912UL Issues

[Av8r3400]

I did the whole reassemble in reverse order thing today. I installed the new "spring discs" into the assembly replacing the partially collapsed old ones. There really wasn't anything to photograph with that, so...

I did take a couple of shots of the press tool used to disassemble the gear box shaft assembly.

1st photo: This tool is intended for the "B" Rotax 2-stroke box. This is the same tool they use at LEAF, on the 912/914 boxes too. They told me they modified it to fit the larger box. I didn't want to modify the tool (it isn't mine) so I made some shims to help it fit the larger gear better.

2nd photo: Here is what the tool looks like by itself on the gear.

3rd photo: Here is with the shims to spread out the force on the gear a little more.

You put the assembly in the press, supporting the prop flange and then press on this bridge until the retainer clips release. Easy peasy.

[Av8r3400]

My last hope didn't help. The vibration is just as bad as ever.

[68niou1]

My last hope didn't help. The vibration is just as bad as ever.

Stupid question- have you replaced your engine mount rubber isolators recently? Just a thought-

[Av8r3400]

No I have not. Something to consider I guess...

[68niou1]

Was yours really smooth before? Because at anything below 2500 mine isn't really smooth, and from what everyone is telling me that is normal on the 80UL. While I don't have very much time in mine yet- I did spend quite a bit in Paul Leadabrand's 914 model 7- and that is night and day compared to mine. His is smooth from any rpm, and I have been told a lot of that is the engine mount from the model 4 to the model 7-

[Av8r3400]

I bought the plane with 72 hours TT. It ran turbine smooth at all rpm until last year at about 400 hours TT.

It started as an intermittent "rough running" range in the rpm band. At the low power, approach rpm range, 2500-3000. Just a little rough and it would come and go. It has progressively gotten worse over the last ~40 hours of run time. Through out that time I have reset, then disassembled and cleaned then totally rebuilt the carbs. Each time balancing them with our chapter's electronic balancer. I even balanced the prop with a DynaVibe unit.

Doing the spring discs in the gearbox was the last item on the list. Now I start over with a new list...

Monday I'll be calling LEAF and Lockwood looking for more ideas.

I'll gladly accept any other ideas on this problem. Don't be shy.

[JimS]

Larry,
Probably a stupid question but have you changed plugs lately?

JimS

[Av8r3400]

Plugs have ~20 hours on them.

I had a suggestion of maybe looking at the plug wires, though...

[Av8r3400]

Does Kitfox still have/produce the engine mount rubber isolators, pn 44024.000? (Per S/B 54A)

I tried calling today, but they must have have been sleeping off the fly-in this past weekend...

[kmach]

Does Kitfox still have/produce the engine mount rubber isolators, pn 44024.000? (Per S/B 54A)

I tried calling today, but they must have have been sleeping off the fly-in this past weekend...

Hi , They do. I got part # 44024 and # 44023 from them in the spring.