In a message dated 6/5/2003 12:11:03 AM Pacific Standard Time,
nigelcharles@tiscali.co.uk writes:
> This sounds a little strange. When the mag drop is excessive you would
> expect to find a cylinder with low rather than high EGT. I fitted 4 EGT
> senders so that I could identify the rogue cylinder in the event of a failed
> mag drop check. The only thing I can think of is that the rise indicates
> that those cylinders are OK and working harder to overcome poor ignition in
> one or both the other cylinders.
>
####The way I understand it is the single ignition causes a single flame
front, which delays the peak temperature and shortens the cooling time in the
cylinder, thus ejecting hotter gas into the exhaust. That is a normal thing for
Lycoming and continentals. I see about a 70 degree rise in my IK2000 on the twin
Comanche. All the cylinders rise in the Rotax, but two plugs rise about 150
degrees. I called Rotax again this morning and am going to check the resistance
of the plug wires and caps..........
> Is the mag drop as bad when the engine is not fully warmed up and without
> the top cowl on? If so I would suggest that it is unlikely to be caused by
> overheated electronics..
>
#######It seems worse when the engine is warmed up, but the cowl is off and
it still is bad when the engine is cool.......
> Your problem doesn't sound a typical Rotax problem. As for Lycomings, in
> the
> past I have known of two cases which had difficult to solve mag drop
> problems so they are not exempt.
>
########Grass is always greener, eh? I am sure I will be calmed down once I
solve this problem. After all, it did run fine for 65 hours!
Thanks,
Dave
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