rotax cold start problems

[happydays]

has anyone had problems with cold starting a rotax 912A?? using the recommended approach - close throttle, electric pump on, full choke - does not work - engin does not start and kicks back. This problem has only started with the recent cold weather. Prevoiusly cold starts using the above proceedure worked ok.

[John Price]

Hi Happydays,

Try jump starting using another battery in parallel. Low voltage can cause the starter to under rotate the engine causing the problem. Or leave the existing battery on charge for a bit to boost its voltage and current.

Our 912 can be difficult if the battery needs a charge especially when cold.

Its a simple thing to start with prior to major investigation works.

John.

[G-TERN]

Hi, there's many "individual personal techniques" floating around for cold starting. One which I have tried and (touchwood) seems to improves things is this:
It seems you don't want it to fire too early so get the starter spinning well before it is 'allowed' to fire:
-run the electric pump for a few seconds then off again
-throttle closed or just cracked open a tiny bit
-ignition switches ON
-choke OFF
-Operate starter and after a couple of seconds when it is spinning well pull the choke ON. It 'should' fire up straightaway!

Advantage of this is that it will fire when the choke gets to the right setting, ie a cold start on a hot day might not need totally full choke - it will start when you have moved the choke out far enough - which may or may not be full!
Might be worth a try - good luck!
Ps. Totally agree with above - the battery definitely needs to be in good shape, well charged or a new one or a jump start. The battery and engine block ground connections might be worth checking if they're old.

[mikehallam]

Excellent advice and wot=rthe remembering.

BUT, Not forgetting the slow death syndrome well reported on the BMAA forum of the Ducati black boxes. They run well once started but are too weak when at starter rpm's.

[ See also mention in Jan '15 RansMail for a solution of sorts.]

mike hallam.

[Joseph Cullen]

For what it's worth, after balancing the carbs on my 912ULS I found that the idle was rather on the slow side and the throttle needed to be opened just a touch to get it to start, otherwise it would "kick back" and not start. It only requires a very slight touch to make the difference between firing immediately or not going at all.

[John Price]

Hi Andrew,

How did you get on?

John.