Air filter popped out in flight

[Walt]

Originally Posted by DFly

First post to this forum, we have an RV7A freshly out of its 40 hour fly off that experienced this same problem in the HOT weather in Texas. After refueling and restarting, we experienced a backfire during our hot start up. When we applied power on the takeoff roll after a normal runup, the engine did not develop appropriate power and we aborted the take off. Upon inspection, our airfilter - attached in a very similar way to those shown here - was actually displaced.

Again about 10 hours later (also in very hot weather), we experienced a small backfire after a hot start. So we shut down and inspected; the filter was deformed as in Merlin's post.

Now chasing the cause of these backfires (haven't experienced them in the cooler weather as we flew to Oshkosh from California) but know that any backfire with this horizontal induction filter will signal shutdown and inspection of the filter. One is on order to replace the current part - and they are not cheap!!!

What ignition system do you run? Does the engine crank properly?
A properly setup/operating engine should basically never have a backfire.

[rv8ch]

I had a similar incident, and this was the result. I replaced the filter with a new one.

[Mike Harris]

Crimp the holding metal down to lock the filter tighter.

[Smilin' Jack]

I could be wrong but the snorkel on the backside side if the filter is suppose to be under a metal flange which is part of the baffling. Looks like it is completely outside of the baffle near the cylinder. But I would not have an answer for the bend in the filter. Something definitely caused a back flow with an abundance of pressure to buckle it up

[Warp10]

Originally Posted by DFly

First post to this forum, we have an RV7A freshly out of its 40 hour fly off that experienced this same problem in the HOT weather in Texas. After refueling and restarting, we experienced a backfire during our hot start up. When we applied power on the takeoff roll after a normal runup, the engine did not develop appropriate power and we aborted the take off. Upon inspection, our airfilter - attached in a very similar way to those shown here - was actually displaced.

Again about 10 hours later (also in very hot weather), we experienced a small backfire after a hot start. So we shut down and inspected; the filter was deformed as in Draker's post.

Now chasing the cause of these backfires (haven't experienced them in the cooler weather as we flew to Oshkosh from California) but know that any backfire with this horizontal induction filter will signal shutdown and inspection of the filter. One is on order to replace the current part - and they are not cheap!!! Going to try that hot start with Throttle only open half like wnplt and see if that helps!

I also had this thru the intake snorkel backfire.. After talking to Air Power on my IO3601m, I was told the idle mixture was set to lean. Adjust the idle wheel to make the mixture richer during starts... No more backfires.

You may need to adjust the Idle RPM after making mixture richer.