 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
John Hauck
Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)
|
 Posted: Wed Jan 23, 2008 5:55 pm Post subject: Mag Drop 912ULS |
 |
|
Hi Gang:
Well, I'm still sorting through causes for my mag drop, 200 one side and 400
the other side at 4,000 rpm. I oiled the throttle cable clevis connections
at the carb throttle levers. That didn't solve the problem.
Travis had sent me a set of plugs. Installed those and still got a drop of
200 and 400. The old plugs had 70 hours on them.
Now I am a little stumped. So....while I was sitting at the end of the run
way doing these mag checks, I reached up and pulled the enricher on full.
Momentary rpm drop, then the tach went to 4,200 rpm. Now...I did the mag
check with enricher off: 200 and 400 rpm drop. Pulled the enricher on,
performed the mag check and got 150 rpm drop on both sides.  Easy fix.
Raise the fuel needle a notch. Will have to do that tomorrow. Was getting
too dark and too cold to mess with it this evening.
Back in 1994, on my first flight to Alaska, I encountered some terrible
engine problems as soon as the temps dropped down into the 40's. The engine
was new to me, having flown it less than 100 hours prior to departure for
Alaska. Those hours were all flown in moderate to hot temps. No problems.
It really got bad between Cold Foot and Dead Horse, Alaska. I landed on the
road 60 miles south of Dead Horse. Changed plugs, fuel filter, dumped the
float bowls, and whispered a very sincere prayer. Made it into Dead Horse
and the remainder of my flight home. However, I had no idea what was wrong.
It did get better when I opened up the idle screws while weathered in for
four days at Dead Horse. I wasn't willing to tear into the carbs on this
new engine where I was located for fear of losing a part and not being able
to replace it.
When I got home to Alabama and Winter arrived, I discovered the enricher.
On a flight to Lucedale, MS, on a very cold day, the engine started losing
that nice crisp feel it normally had. I pulled the throttle back to 4,000
rpm and pulled on the enricher. RPM increased to 4,200 rpm. When I
got back to Gantt International Airport I tore into the carbs. Raised the
fuel needles a notch and never looked back, nor had a mid-range leaning
problem again. Guess that is what it is going to take to get the new 912ULS
tweaked up to where she belongs.
My last 912ULS was not sensitive to cold and mid-range blues. I flew it to
Alaska a couple months after I installed it. In fact, flew this engine to
Alaska twice. Never had a problem the 1,233.0 hours I flew it. Just goes
to show, they ain't all alike.
john h
mkIII
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama |
|
| Back to top |
|
 |
JetPilot
Joined: 10 Jan 2006
Posts: 1246
|
| Posted: Wed Jan 23, 2008 6:10 pm Post subject: Re: Mag Drop 912ULS |
|
|
Thanks for the engine info. I have never flown my 912-S in cold weather. I would have never thought a 4 stroke engine would have been that sensitive to temps. Now when I do fly cross country, and it happens, I will know how to fix it easily enough 
Mike
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
_________________
"NO FEAR" - If you have no fear you did not go as fast as you could have !!!
Kolb MK-III Xtra, 912-S |
|
| Back to top |
|
|
ElleryWeld(at)aol.com
Guest
|
| Posted: Wed Jan 23, 2008 6:33 pm Post subject: Mag Drop 912ULS |
|
|
Up here in the North country we usually have to adjust our needles in the Carb's two times a year when it warms up and when the temp drops I usually wait till the first sign of a needed adjustment then do it then and run without a hitch the rest of the season untill the weather temp changes and your engine will let you know when to make the next adjustment
Ellery in Maine Building one flying thing after another
Do Not Archive
Start the year off right. Easy ways to stay in shape in the new year.
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
lucien
Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM
|
| Posted: Wed Jan 23, 2008 7:11 pm Post subject: Re: Mag Drop 912ULS |
|
|
I've flown my 912s for about 100 hours now in cold and high-altitude weather with no problems running-wise, but there were a couple things I had to correct (apart from some damage in the 1/3 float bowl) going to the higher altitude of my airport (about 6300'):
- the idle mixture at the factory setting is too rich and gives a pretty fuel fouled plug after idling for a little while. I chased this a while on the 1/3 carb and just discovered the 2/4 side is also idling too rich at annual a few weeks ago. I had to go in a half turn on the idle mix screw on 1/3 and looks like I'll have to do thta on 2/4.
- the carburettor vent tubes have to be at the same pressure as the intake venturis on the carbs, meaning the vent tubes have to go into the air cleaners if you're not using the air box. Otherwise, the carbs run noticeably rich at high altitudes. I made some fittings for mine with brass barbs from Lowes and that completely cured the rich running.
As for ignition possibilities for the mag drop, one possibility could be the spark plug wires and/or the caps. The caps are a frequent maintenance item on the 2-strokes, the parts inside, the resistor assy ,etc., deteriorates and breaks, leading to sometimes strange behavior.
Havn't encountered any problems with the ones on my 912, but they don't look like nothin' special to me....
If the plugs are ok and the ignition stuff is ok, it could very well be the wires/caps messing up the works?
LS
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
_________________
LS
Titan II SS |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
