The International Cessna 170 Association

Turned out not to be anything to do with the harmonic balancer (only piece of good news in this fiasco)!

The mag was inspected and came back working, although "nothing was found".

The fix ended up being washers: viewtopic.php?p=153369#p153369

Hi All, Finally fixed ... Yes only last weekend did I finally figure out what had caused this. This was a post https://forum.cessna170.org/forums/viewtopic.php?p=145364&hilit=engine+mount+to+firewall#p145364 about replacing the firewall-engine frame bolts. The spacers that Jim showed in that thr...

Thanks all for your various suggestions and stories. I am (understandably I think) leaving the harmonic balancer possibility to last as it involves pulling at minimum the exhaust on one side and removing cylinder 1 or 2 to have a look and see if the balancer is stuck. It is unlikely I would be able ...

Hi all, I am still searching for the cause of the harmonic vibration in my 170. Previous discussions led me to valve springs which turned out not to be the problem. Here's a quick update: 1. Replaced the valve springs 2. Replaced the ignition system: mags, harness, plugs. (Mags were hosed). 3. Check...

Thanks George, I continue to be amazed at the database of SBs, ADs, STC, etc. that you seem to have memorized! I'm not concerned that the spring is missing - obviously it's in compliance with the SB. It's more I'm nosey and would like to know why it's been removed, what it's function was and why is ...

Hi All, I purchased a 10-4895-1 (overhauled) to replace my 10-3237 and it came with safety wire where the throttle spring is on the old one. I saw something written about ensuring you safety the screw when removing the spring, but that was for a different model. I remember during training being told...

Hi Arthur, The tail pull handles are IMO required equipment! I couldn't manage without them; and don't need a tailwheel truck/tug as a result of having them. Don't install it until you are sure you're finished crawling down the back as it is difficult to reach/crawl past. Inspection hole: Here is th...

For reference, in case anyone else runs into this. In consultation with Champion I drilled and reamed the holes in the clamps out to 10mm. This gave adequate clearance to install the mags. It turns out the slots in the Bendix mags are 9.7mm wide for a 5/16" stud allowing about +/- .9mm toleranc...

Thanks Bruce, I put the cotter pin on wrapped over the way they were on the Bendix; there is nothing behind that they could foul on. However, I'll replace them the other way for the sake of your neck hair! :D The posh flangey nut came with the kit! I have a support call into spruce, so we'll see how...

Thanks Gary! That's some excellent dot joining. I sent a support request to Champion Aero (Slick) yesterday and now to Aircraft Spruce as I've not heard anything from Slick. I'm adding this info to both and I may go ahead and order the $10 ones from eBay in the hopes of getting things moving! I also...

Hi All, Having sent my Bendix mags for inspection, it turned out that they needed complete overhaul. The harnesses were shabby too, so I decided to bite the bullet and order the Slick Kit for the O-300: K6327R-40 I have successfully installed the gear onto the magnetos. The mags insert into the acce...

Update - yes the saga continues! I replaced all the valve springs. The previous springs were in good condition and while I have not measured them, I have no reason to believe there was anything wrong with them. As the weather turned cold and wet here the problem started happening on the ground and e...

I don't have the old logs here, they're at the office so can't check if the pots were new or just refurbished at 568. I'm assuming they were new at the major overhaul now 720ish hours ago. I don't have the overhaul paperwork from that overhaul, just the old log book so no idea what the clearances we...

When I bought it the engine time state was: Total time 3204 SMOH 702 STOH 568 However it had been on a C172 that rolled over in a storm when not tied down properly. It caught the prop on a kerb which bent the crank out of spec. The engine has been rebuilt with a yellow-tagged crank ground 10 thou un...

Hi All, I have a problem with vibration in flight. I’ve tried various things to rule out possible problems as described below and I would appreciate any feedback or ideas. I have not flown any 170 but this one, nor any early C172s with the O-300 so I have no feel for what it’s performance should be ...