The International Cessna 170 Association

Yep!!! And I'm really greatful for you guys.

If a spring or springs were 'weak' to the extent it showed in engine performance, wouldn't it be much more prevalent and evident? Would it come and go? Would the engine performance go from excellent to shuddering and then resolve? Or would the engine performance just sort of be poor more-or-less all...

No, if a weak spring could cause such a power loss, and the associated danger, it would be negligent to fail to replace it. But, first to prove it and find it.

Hmmmm. Think that cylinder or exhaust would now be obvious on inspection?

I remember reading your post, George, to the fella who had washed his newly bought 170 and then had these symptoms. They occurred right after getting back to homebase and giving his wife a dollar ride. And then the bath, which complicated diagnosis for all you guys; it was the 'only thing that had c...

good to know. I'll have both ready.

Bruce, no question about it; a wealth of experience and knowledge here. Trying to soak it up like a sponge. I have read every thread and post that came up after searching stuck+valve and also rope+trick going back years. Tons of great discussion. Entertaining. I picked up early on the fact that you ...

Will do, and thanks.

Since this is 'intermittent,' and only after some serious cruise, and since ground operation has to this date always been flawless, I don't expect to find a visibly stuck valve. Would you say I might expect one or more to 'hang up' while propping it over slowly?

To our invaluable moderators, and all you guys watching this, and, like me, learning from it, I'm waiting for some tools I've ordered. Next Friday, after the tools have arrived, I'm set up with a local IA (we're way far away from home and our own tool crib) to incrementally attack this thing. Pullin...

Thanks Fred, but onset is always BEFORE c/h application. C/h works great. Rpm drops to 21-2200 for no apparent reason (think I've ruled out carb ice, especially after George's nice input relative to the oil pan and carb installation). Then resolves itself after 5-10 minutes of very rough (like 5 cyl...

this is great point/counter-point.

Bruce, thanks again so much for your quick thorough and thoughtful response. You brought up several questions, as did our other helpful responders. I'll try and hit them all: Yes, Bruce, 21-2200 rpm, max. And rough. Some vibration. Only 250 smoh. And that was performed in 09, so we've been flying 'e...

It's been a great summer for flying here in N.E Washington State. Haven't done as much 'backcountry' stuff as we'd have liked , but we've gotten some good local area flights in. Sightseeing. In the process, what I thought was carb ice, I now believe is a valve that's threatening to stick. My bird is...

Good start. Thank you all. George, cutting/modifying the existing, elegant yoke arrangement isn't something I would think of doing. But thanks for the drawing anyway. My point is, if we think outside the box just a bit, with a small, sheet metal job a modern com or even a com/nav and a xponder, for ...