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PostPosted: Sun Jun 04, 2006 3:17 pm
by daffy1029
Hi Everyone,
I am just curious, does anyone use EGT (exhaust temp. guages) on your Lazairs?
I used to, back in 1985, on my Rotax 185's, and found them very useful. It's great for tuning carbs to the max, without seizing the engine. Back then, I kept them below 1150 degrees F at full power. And if they went over a little, I could back the throttle down a little, and carry on, because the temp would fall at a lower throttle setting(but this indicates a lean setting). I think I will get another dual EGT gauge for my newer Solo engines.

PostPosted: Sun Jun 04, 2006 5:47 pm
by Guest
No need for EGT's on direct drive tractor engines tuned properly ???

PostPosted: Sun Jun 04, 2006 11:07 pm
by daffy1029
Hi guest,
How do you know if your engines are tuned properly for sure?

PostPosted: Mon Jun 05, 2006 6:45 am
by Guest
What is the correct exhaust gas temperature ?

PostPosted: Mon Jun 05, 2006 8:54 am
by Guest
The Mark 3's run all day long at full power ON THE GROUND ! EGT ? Why bother ?

PostPosted: Mon Jun 05, 2006 11:02 am
by flyalaz
I have a card from the Rotax mechanic near here that shows CHT and EGT for both air and liquid cooled engines. Here is the 2 stroke air cooled scale. Note: the card specifies these engines. 277ul, 377ul, 447ul, and 503ul. Not sure if it applies to the 185's.

The EGT green range is from 860 to 1080 degrees F, and starts in the red at 1200 F. The CHT is green from 350 to 430 degrees F, and goes into the red at 480 F.



PostPosted: Mon Jun 05, 2006 11:19 am
by russell
From my motorcyle days, aluminum melts at 1220 deg. F (660 C). Just thought I'd throw that in.


PostPosted: Mon Jun 05, 2006 5:52 pm
by daffy1029
Hi guest,
If you run engines on the rich side no problem, but you won't go as far on a tank of gas unless you lean the carb as much as you can without doing any damage to the engines. Egt gauges would help a lot in peaking out your max gas mileage and power. Daffy

PostPosted: Tue Jun 06, 2006 1:50 pm
by Guest
Clearly not needed for the Rotax 185s.

PostPosted: Sat Jun 10, 2006 10:13 am
by daffy1029
Hi Guest,
Rotax are prone to siezures like any other 2-cycle engine, if leaned out too much. It doesn't matter what make of engine, EGT gauges shows you what's happening in the cylinder. If reading is low, that means too rich a mixture, and if too high, a chance for the piston to seize to the cylinder walls. It won't show you if the bearings are about to seize (that happened to me once). EGT will show you if a seal starts to go. If a seal starts to go, then your EGT gauge will rise, because now you have a lean mixture, just because of the extra air coming in. I think it would be a usefull gauge- more useful then a cylinder head gauge. Head temperature gauge reacts too slow, for a siezure about to happen, but are still somewhat useful as well.
It appears that many Lazair flyers like to get as much power out of their engines as they can and I think this is a safe way to do it. Daffy