Microlighters

Hi All

I thought I must ask you all to check your Rotax engine installation. I had a engine out in a Foxbat few month's back.

I was over the airfield doing a test flight when the engine started running ruff and died. Did a perfect landing. (Test flying is not for the fainthearted )

The carburetor vent pipe was rooted close to the exhaust system and the cable tie broke or melted I do not know. The pipe got to close to the exhaust and melted close. With the vent closed the carburetor started to vent trough the idle circuit and the main jet. The engine get's to mutch fuel and dies with fuel all over. I was lucky there was no fire.

THIS WAS NOT ONLY ON THIS FOXBAT. I have seen the wrong vent installation on some other Rotax installation.

The 912 must have a short vent pipe

I have attached a photo of this Foxbat installation, I did not take a photo after the incident but I have marked the problem aria.

Please Check your vent, a small thing like this can bring u dawn!!!!!!!!

Fly Safe
Goose

Thanx for that info Goose !!

We`ll have a look.

Thanks for the heads up Goose and urge all that have 912 installations to check this!

ps.
Your post however insinuates that this was the cause of the Foxbat accident on Friday which may be premature. I would however appreciate if anyone possibly has a photo of the engine of the new Aeroprakt A22 LS engine installation... anyone?

John Boucher wrote:Thanks for the heads up Goose and urge all that have 912 installations to check this!

ps.
Your post however insinuates that this was the cause of the Foxbat accident on Friday which may be premature. I would however appreciate if anyone possibly has a photo of the engine of the new Aeroprakt A22 LS engine installation... anyone?

Hi John

It was not my intention to insinuate that. The resent accident just reminded me of what happent to me. I have removed it.

Goose

No harm done Goose but once again thank you for being proactive and vigilance - sharing info such as this just enhances SAFETY and AIRMANSHIP

Just a general question to the experienced builders.

Is it not a good idea to wrap the exhaust pipes with an insulating material? I am busy building a VP1 with VW engine but was thinking of doing it if the exhausts end up under the cowl, in order to try and reduce heat within cowl. It will also prevent things like this.

Eddie

The builders like Boet & JeanTree can advise here I am sure.

I for one don't like hiding things which would inevitably obscure early detection of cracks on metal parts for instance.... just my thoughts!

Yes, what says the builders...?

joker wrote:Just a general question to the experienced builders.

Is it not a good idea to wrap the exhaust pipes with an insulating material? I am busy building a VP1 with VW engine but was thinking of doing it if the exhausts end up under the cowl, in order to try and reduce heat within cowl. It will also prevent things like this.

Eddie

Hi Eddie

A friend of mine wrapped his KR2's exhaust with that material and ended up with a lot of smoke in the cabin after take off Like John says ' Don't hide stuff', exhaust tend to rust underneath that stuff. I would rather ceramic coat the exhaust to keep the heat out

Goose

Tx Goose

John Boucher wrote: I would however appreciate if anyone possibly has a photo of the engine of the new Aeroprakt A22 LS engine installation... anyone?

Hi John

This is a A22 LS engine installation that I have posted. The aircraft had +/- 55hr on when the owner had a oooooops on landing. The photo was taken before engine removal to replace the engine mount.

Goose

Question: (Note** I may be referring to some other? carb vent line or even carb overflow cup drain)

Apparently the official rotax cold air induction box has connectors for these carb vent pipes. In other words Rotax wants the pressure in these to be carb intake pressure for correct mixture regardless if the box is drawing warm air thru an air filter or cold air with no filter.

In most installations not using the induction box, these tubes are simply venting into the engine compartment pressure.

There was some conjecture that in some installations that pressure would not match the intake pressure of the carb. Some even went as far as piping these to football inflation needles piercing the rubber of the air filters. And claiming that doing so improved power & leaned the previously over rich mixture.

Any one here with experience of this ?

Sorry for seeing this thread only now.
1 I NEVER wrap the exhaust pipes. ( I had to do a VERY tricky engine-out landing on a test flight with a NEW aerie. Not nice to be flying with a smoke filled cocpit. Briekmerke, manne!)

2 Those 2 plastic overflow pipes gets routed as FAR away from the exhaust system as is possible. These pipes and their well beiing is a pre-flight item BEFORE EVERY FLIGHT.

3 If your 912 installation does not have a feed-back restrictor on it`s petrol system, consider it un-airworthy until fixed.

Thanks Goose, for bringing this problem under our attention. We will "keep`em peeled!!"

A Bells for that Goose!!

Fly safe, and remember: NEVER TURN BACK WHEN U HAV EFAT !!

Boet wrote:Sorry for seeing this thread only now.

2 Those 2 plastic overflow pipes gets routed as FAR away from the exhaust system as is possible. These pipes and their well beiing is a pre-flight item BEFORE EVERY FLIGHT.

3 If your 912 installation does not have a feed-back restrictor on it`s petrol system, consider it un-airworthy until fixed.

Thanks Goose, for bringing this problem under our attention. We will "keep`em peeled!!"

A Bells for that Goose!!

Fly safe, and remember: NEVER TURN BACK WHEN U HAV EFAT !!

I have checked on other foxbats and the vent installation is the same on all
I will never fly a plane with this type of vent installation again

I have checked the foxbat does not have a return to tank

Goose

Boet wrote:Sorry for seeing this thread only now.
1 I NEVER wrap the exhaust pipes. ( I had to do a VERY tricky engine-out landing on a test flight with a NEW aerie. Not nice to be flying with a smoke filled cocpit. Briekmerke, manne!)

2 Those 2 plastic overflow pipes gets routed as FAR away from the exhaust system as is possible. These pipes and their well beiing is a pre-flight item BEFORE EVERY FLIGHT.

3 If your 912 installation does not have a feed-back restrictor on it`s petrol system, consider it un-airworthy until fixed.

Thanks Goose, for bringing this problem under our attention. We will "keep`em peeled!!"

A Bells for that Goose!!

Fly safe, and remember: NEVER TURN BACK WHEN U HAV EFAT !!

Buti, I routed those 2 little vent pipes away as far as possible, right to the bottom of the cowl. The very first flight after this brainwave I had an engine failure at 400 feet just as I increased speed. I landed, cut the pipes and since then no problem.

BE WARNED: You must be carefull not extend the pipes to be in the low pressure area at the bottom of the cowl.

Dankie Oom Priester. ....het ook so agter gekom ja! Pypies is stewig aan die enjin munt vas, an sal nie sommer by n warm kezos pyp uitkom nie, en as dit peteril lek, sal dit op die rediemejuiter lek, en da sommer die enjin afkoel ook!!