• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

O-200 Ignition Issues

D

Dan Gervae

FRIEND
Upper Peninsula of Michigan
I’ve been taxi testing and running my O-200 in my Exp 11 and have a problem....it starts and runs good on both mags, but when I switch to just Left, or Just Right, it runs rough and pops and backfires. Any suggestions?
 
I did run it with P leads unhooked and grounded one then the other mag....runs rough. I’ll check internal timing and harness and plugs next
 
Dan Gervae said:
I’ve been taxi testing and running my O-200 in my Exp 11 and have a problem....it starts and runs good on both mags, but when I switch to just Left, or Just Right, it runs rough and pops and backfires. Any suggestions?
Click to expand...

Check your plug gaps, especially on the lower plugs. Weak spark combined with minimal plug gaps will cause some misfiring. Your plug gaps should be .015 - .019". You can usually run the upper plugs at .015", but will want to open up the lower plugs to .019".

-Cub Builder
 
Last edited:
Cold cylinder check on each mag. Sounds like a plug or lead bad on each mag, but on different cylinders for each mag.


Sent from my iPad using Tapatalk
 
Used mags. 200 hrs, but they are old Slick 4201s. I’ll check internal timing, but I may get new anyway...I have enough wrapped up in this project...why skimp on mags.
 
I also have to a C85 sitting around with a set of Bendix S4RN-21s complete with Harness that I could put on there.....Them are the good mags. I may do that tomorrow.
 
Dan, check the lead placement from the cap to the plug. Sounds like the leads aren't headed to the right plug. Also, did you time it with the pin in the right hole?

John
 
What is the air temp? O-200 carbs are notoriously lean at mid power settings. Try a full power runup.
 
Hardtailjohn said:
Dan, check the lead placement from the cap to the plug. Sounds like the leads aren't headed to the right plug. Also, did you time it with the pin in the right hole?

John
Click to expand...
Well, I feel dumb....I had top lead wire crossed on left side after I removed them the other day to re-route through my baffeling....oops....I also had a bad plug on the right side.....I replaced 4 plugs because I had 4 new plugs....Thanks for your help.
 
cubdriver2 said:
Never heard that before and never had a problem like that?

Glenn
Click to expand...

Perhaps notoriously was too strongly worded but it has been an issue over time, most recently experienced with a Cessna 150. It just didn't like partial power (15-1900 RPM) in the winter.
 
Dan Gervae said:
Well, I feel dumb....I had top lead wire crossed on left side after I removed them the other day to re-route through my baffeling....oops....I also had a bad plug on the right side.....I replaced 4 plugs because I had 4 new plugs....Thanks for your help.
Click to expand...

Well....guess how I knew to suggest that? :roll::wink: It happens!!
John
 
You must log in or register to reply here.

Similar threads

L
O-320 trouble
Replies
13
Views
4K
skywagon8a
skywagon8a
T
Backfire???
Replies
14
Views
4K
teeweed
T
B
J-3 ignition noise
Replies
16
Views
6K
wireweinie
wireweinie
supercub
Primer Line routing through firewall ??
Replies
6
Views
2K
Grant
Grant
S
Mag Switch
Replies
2
Views
2K
Frodo
F
Back
Top