7DeltaLima
Well Known Member
I'm sure there is a simple solution but... how can I check to verify that a mag is in fact firing or not?
I flew Young Eagles for about 3 hours last Saturday so was a constant hot start exercise. No problem for all the flight but when I went to start the plane to put it back in the hangar I could not get the plane to start... It's an IO360A1b6 in a RV7A.
Best way to describe it is just hot start that I missed catching on the first attempt. Then thought I'd flooded it, etc. It would hit a lick or two then die. Finally gave up and got a tow to the hangar. Came back a couple days later assuming that the flooding stage was over so I assumed it'd start right up. Still no joy. Pulled plugs. Look good but cleaned/dryed them anyway.
Finally got to the point it wouldn't even hit. Put the buzz timing box on to check mag timing. Left impluse mag light would never stay solidly lit. Basically, showing constantly closed points. It would only blink quickly when pulling the prop through. Right mag showed okay.
Found the Slick mag overhaul manual ... pulled the left mag (first time for that... guess this is the educational part huh...) There seemed to be a spot, maybe the size of a pencil point between the points that was probably keeping the points from opening. Like an arc point.
I sanded the points...set the e-gap according to manual, installed the mag, set the timing..(buzz box showed all okay).... totally excited just knowing that I've solved the problem. No joy. still will not start.
Have fuel flowing. Mag shows timed correctly, 25* bdtc... even remembered to pull through to release the impluse coupler.....
I've ordered a new mag that'll be here tomorrow as I'm still thinking I'm not getting spark. I'll install tomorrow night but before doing so just wondering how would you check to see for sure if you are getting spark or not.
Remember the old days in the farm trucks of pulling the plug and laying it up on the manifold, taking a screwdriver and shorting the starter and watching the sparks jump across the plug to verify spark. Gotta be something that would accomplish the same thing but more eloquently by putting a light between the wire from the mag and the plug... maybe...
any ideas....
thanks.
Doug
I flew Young Eagles for about 3 hours last Saturday so was a constant hot start exercise. No problem for all the flight but when I went to start the plane to put it back in the hangar I could not get the plane to start... It's an IO360A1b6 in a RV7A.
Best way to describe it is just hot start that I missed catching on the first attempt. Then thought I'd flooded it, etc. It would hit a lick or two then die. Finally gave up and got a tow to the hangar. Came back a couple days later assuming that the flooding stage was over so I assumed it'd start right up. Still no joy. Pulled plugs. Look good but cleaned/dryed them anyway.
Finally got to the point it wouldn't even hit. Put the buzz timing box on to check mag timing. Left impluse mag light would never stay solidly lit. Basically, showing constantly closed points. It would only blink quickly when pulling the prop through. Right mag showed okay.
Found the Slick mag overhaul manual ... pulled the left mag (first time for that... guess this is the educational part huh...) There seemed to be a spot, maybe the size of a pencil point between the points that was probably keeping the points from opening. Like an arc point.
I sanded the points...set the e-gap according to manual, installed the mag, set the timing..(buzz box showed all okay).... totally excited just knowing that I've solved the problem. No joy. still will not start.
Have fuel flowing. Mag shows timed correctly, 25* bdtc... even remembered to pull through to release the impluse coupler.....
I've ordered a new mag that'll be here tomorrow as I'm still thinking I'm not getting spark. I'll install tomorrow night but before doing so just wondering how would you check to see for sure if you are getting spark or not.
Remember the old days in the farm trucks of pulling the plug and laying it up on the manifold, taking a screwdriver and shorting the starter and watching the sparks jump across the plug to verify spark. Gotta be something that would accomplish the same thing but more eloquently by putting a light between the wire from the mag and the plug... maybe...
any ideas....
thanks.
Doug