2 Attachment(s)
Re: older 912 ul heating up
Ok guys here is the update have about 20 hours on the old bird have 168 main jets in carb EGTs at 1550 F at max, coolant temp at 230 F max , cylinder head temp 260 F runs great. Still not sure why I had to open up jets to get to right temps?? Here are some pic of the plugs, one from each side what do you guys think of color of plugs . Still looking for cause
Re: older 912 ul heating up
Color looks about right to me; if anything maybe a tad on the hot (lean) side.
Re: older 912 ul heating up
I don't see any sign of the white thermal paste you should be using. Definitely use it, it will cool the plugs somewhat.
Re: older 912 ul heating up
I think the color is darn near perfect. The gaps seem to be a little different but that may just be the different photo angles. I do agree that the larger jetting is compensating for a different carb problem. Such as incorrect fuel float level and/or sinking floats.
Re: older 912 ul heating up
The carbs are brand new ?? But I will check height of floats and adjust to the heavy side and see if I can get to run rich. thanks for the help guys love flying this plane.
Re: older 912 ul heating up
Just because they are new doesn't mean they don't have bad or badly adjusted floats in them. There have been several series of bad floats coming out of Rotax (Bing) in recent years.
I agree with Danzer1, those jets are unnecessarily huge and masking a different problem. What about the rubber boots between the manifolds and carbs? What about the o-rings on the intake manifold to head seam?
Re: older 912 ul heating up
It has been suggested before, but have you checked your vent lines.
These make a huge difference.if they are vented into the K&N type filters like mine you will need to be up a jet size or two.
Re: older 912 ul heating up
Mine are vented into the K&N filters and needed no jet change from the standard.
Re: older 912 ul heating up
Re: older 912 ul heating up
I need to check the float height but seems to me if floats were low you would run out of gas at WOT on take off I have replaced all the rubber O rings and carb flange boots and ran motor spray down intake manifolds looking for leaks it is good but I’m not giving up . Guys have a great 4th holiday