions, fuel pump on, mixture rich, prime the throttle eight times, keep the throttle knob slightly in, magnetos to both and ignition. The engine splutters after pushing the ignition for another 20-30 seconds. While engine making feeble sound I try to push throttle once or twice to get more fuel in, but mostly it fails to start.

The POH says to wait a minute before retrying. Hereon, I am not sure how to handle further attempts. I should perhaps not pump throttle too often. I can't sense if I have flooded the engine and need to attempt try firing with mixture lean.

Does it sound familiar to you? How did you get around it? Mind you, it is a club plane. So I don't expect that they'll change the battery or something if others have learned the trick and don't complain.
#1672919
I would urge you to seek help from your members pronto before you have a carb fire. If it works for them it should work for you. Be aware that asking for help on a forum like this will get you all sorts of theories , some may not be wise.
If your members can do it they should be able to show you how.
Lockhaven, T67M, AlanC and 3 others liked this
#1672920
I have no DR400 experience, but a checklist I've found on the web reads max 4 primes for a cold engine, and start on the left mag only. Many aircraft only have one impulse coupling, almost always on the left mag, and trying to start with both mags selected causes the fuel to be ignited before the piston reaches the top of the stroke. This effectively tries to start the engine turning backwards - obviously sub-optimal!

Have you talked this through with other pilots of this specific aircraft? Even two supposedly identical aircraft can have "quirks" that regular pilots get to know.

Edited for typos
Last edited by T67M on Thu Feb 07, 2019 11:29 pm, edited 1 time in total.
Lockhaven liked this
#1672921
Most induction fires are caused by throttle over priming and sometimes owners etc using wrong techniques. An aircraft engine that persistently wont start using the flight manual or POH techniques has a maintenance problem that should be addressed by a suitable licensed engineer. Poor starting can be the first sign of other problems that need investigation.
#1672922
To be completely honest, I didn't know about carb fire before I started searching about the topic. That has definitely got me worried trying on my own the next time.

The POH actually says to pump four times and use the left magneto only for start, but no one at the club follows this. I also read elsewhere that starting with left only mag is more relevant for smaller engines, not 180 HP that I fly.
#1672924
statppl wrote:To be completely honest, I didn't know about carb fire before I started searching about the topic. That has definitely got me worried trying on my own the next time.

The POH actually says to pump four times and use the left magneto only for start, but no one at the club follows this. I also read elsewhere that starting with left only mag is more relevant for smaller engines, not 180 HP that I fly.


@statppl

Can I ask are you pumping the throttle 4 times or using the primer 4 times, there is a big difference.
#1672931
statppl wrote:To be completely honest, I didn't know about carb fire before I started searching about the topic. That has definitely got me worried trying on my own the next time.

The POH actually says to pump four times and use the left magneto only for start, but no one at the club follows this. I also read elsewhere that starting with left only mag is more relevant for smaller engines, not 180 HP that I fly.


Ouch!That really is basic PPL knowledge that you should have been taught during your PPL! Plus also how to deal with an induction fire by turning the engine over.

Problem with throttle priming is over priming will mostly lead to fuel dripping out the bottom of the carb. If you think you have over primed get out and have a look before you attempt restart.
T67M liked this
#1672960
Don’t believe the DR400 was fitted with a primer, it relies on the accelerator pump in the carb instead. Probably little need for a primer in the slightly warmer climate of France??

Would suggest stuffing a 2kW hairdryer into the cowling intake for 15mins or so while you do your walk round. Bet it will go first turn of the key after following the POH starting procedure after that.

Don’t forget to remove it before flight though!
#1672964
The Kissimmee Bum wrote:Don’t believe the DR400 was fitted with a primer, it relies on the accelerator pump in the carb instead. Probably little need for a primer in the slightly warmer climate of France??

Would suggest stuffing a 2kW hairdryer into the cowling intake for 15mins or so while you do your walk round. Bet it will go first turn of the key after following the POH starting procedure after that.

Don’t forget to remove it before flight though!


Or in case you havnt got mains electricity to hand, why not start a bonfire underneath the aircraft?
#1672977
Get your maintenance company to check out the carburettor, I have seen lately several Marvel Schebler MA4-5 carburettors that have had problems the the accelerator pump. Only a very small amount of fuel was being discharged when the throttle was pumped. The problem laid with the internal check valves and pump plunger.
Harry Brown, T67M liked this
#1672979
Harry Brown wrote:
Or in case you havnt got mains electricity to hand, why not start a bonfire underneath the aircraft?


If that’s what turns you on?

If, on the other hand you wish to start a chilly engine with little effort and assuming that you have mains or generator derived electricity, the hairdryer will do the trick.

The OP mentions it is a club aircraft so assume it is in a hangar at an airfield and not knee deep in cow excrement in some frosty field? It is after all a wood and fabric aircraft so presumably hangared.