 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
aoldman(at)xtra.co.nz
Guest
|
 Posted: Tue Jun 30, 2009 2:36 am Post subject: Rotax 503 running problem |
 |
|
Well said. 2 503s and no problems. First one I overhauled because there was
no reliable history with the engine, it was still performing well at 800 hrs
after the overhaul, no idea how many hours before the overhaul, the second
one only has 350 hours on it from new and going well. I have only ever run
castrol TT mineral oils at 50:1. It would seem that discussing oils is a bit
like discussing VGs ,there are a lot of opinions out there. The people
that make these things say 50:1 and I bet they have built at least a 50%
safety margin into that so I am happy to carry on with what I know works for
me, as for VGs ,while very interested in the change to performance VGs may
give I have been trying to think of when I would need them, or what
advantage they would give me and have to admit I can not think of one. The
Kolb MK111c behaves in a very predictable way and sometimes in marginal
conditions the quick stall onto the ground is not a bad thing and if the
conditions are not marginal it dos not matter . I guess if you needed to get
onto the ground real short and real slow then any advantage is a good
thing,I just have not found myself in the position yet that the MK111c was
not capable of handling . Like most things in life its all about compromise
, in order to gain something you may also loose something.
Keep it safe up there
MK111c
Downunder
original Message -----
From: "R. Hankins" <rphanks(at)grantspass.com>
To: <kolb-list(at)matronics.com>
Sent: Tuesday, June 30, 2009 8:00 PM
Subject: Re: Rotax 503 running problem
| Quote: |
Dale:
The 503 is the workhorse 2-stroke of the ultralight world. They are known
for their ease of operation, long life, and reliability.
I don't think you will find a whole lot of active pilots (especially those
who often fly over harsh terrain) who are willing to risk their health and
their airplane by running the 503 outside of long proven parameters.
I have never experienced so much as a hiccup from my 503. I decarboned it
at 119 hrs, changed oil brands and ran it to 450hrs. At that point I tore
it down and replaced every moving part because I happened to have the time
and money, not because the engine was showing signs of being tired. I
measured everything. The only component that was outside wear limits was
a small portion of the cylinder bore, just above the intake port. Even
that was less than 0.001" oversize. I probably could have gotten another
couple hundred hours out of it. The thing is, after spending several
years building an airplane, one doesn't really want to find where the
failure point of the engine is. I figured 150% of TBO was good enough.
There are many, many 503s out there that have flown past 1000hrs without
an overhaul, and literally thousands that have flown to twice TBO. Very
few actually get rebuilt at 300hrs. I guess what I'm getting at is what
do you stand to "gain" by adding more oil? It seems you are trying to
solve some perceived "problem" with the 503 that simply doesn't exist.
This is probably why Lucian questioned your experience. He wasn't saying
you don't know your way around engines in general, he was asking about the
503 in particular because anyone who has much time flying them knows they
are one of the most reliable two-strokes out there.
My first response when reading your post was "You're running 32:1? , Why?"
This is a great little engine that performs very well. All you have to do
is feed it right and keep the gauges in the green. Treat it kindly and
it will return the favor.
--------
Roger in Oregon
1992 KXP 503 - N1782C
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p 50718#250718
|
| | - 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 |
|
 |
dalewhelan
Joined: 11 Nov 2008
Posts: 105
Location: USA ARIZONA fountain hills
|
| Posted: Wed Jul 01, 2009 7:45 am Post subject: Re: Rotax 503 running problem |
|
|
I guess what I'm getting at is what do you stand to "gain" by adding more oil? It seems you are trying to solve some perceived "problem" with the 503 that simply doesn't exist.
My first response when reading your post was "You're running 32:1? , Why?"
I guess the best answer is that from my new to Rotax point of view, the engineers that claim 300 hour TBO also recommended 50:1
So I would have to say you are right, I was trying to solve a problem that does not really exist. From what I have heard, the motor goes quite beyond 300 hours on a very regular basis.
| | - 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 |
|
_________________
Dale Whelan
503 powered Firestar II, Luscombe 8A
Projection, A simple and interesting Psychological concept |
|
| Back to top |
|
|
dalewhelan
Joined: 11 Nov 2008
Posts: 105
Location: USA ARIZONA fountain hills
|
| Posted: Mon Sep 07, 2009 5:35 pm Post subject: Re: Rotax 503 running problem |
|
|
Finally getting close.
I got some advice the other day from somebody that has been doing this 28 years longer than I have, some of what he said made sense, some not as much.
Although the motor had been working fine, It was suggested that the prop was pitched too high.
I thought he was wrong but had to concede that he had over 28 times my experience.
The part that I did not buy is that the motor goes way rich at 5,800 RPM and won't run. I often cruise at this RPM and burn 2.5 GPH.
I got to thinking how my race bike makes more power cold than hot.
I also thought about the balancing act between prop load and Horsepower.
Then I thought what if the horsepower falls faster than prop load?
My friend does not feel like takeing off the 68" 3 blade prop on his 503.
The motor worked when he got the plane in the winter.
In the summer we can't get it to rev with the same pitch.
Last night he removed the single Mikuni and installed dual Bings.
The motor idled smoothly, ran for crap in the middle, and held 6,200 RPM on the ground up to 375 CHT.
I brought some Main jets and a smaller needle jet.
Middle is better, motor ran consistantly.
Seems the ballance was tipped by more power. I think it still has way to much prop. Next time we fly together, Greg plans to try my 66" 2 blade IVO.
We plan on putting my needles in his plane to see if that cleans up the mixture at about 4,200-5,500. We have the same needles but I want to make sure that lower time working needles don't work before trying different needles.
| | - 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 |
|
_________________
Dale Whelan
503 powered Firestar II, Luscombe 8A
Projection, A simple and interesting Psychological concept |
|
| Back to top |
|
|
aslsa.rng(at)gmail.com
Guest
|
| Posted: Mon Sep 07, 2009 6:05 pm Post subject: Rotax 503 running problem |
|
|
Dale, Download the various Rotax two stroke manuals at ROAN. When it comes to props Rotax has one consistent message. The prop must load the engine properly. Your friends 6200 static is just about perfect. If he goes over 6500 at full throttle in level flight it is too little pitch, not too much. Get the Bing manual and look up the correct jets for the model and setup of the 503 you have. Adjust mains only for altitude and temperature if necessary. Then check prop for proper loading.
When I was a kid there was an adage among owners of Brit sport cars (I had a Sunbeam Alpine). "95% of all carburetor problems are solved in the electrical system". With the Rotax, it's the prop.
Rick Girard
do not archive
On Mon, Sep 7, 2009 at 8:35 PM, dalewhelan <dalewhelan(at)earthlink.net (dalewhelan(at)earthlink.net)> wrote:
[quote]--> Kolb-List message posted by: "dalewhelan" <dalewhelan(at)earthlink.net (dalewhelan(at)earthlink.net)>
Finally getting close.
I got some advice the other day from somebody that has been doing this 28 years longer than I have, some of what he said made sense, some not as much.
Although the motor had been working fine, It was suggested that the prop was pitched too high.
I thought he was wrong but had to concede that he had over 28 times my experience.
The part that I did not buy is that the motor goes way rich at 5,800 RPM and won't run. I often cruise at this RPM and burn 2.5 GPH.
I got to thinking how my race bike makes more power cold than hot.
I also thought about the balancing act between prop load and Horsepower.
Then I thought what if the horsepower falls faster than prop load?
My friend does not feel like takeing off the 68" 3 blade prop on his 503.
The motor worked when he got the plane in the winter.
In the summer we can't get it to rev with the same pitch.
Last night he removed the single Mikuni and installed dual Bings.
The motor idled smoothly, ran for crap in the middle, and held 6,200 RPM on the ground up to 375 CHT.
I brought some Main jets and a smaller needle jet.
Middle is better, motor ran consistantly.
Seems the ballance was tipped by more power. I think it still has way to much prop. Next time we fly together, Greg plans to try my 66" 2 blade IVO.
We plan on putting my needles in his plane to see if that cleans up the mixture at about 4,200-5,500. We have the same needles but I want to make sure that lower time working needles don't work before trying different needles.
--------
Dale Whelan
503 powered Firestar II
Projection, A simple and interesting Psychological concept
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=261967#261967
===========
arget="_blank">http://www.matronics.com/Navigator?Kolb-List
===========
http://forums.matronics.com
===========
le, List Admin.
="_blank">http://www.matronics.com/contribution
===========
[b]
| | - 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 |
|
|
dalewhelan
Joined: 11 Nov 2008
Posts: 105
Location: USA ARIZONA fountain hills
|
| Posted: Mon Sep 07, 2009 8:12 pm Post subject: Re: Rotax 503 running problem |
|
|
I would have thought it perfect but that is all I pull on climb as well.
It is pitched Too high ( Just my opinion because I want max power for climb unless I decide to run lower RPM for cruise) and has excessive prop inertia.
A 503 on a B box does not need a 68" 3 blade Powerfin prop.
Kolb actually recommends a 60-62" IVO 3 Blade.
I am quite comfortable jetting 2 strokes.
All confusion was removed at the airfield today.
The motor runs rich on the second half of the needle
All that is left is basic carb jetting.
| | - 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 |
|
_________________
Dale Whelan
503 powered Firestar II, Luscombe 8A
Projection, A simple and interesting Psychological concept |
|
| 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
