912ULS Cold Starting Problem
in General Tech Discussion
12 years ago
Hi, I have a problem starting my 912 ULS from cold. On the first start of the day (summer or winter) it fires immediately but commences running with a horrible violent shaking/ grinding as if its running on just one cylinder! This continues for about 4 to 5 seconds before bursting into completely normal running which is fine thereafter. It only does it from absolute cold on the first start of the day. Once started, operation is sewing machine smooth thereafter in all stages of ground and flight operation. Any other start throughout the day is completely normal. It does seem to be a big problem as recently I found both rear exhaust down pipes to have large cracks 3/4 of the way around in exactly the same place each side. The exhaust has only done 25 hours from new as part of my new engine installation. I can only think the cracks have formed due to this extreme shaking.
I bought the engine second hand about 18 months ago. It is a 912ULS, without slipper clutch, made in 2002 with 220 hours. Although it has the small starter motor I have an excellent and fully charged battery with very short cable runs and I am confident of all the electrical connections. The carbs are well sync'd and I have the warm idle set to 1700 Rpm. My cold start technique is full choke and throttle fully closed. Its a bit difficult to trouble shoot as it only does it once a day! Any help or advice would be very much appreciated.
I bought the engine second hand about 18 months ago. It is a 912ULS, without slipper clutch, made in 2002 with 220 hours. Although it has the small starter motor I have an excellent and fully charged battery with very short cable runs and I am confident of all the electrical connections. The carbs are well sync'd and I have the warm idle set to 1700 Rpm. My cold start technique is full choke and throttle fully closed. Its a bit difficult to trouble shoot as it only does it once a day! Any help or advice would be very much appreciated.
