older 912 ul heating up

[Xengineguy]

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.

[jrevens]

Could you provide some details, and possibly pictures, of using a vacuum refill system? Thanks!

[Xengineguy]

Could you provide some details, and possibly pictures, of using a vacuum refill system? Thanks!

The unit I’m currently using is the snap on Svtsrad272a. Check out Utube
They have some nice demo videos of it in use.

[efwd]

That thing looks like a piece of cake to replicate at home. Certainly John or Merril can do it.

[jrevens]

Thanks for that, Mike. I think that it would be even more ideal to draw the proper vacuum at the distribution tank at the top of the engine, then draw the antifreeze into the system at the drain plug on the radiator. That would seem to be the ideal technique. Some plastic tubing, a couple of valves, and a "jet-pump" or aspirator type vacuum source using air pressure from your compressor would be very easy to build.

[Xengineguy]

I’ve been filling systems this way for years. When you draw a vacuum on the
System there is very little air left in the system. The rubber hoses even collapse.
Refilling from the top works fine.
For best results drain the system before you pull vacuum,trying to top off a system has mixed results.

[oldfox]

ok guys looks like I have the wrong sensors or the wrong EIS for this motor talk to Rotax guy he said the motor would not even run if the EGTs where that high showed him the spark plugs and he told me they were burning great so stay tuned for more and thanks again guys for all the help.