Having a few issues with my lycoming 200av

[Omar2525]

This my first thread on here i been operating airboats for only 3 years just bought my first one a month ago it's a lycoming 200 aka 360 with 480 jugs i been having a few issues with it first the motor doesn't like to idle when cold which im thinking the carb needs a lil tuning after reaching temp 180 the oil pressure is 18-20 psi at 500 rpm idle, running 2200 rpms it's 50-55 then at cold idle it's 55-60 at 600-700 rpms goes to 80 at 1000 idk if these pressures are normal. My biggest issue is that it doesn't like to start when it gets hot 180-185 max but it's not always consistent but lately it's been more common i shut the mags off wait 10 mins try to start it nothing wait 30-45 mins it starts

 

[Omar2525]

Just adding on it turns over fine just doesn't act like it even tries to fire up mags have been rebuilt less than a year ago and if i shut one off while idling it keeps running no matter which mag i shut off

 

[BobBrack]

Do you have spacer plates under the cylinders? I ask because if you don't you may have very high compression if it is truly a 200 bottom end with 480 cylinders.

 

[John Fenner]

Just adding on it turns over fine just doesn't act like it even tries to fire up mags have been rebuilt less than a year ago and if i shut one off while idling it keeps running no matter which mag i shut off

And if you shut both mags off?
You mentioned both mags rebuilt, both should be timed to 20° not 25°
As Bob stated, not knowing the internals of this engine, compression ratio, kinda shooting blind here.

 

[Omar2525]

Do you have spacer plates under the cylinders? I ask because if you don't you may have very high compression if it is truly a 200 bottom end with 480 cylinders.

So i had it looked at by a couple other airboat buddies seems like a 360 wide deck with 540 av cylinders no spacers under cylinders