Electroair Rough Running

[chaskuss]

Originally Posted by rocketbob

You have a bad pickup sensor. You can get a new one from Electroair or from the original manufacturer, which is Electromotive.

http://www.electromotive-inc.com/sensors.html

part # 250-72212

I carry a spare with me in my tool bag.

James,
As Bob mentions, there was a fair number of failures of the older 3/8" diameter pickup. You might want to consider upgrading to the newer 1/2" diameter pickup (255-72218). You will need to remove the adapter housing to enlarge the hole that the pick up mounts into, to 1/2" diameter. This will allow the use of the newer style pickup.
Charlie Kuss

[az_gila]

Originally Posted by chaskuss

James,
As Bob mentions, there was a fair number of failures of the older 3/8" diameter pickup. You might want to consider upgrading to the newer 1/2" diameter pickup (255-72218). You will need to remove the adapter housing to enlarge the hole that the pick up mounts into, to 1/2" diameter. This will allow the use of the newer style pickup.
Charlie Kuss

....or sell me your old magneto hole adapter housing so I can use it....

Somehow...in a loan to another builder to keep his plane flying and a shipment to Jeff Rose, the housing adapter got lost...

[rocketbob]

Originally Posted by chaskuss

James,
As Bob mentions, there was a fair number of failures of the older 3/8" diameter pickup. You might want to consider upgrading to the newer 1/2" diameter pickup (255-72218). You will need to remove the adapter housing to enlarge the hole that the pick up mounts into, to 1/2" diameter. This will allow the use of the newer style pickup.
Charlie Kuss

I have a friend that had nothing but trouble with the 1/2" pickup in the magneto housing. After trying 2 of the 1/2" variable reluctance pickups, he machined an adapter and went back to the 3/8" pickup, no problems since.

[PocketRocket]

To update you all:

I found that I was low on compression on #1 cylinder and removed it to find that the inlet valve is not seated properly. This seems to have allowed the ignited mixture to penetrate back down the inlet tube, and when the cylinder is under maximum pressure, I think this is going all the way back to the mixture plenum. If it doesn then this could then burn the charge going to the other cylinders - hence the irregluar rough running. When I was switching off the second mag, this must have been lowering the cylinder pressure enough to prevent the mixture burning in the plenum. Does this sound plausible

Thanks for all your replies.

James
G-JSRV

[jclark]

Originally Posted by PocketRocket

To update you all:

I found that I was low on compression on #1 cylinder and removed it to find that the inlet valve is not seated properly. This seems to have allowed the ignited mixture to penetrate back down the inlet tube, and when the cylinder is under maximum pressure, I think this is going all the way back to the mixture plenum. If it doesn then this could then burn the charge going to the other cylinders - hence the irregluar rough running. When I was switching off the second mag, this must have been lowering the cylinder pressure enough to prevent the mixture burning in the plenum. Does this sound plausible

Thanks for all your replies.

James
G-JSRV

Don't know if this is your problem though it seems to have merit.

After over 1000 hours, our Jeff Rose/ElectroAir system has been running fine. During initial tests, I had some problems and it turned out to be wiring harness issues. Make sure you have good caps on the end. I would get what seemed like a backfire under high load (max power climb tests).

But, since you have had a scope on the system this has probably been ruled out.