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GDN
09-18-2009, 01:10 PM
I just bought a Kitfox model 2 with a 582 and my instructor thinks that the engine produce a lot of vibrations in the cabin;

Is there anybody noticed such problems ?

Excuse me for my bad english i'm french.

SkyPirate
09-18-2009, 07:26 PM
hello GDN,..if you have vibration you need to syncronize your carbs ,..check the carberator jets to see if they are the same size and check to see if the needle is set on the same gernal


bonjour GDN.. si vous avez la vibration vous avez besoin Ã* syncronize de votre carbs.. vérifient les jets de carberator pour voir s'ils sont la même grandeur et le chèque pour voir si l'aiguille est mise sur même gernal

Chase

GDN
09-19-2009, 01:37 AM
OK i'll see synchro, for the needle they are at the same position (3) for the jet i'll see. Thanks

SkyPirate
09-19-2009, 06:03 AM
providing that all is set the same internally on the carbs ,..now make sure that they are both opening and closing together in time ,..

if it's not the carbs then check your prop,..if it's a wood prop and the finish is worn,..you might have more moisture in one of the blades then the other making it unbalanced,..if its a composite ground adjustable prop,..the blades might not be all set at the same degree ,..look for knicks and or cracks in the prop.

if is not the carbs or the prop ,..then check the lash on the gear box,..how many hours on the engine and gear box?,..check lube level in gear box,..check to see if the shaft to prop moves up or down,..in or out.
try to twist the shaft by pushing in on a top blade and pulling out on a bottom blade,..and back and forth

if it's not any of the above items ,..then check motor mounts,..if one is broken and someone put a solid mount on one of the mounts,..clearances on the motor to the motor mount,.. motor mount connections to fuselage

in low idle ,..the 582's will vibrate and also on shut down,..but usually once you get above 2,000 rpm the vibration dampens.

if all is good after checking ,..then it's back to the carbs ,..time for a rebuild,..during rebuild ,..check needle for straighteness,.make sure all gernals in carb are clean,.

when you pull the bowls to check the jet sizes ,..any debri in the bowl?
fuel filters ,..is there one for each carb or one for both?

Chase

GDN
09-20-2009, 12:05 PM
All is ok !

The big problem of this Kitfox is no flight during six months so after complete unmount of the 2 carbs and complete good cleaning now is turning like a swiss clock !

Thanks for all your aid i am proud to become a member of the kitfox family.

Oliver

SkyPirate
09-20-2009, 01:52 PM
great :D and welcome aboard

Chase

GDN
09-27-2009, 12:49 PM
Bad news.

Finally after trying the aircraft on runway with any take off my instructor feel very bad at return. He says " i have the feeling that the engine will come on my knees !"
I tested it myself and until 3000 rpm lots of vibrations after it clean and smooth.

Is anybody knows the value in shore of the silentbloc mount for the 582 Rotax on a KF2 ?

Carb syncro + propeller changed + so ?:confused:

GDN
09-27-2009, 12:51 PM
Excuse me but i've got bad technical english what the meaning of "LASH"
The engine has, if i believe it's previous owner, 100 hours, i check the gearbox oil level it's OK.

SkyPirate
09-29-2009, 08:14 AM
"lash" is a term meaning spacing between gear teeth,...usually it ranges between 4000ths and 6000ths,..if your still getting vibration I would go to the prop to check it's balancing,..cracks,.knicks ,..excessive wear ,..check all blades if it's a ground adjustable to insure they are all set at right degree ,..measure from hub to tip on each blade,..to ensure all blades are the same in length,..I say this because I have had an incident where a previous owner sanded almost 1/8" off of a tip on one blade to hide a scar,..it took me a while to figure out where the vibration was coming from ,..not until after I had replaced the prop and stood the old blades up in a box for storage , then I see the shorter blade.


Chase

Av8r3400
09-29-2009, 09:13 AM
Or: .004-.006" (.10-.15mm) clearance, usually checked with wires or feeler gauge material.

Robin G
09-29-2009, 11:23 AM
I have experienced similar conditions with both 582 gray and blue heads on my model 3. Very rough idle below 3,000 rpm, then everything smoothes out. (When I purchased the airplane from the original builder, the altimeter needed to be replaced because it had shaken itself to death from too low an idle setting). Carbs are sync'd and jetting is correct for smooth operation and correct temps in flight. ROTAX mechanic on my field played with the idle adjustments on the carbs and things are smoother, but still kind of rough under 2,800. Personally, I have never known either of my 582s to idle particularly well at lower RPMs. I have only used B boxes with each engine. Depending on the time on the engine, you might want to have somebody look at the gears and shims as excessive vibration over time will definitely loosten thngs up. I would encourage you that you can smooth it out, but it is a process not an event.

GDN
09-29-2009, 11:24 AM
For the propeller i tried an other one and same problem i would like to put new engine mount because they are 18 age old...
For the lash i shaked the propeller mount in all directions no suspect movments...

I asked John Mc BEAN to have the mount model but no response
they seem like standard rotax models but i don't know about the straightness there is light medium and strong ones...

Is anyone knows how model are they i will be glad :)

GDN
09-29-2009, 02:08 PM
I have John Mac Bean by phone but he asked me a part number.

I haven't any in the buiding documentation only called E-10
For the bolt and nut i have like ANXX-XXX.

Is any KF2 builder can check his documentation to confirm ?

Thanks

GDN
10-17-2009, 01:50 PM
i received my lord engine mount today from KF aircraft.

I cross my finger and hope that will stop my vibrations problems :(

Put them tomorrow...

GDN
11-10-2009, 06:20 AM
I put my engine mounts ...same
I changed the gearbox B for a C model ...same

And one day a guy coming from nowhere said "hey did you see...your muffler is touching your aircraft structure.

I fix it differently with the springs and now all it's ok :)

So now i've got a B model gearbox to sell if anyone interested PM.

So i'll finally going to fly with that KF...