Re: older 912 ul heating up
Not sure because I just fly mine and have never had to adjust but "drop down the needle" wouldn't that make it leaner as less gas is being allowed in the carb. Not sure on the 912 but I know that is how the 582 would work.
Re: older 912 ul heating up
Nope I drop the clip down that takes needle up and makes richer. I’m looking to see if I can maybe change the timing?
Re: older 912 ul heating up
Have you checked the entire coolant system including radiator for free flow?
Re: older 912 ul heating up
How about the sender or gauge?
Re: older 912 ul heating up
Are you using 50/50 antifreeze/water or Evans water less coolant? There is around 25F difference between them in coolant temps.
Do you have all cylinder's exhausts monitored for egt ?
Carbs out of sync can cause different egt readings on different cylinders .
High egts can mean inefficient burn in the heads. Proper plugs? gapped at what?
Prop pitch can affect heating, over pitched and you will generate heat. lugging the engine will do this also.
Did you try increasing rpms ? to 5300- 5500, sometimes this will make the engine run cooler.
Re: older 912 ul heating up
Ok guys I have not flushed the coolant system good idea will do only have two egts one in the front and one in the back other side of motor. Carbs are synced right on the money and by the way brand new carbs not old ones also brand new spark plugs, have not try to run high RPM . I get if the coolant is a problem but would that send the EGTs through the roof again has anyone gone fatter on the main jet ?? I have 158 jet size and a 2nd through would be to much exhaust restriction could cause this also ?? Again hair pulling shi”” thanks for the help guys anything more you guys come up with let me know.
Re: older 912 ul heating up
Oldfox,
Just a thought. Many times when I have done engine diagnosis (not necessarily aircraft engines) especially when a symptom can have many causes such as this puzzling situation your are dealing with, I have found it useful to go back and check cylinder health first....meaning compression - reason being that no amount of work on the ignition or fuel systems will dispatch a problem if there is a mechanical problem such as an exhaust valve developing a leak.
A cylinder problem can translate into high EGT or high CHT due to lack of cylinder efficiency. Ruling this out could help reduce the number of things you would want to consider.
Again, just a thought.
Re: older 912 ul heating up
Before all this started, what were the original readings?
Re: older 912 ul heating up
Quote:
Originally Posted by
oldfox
ok guys need some help just got the old bird back in the air flew great hands free but as I made the 4th lap around patch EGT (1530F) CHT (251F) stared to get on the high side oil temp was good 185 F...
A couple things to consider, Float level, carb vent line location. Check your
Egt gauge and sender. Do you have an oil cooler? Do you have a heater installed?
Make sure you not more than 50/50 on you antifreeze mix. Do you have a thermostat installed.
Drain your cooling system and refill using a vacuum refill system. Very important if you have a heater and thermostat.
I have a speedster with an early 912. I’m at 160 on the mains but I also have the zipper big bore kit.