The International Cessna 170 Association

Mine do have the Bendex mags. Type S6LN-21. Overhauled 8/22. I've never had my timing drift that much from new or rebuilt mags breaking in before. I don't think I've ever experienced more than 1 or 2 degrees drift for any reason, YMMV. I think I'd monitor the points gap if the trend continues? I do...

Mine do have the Bendex mags. Type S6LN-21. Overhauled 8/22.

One of the lower spark plugs was fouled. Cleaned them then reinstalled. Still getting 120+ on left mag drop. Reset timing and now getting 75 drop on that mag. Airworx told me that it is common to need to reset timing during breakin process.

RIP, that plane sure is mangled.

Thanks, I’ll keep you posted.

Could a plug be so fouled that a 1 hour flight wouldn’t “burn it off”? Has to be removed and cleaned?

I’ve been leaning mixture to rich of peak on ground and air.

Yes, mags were overhauled and the leads are all new. Its a certified rebuild.

I’m going with to get the installer to look at it again. I’m thinking it ran properly on the dyno but maybe something was mixed up when mounting the engine.

My previous engine consistently had a 40 rpm drop on both mags.

My mechanic installed a fresh Airworx rebuilt O300A on my 170B. Initial run up had a 10-20 rpm drop on right mag and 110-120 rpm drop left mag. I’m also noticing a hair more vibration than with old engine. Mechanic said run it 5 hrs then see if it needs to be looked at. Possibly oil fouling on lower...

Those are great!

My plane was still down! Maybe next year.

Well guys, I got my sump fixed for $1500 via the spray welding process. I’m told it looks like new now.

Awesome!

I nearly ripped apart a Lycoming cylinder at the joint. Vibration was tremendous. Large crack found 3/4 around that joint. Rebuilder sent us another to bolt on. I’d suggest grounding plane for now.

FB comments by vendor say high velocity low temp filler for the magnesium sump. I’m looking into this for my O300A.

Richgj3 wrote:Checked the sump I have access to and it is the three bolt version.

Thanks, if we give up on mine then I’ll see what type I need.