---------------------------------------------------------- JabiruEngine-List Digest Archive --- Total Messages Posted Thu 02/06/14: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:19 PM - Rough running Jab 3300 (Gary Eady) 2. 11:36 PM - Re: Rough running Jab 3300 (Paul Mulwitz) ________________________________ Message 1 _____________________________________ Time: 11:19:40 PM PST US From: Gary Eady Subject: JabiruEngine-List: Rough running Jab 3300 I'm having a few issues with my Jab 3300 solid lifter engine. Intermittentl y, normally under load in the climb, it develops a miss in either one or ot her of the front cylinders. The miss/rough running only lasts between about 10 and 20 seconds and recurs every couple of hours or so of flying - but i s enough to make me look around quickly for an off field landing area.=0AHa ve checked the resistance and condition of the HT leads and also the coils. All seem to be ok.=0AThe errant cylinder is easy to track via the EGT prob es and is always number 1 or 2 which is suddenly about 100 degrees C cooler than the others.=0AThe engine has 70 hours on it and starts well hot or co ld - is burning no oil and throws virtually no oil into the breather bottle .. All engine parameters are great including cylinder head temps. Except for this darn miss.=0A=0AAnyone else out there having or had a similar problem ??=0A=0A=0ARegards=0A=0AGary=0A=0ACH701,- Jab 3300A serial number 500, 70 hours total time. Grand Rapids EIS. ________________________________ Message 2 _____________________________________ Time: 11:36:41 PM PST US From: Paul Mulwitz Subject: Re: JabiruEngine-List: Rough running Jab 3300 Hi Gary, First let me say I am no expert on engines of any sort. So don't depend on my being right. I once had some strange miss-firing because the carburetor was loose. It was more dramatic than your story and only went bad when I reduced to idle power for descent. The thing that comes to mind listening to your story is you are at a high angle of attack. That suggests there is something about the air flow to the carburetor might be funny. In my plane I took extra measures to straighten out the air flow just in front of the carburetor. There are several ways to do this, and I don't really know if any are necessary. A 3300 is a large engine for a 701. You must get very high pitch on the aircraft nose when climbing. This suggests a possible problem with fuel pressure could be involved. Do you have a boost pump? Good luck, Paul Camas, WA Zodiac XL, Jab 3300 On 2/6/2014 11:16 PM, Gary Eady wrote: > I'm having a few issues with my Jab 3300 solid lifter engine. > Intermittently, normally under load in the climb, it develops a miss > in either one or other of the front cylinders. The miss/rough running > only lasts between about 10 and 20 seconds and recurs every couple of > hours or so of flying - but is enough to make me look around quickly > for an off field landing area. > Have checked the resistance and condition of the HT leads and also the > coils. All seem to be ok. > The errant cylinder is easy to track via the EGT probes and is always > number 1 or 2 which is suddenly about 100 degrees C cooler than the > others. > The engine has 70 hours on it and starts well hot or cold - is burning > no oil and throws virtually no oil into the breather bottle. All > engine parameters are great including cylinder head temps. Except for > this darn miss. > > Anyone else out there having or had a similar problem?? > > > Regards > > Gary > > CH701, Jab 3300A serial number 500, 70 hours total time. Grand Rapids EIS. > > * > > > * ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message jabiruengine-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/JabiruEngine-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/jabiruengine-list Browse Digests http://www.matronics.com/digest/jabiruengine-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.