russellc172
Member
- Joined
- Mar 1, 2016
- Messages
- 5
- Reaction score
- 2
I have been trying to figure out the problem with my J3 for a couple months now and am not having any luck so I thought I would see if anyone else had any ideas. It has a Continental C85-12F that backfires at idle stumbles from idle up to 1200 where it really runs rough and backfires. After 1200 RPM it smooths out a bit but doesn't develop full power. I have found a sticky exhaust valve on the #2 cylinder, a broken spring on the #3 cylinder, the carburetor halves were loose, and the seals were missing on the studs that hold the induction to the case. I have tried running with a known working loaner carburetor and I have switched the Eiseman mags to a set of serviceable Bendix with new leads and sparkplugs. All cylinders compression check over 70 and I have had all the valve springs off to check for more sticky valves and found none. I have checked mag timing several times and it checks ok. Does anyone have any ideas because I'm running out.
