The Cessna 120-140 Association Forum

I’m due for new plugs and ignition harness. In trying to wrap my head around what I need to do, I’m a little worried getting the back plate off the mags to swap out the harness. With the O-290-D up front I don’t have a lot of firewall clearance. Has anyone attempted this before? On another forum someone asked if the engine can swing out like a cub or 185, but I’d didn’t think that was possible.

Any tips?

My mechanic looked things over on my new to me bird during it's first oil change. His thought was that we'd probably need to get an engine hoist, loosen up engine mounts and pull the engine forward a few inches to work on the back of the engine.

Probably not what you (or I!) want to hear, but we just need to remember how nice it performs!

Well after 7 hours of fiddling, squeezing and swearing, I finally got both off and replaced! I don't have access to an engine hoist, so that wasn't an option for me this go around.

8359 wrote: ↑Mon Jul 29, 2019 11:19 am Well after 7 hours of fiddling, squeezing and swearing, I finally got both off and replaced! I don't have access to an engine hoist, so that wasn't an option for me this go around.

Congrats and hats off for what had to be some incredible patience and "finagling"! ...really tight back there, for sure. It sure appears that you came very close to the impossible ! Mac

Next time, consider renting a hoist, or, I've also suspended engines from the ceiling joists long enough to move things around. Another option is to build a giant saw horse and hang it from that.

2066 wrote: ↑Mon Jul 29, 2019 12:06 pm Congrats and hats off for what had to be some incredible patience and "finagling"! ...really tight back there, for sure. It sure appears that you came very close to the impossible ! Mac

Thanks! I have a little bit ratchet that made life easier getting those screws off, but they are flat heads which doesn't help the case. I do wish I changed them out to a socket head cap screw, or something a little easier to work with.

6643 wrote: ↑Mon Jul 29, 2019 12:39 pm Next time, consider renting a hoist, or, I've also suspended engines from the ceiling joists long enough to move things around. Another option is to build a giant saw horse and hang it from that.

Yea, I've always followed the theory that it's easier to take things apart a bit to make your life easier, but not having access to a hangar, and no longer having my truck makes things a little more difficult. I think I'll definitely try a little harder to do it right next time.