Europa-List Digest Archive

Fri 05/17/13


Total Messages Posted: 1



Today's Message Index:
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     1. 08:09 PM - Re: 914 rough running (Jerry Rehn)
 
 
 


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    Time: 08:09:00 PM PST US
    Subject: Re: 914 rough running
    From: Jerry Rehn <rehn@rockisland.com>
    Bud I have the new float chambers and new orings for the retraining nut and now s ee the oring wants to buldge out a bit on torquing down. I assume the new re vised bolt has provisions for the oring that the current bolt does not. You i ndicated that yours worked ok. I am hoping to not have to purchase the new b olts at about $80 each! But I am not happy with the oring not fitting perfectly. I see you left the o ld washers in place as well, I don't see how that will keep the oring from p ressing out. I torqued down to only 46 inch. I didn't lube them, thought thi s would make it worse? Tomorrow I will try some lube but welcome any other s uggestions. Thanks Regards Jerry Sent from my iPad On May 6, 2013, at 2:41 PM, "Bud Yerly" <budyerly@msn.com> wrote: > Jerry, > Please note that the 914 is a bugger to troubleshoot, and all the advice s o far is notable and spot on. > > Since the engine has two problems: (1) Rough after pulling it back and (2) TCU Caution light, I will deal with 2 first... > > 2. The caution light is most probably your throttle pot is not hooked up e lectrically or the pot was not set to idle with the throttle plate closed so check your connections and pot rotation after doing the carb. Easy mistake , especially since the book doesn't cover it. If not set properly, the TCU g ets the wrong throttle position for the Turbo boost and pressure sensors. > > 1. With you having the same hours I have on my engine, I have noticed tha t with all the tubing and carb float bowl items operating properly and no fu el leaks, the engine on power reduction runs very rough but idles well and r uns well above 4000 RPM. I suspect yours is similar. > > It is not uncommon that one of the carb pistons is hanging up. Once the p iston goes up on full throttle, one doesn't want to come down. I removed th e carburetors again. I completely drained and freed both my carbs of fuel t o prevent an explosion. I rigged my vacuum cleaner and pulled air from the m anifold side and noted the movement of the piston. On the left carb it was c learly hanging up. After much cleaning, sanding with 1000 and 1500 grit pap er, polishing and more cleaning, the piston is acceptable in its movement an d smoothness. If your carb pistons move smoothly and in unison (checked by n oting the throttle angle vs piston position) then that should make the carbs balance in the mid range. If the main carb body is worn or scored badly, s ome small grit has gotten into the carb and I am afraid you can save a lot o f time and trouble by buying two new carbs. By the way, that is about the p rice of a small car down payment. > > To Bob Borgers comment, I have found that leaving the float bowl gasket in place and adding the new extra O ring (with a bit of lube) allows me to ins tall the original float bowl attachment screw and I torque it to 48 inch pou nds. Be sure to soak your paper gasket in fuel for a few minutes. Note tha t the old manual said 5.5 nm or 45 foot pounds. Obviously 45 foot pounds is going to seriously bend the bottom of the carb bowl and the pins. Luckily, a quick $100 per float bowl will fix that. I have found that it necessary t o pay attention to the translation and conversions in the old manual. The n ew manual has the torque hidden in the verbage so well that I had to post it to my board in the shop. Please pay close attention to your brass float pi ns and the float bowl. Also make sure your float needle valve and arms are u ndamaged. > > I have been very disappointed in the fit of the new carb parts such as the needle fixation screw with the O ring. It sucks. > > I hope your carbs just need a little tender love and care and not replacem ent. I am at my last straw with my 1/3 side carb, so I may be spending some big bucks. > > Regards, > Bud Yerly > > > ----- Original Message ----- > From: Jerry Rehn > To: europa-list@matronics.com > Sent: Sunday, May 05, 2013 3:43 PM > Subject: Europa-List: 914 rough running > > A little history. Engine has about 450 hours, always ran quite well, repla ced upper ignition module about two years ago. > On recent full boost takeoff, got to about 900 feet leveled off, pulled th rottle back and engine ran severe rough, pulled back to idle and engine ran o k, didn't stop! Landed. Checked fuel filter, ok, looked for anything around c arbs, nothing. Tried several full run ups, ok. Tried second take off everyth ing fine, pulled back and again engine ran severe rough, pulled back to idle , ran rough, landed. Parked plane, got tools, next day removed carbs looked f or issues. Found one of the four screws that holds down the rubber diaphragm loose, very strange because I have never removed this before. Anyway figure d this was my problem. Fixed took off all ok. Got home. Next day tried full b oost, same issue again, didn't take off. Got carburetor repair kit and went t hrough both carbs. Reinstalled carbs double checked. Started right up, as I m ove the throttle past 2300 rpm the yellow caution light starts blinking, eng ine runs rough, reduce rpm the light goes off, increase the light comes back on. Seems the engine runs off the idle jet ok but not on the main jet. > I have also checked the waste gate for proper function, fuel pressure ok, t urbo lights come on and go off as they should when master is tuned on, I hav e looked at the vent lines. The yellow blinking light can indicate a sensor f ailure, seems like it would continue blinking if there was a failure. Seems o dd that it stops at low rpm. Seems I have some kind of a vacuum or pressure i ssue, but am running out of ideas. I am about to go and recheck again! Could a faulty sensor cause this? > Hope someone out there has some wise thoughts on this frustrating problem. Worse yet, we have beautiful spring flying weather! > Thanks for help. > Jerry > 914 Mono XS > > > href="http://www.matronics.com/Navigator?Europa-List">http://www.matronh ref="http://forums.matronics.com">http://forums.matronics.com > href="http://www.matronics.com/contribution">http://www.matronics.com/c > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= >




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