rehn(at)rockisland.com
Guest
|
 Posted: Sun Jun 02, 2013 9:05 am Post subject: Fwd: Carburettor Float Settings |
 |
|
[quote]Carl
I have just spent the last three weeks fighting carb issues and also installed the overhaul kit. I also installed new carb bowls as mine were deformed from over torque on the attachment bolt. I have also replaced the attachment bolt for the car bowl with the new type and oring. The new bolt has a recess for the oring and therefore holds the oring in place! I was unsure about the distance for the float arms as well. I reinstalled the old ones and measured the distance from the center of the arm to the flat area of where the main jet assembly is screwed in. So the carb is sitting upside down for this measurement just like the manual shows if you had the special rotax measuring device. Anyway I did see that they are parallel to the body, your can see this pretty well. I also measured from the center of the arm up to the carb flange that is right next to the arm and is a reference point to see if the arm is parallel. That distance was 11mm. I put the new arms back on and tweaked them so that they also are the same as old or 11mm. That puts them parallel also. This worked for me. My engine was running very rough at about 3000 rpm and then would bog down before the carb overhaul. After the overhaul I could move thru the rough area and smooth out again.
I went thru the mechanical balance and pneumatic balance,this helped but still had rough spot. From my rotax class they had a trouble shooting method for carbs. Set the rpm at 2000 after engine is warm, then slowly pull the carb choke out. The rpm should rise about 400 to 600 rpm then bog. That would be normal for main jet setting. Mine only gained 200 rpm which indicates to lean a setting. I moved main jet needles on each carb to a richer position, lowered the clip on each carb which raise the jet to a richer setting. Ran the engine and was much better and the rough spot went away. Long story but my engine is now running smooth again thru all ranges.
But I still have a separate issue with my yellow caution lite blinking. The rotax folks want me to send it (tcu) in for a diagnosis, looks like I will be doing that Monday. The light starts to blink at about 2300rpm and will stop if throttle down and then start again as rpms rose to about 2300. Even with the engine not running the lite will come on when the throttle is advanced and extinguish when pulled back. So looks like the throttle position sensor is working but maybe not correct or the tcu is not working. This issue was there before I overhauled the carbs so is not due to the overhaul.
I will start a new thread on this issue.
I will try attach a photo of the attachment bolt.
Good luck Carl.
Jerry
<image.jpeg>
Sent from my iPad
On Jun 2, 2013, at 1:57 AM, "Carl Pattinson" <carl(at)flyers.freeserve.co.uk (carl(at)flyers.freeserve.co.uk)> wrote:
[quote]Message <![endif]--> <![endif]-->
Hi,
Has anyone used the proper Rotax tool for setting the float levels.
We have just overhauled the carburettors using the Bing overhaul kit (nearly £300 from Skydrive) – this was long overdue and should be done every 5 years. I assumed that the supplied float operating arm would be factory set but it seems this is not the case.
According to the maintenance manual, a special tool should be used which I understand can be hired from Skydrive for a nominal charge. Looking at the manual it looks as though the float arms need to be parallel to the main carb body but I could be wrong in this assumption.
The upshot of the overhaul has been a rough running engine which upon investigation looks like a weak mixture. Conrad Beales website says that if you remove the float bowls after running the engine the fuel level should be 1’8 “ (3mm) from the top of the bowl – we had nearer 8- 10 mm. Looks like we need to order up the setting tool and do the job properly.
So back to the original question – anyone used the adjustment tool and how easy was this. Failing this is there another better way.
I spoke briefly to Kevin Dilks and he suggested that the float arms should be parallel(as above) but I’m not sure this is a precise enough setting.
PS: thanks all for your comments on THROTTLE STOPS – I am inclined to agree with Duncan in his observation that the carb stops are the main ones that can be overridden by applying gentle backpressure on the throttle lever to give a usefully reduced RPM on descent – with the cockpit stop acting as the safety backup to prevent damaging the carb throttle arms etc.
From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Duncan & Ami
Sent: 01 June 2013 08:53
To: europa-list(at)matronics.com (europa-list(at)matronics.com)
Subject: RE: Throttle Stops
Whilst complying with the LAA requirement for a throttle stop, it's useful to set up the cables so that the carb stops are reached first, followed closely by the stop on the throttle lever itself if the lever is deliberately pulled closed against the throttle lever stop. This limits any excess strain that can be applied to the cables, but provides a useful facility to temporarily pull down the idle speed in flight (which in any case will still always be well above the static setting, as the forward motion drives the prop). As soon as the deliberate backpressure on the lever is released, 'normal service' is resumed
This facility makes a usefully large addition to rate of descent and is helpful for landing in to short strips; it's like having an airbrake!
Duncan McF.
[quote]
--
| | - The Matronics Europa-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?Europa-List |
|
|
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
