Tweet
Dick,
Your thoughts about possible misalignment, improper clearances, etc. was my first thought, too. Great minds think alike, eh? :GoodJob: Since I had mine completely tore down I thought I had something like the height of the distributor in the clamp wrong, etc. I was sure I would find something out of whack but everything looked fine.
I think you're right on about the square cut corners, not ever a good idea for a stressed component. Interesting that your nylon key has a different shape than the one I borrowed from Greg Lamb when my brass one sheared. (sorry Greg, I'll remember to return it some day ...)
As far as run time, I'd get a total of a couple of hours out of it before it sheared off. The last time it happened I'd run it for a couple of hours and it was fine, I thought maybe the first one was just a fluke, then Greg and I launched it at Alder Lake and it sheared off when starting. I didn't realize that was what has happening and after cranking on it a few times (I thought maybe it was flooded) it happened to jam up in approximately the right place and got us out to the middle of the lake (of course) before the dist spun free and we were dead in the water.
I keep coming back to how the dist shaft bears on the shoulders of the tapered nylon key, which is a much wider contact area than the upper portion of the brass key. That combined with the square cut corners is probably why they kept shearing.
By the way Dick, if you want some spares let me know, I have enough of the HMDPE left to make a bunch of them, I'd be happy to send you a few.
Tim
Your thoughts about possible misalignment, improper clearances, etc. was my first thought, too. Great minds think alike, eh? :GoodJob: Since I had mine completely tore down I thought I had something like the height of the distributor in the clamp wrong, etc. I was sure I would find something out of whack but everything looked fine.
I think you're right on about the square cut corners, not ever a good idea for a stressed component. Interesting that your nylon key has a different shape than the one I borrowed from Greg Lamb when my brass one sheared. (sorry Greg, I'll remember to return it some day ...)
As far as run time, I'd get a total of a couple of hours out of it before it sheared off. The last time it happened I'd run it for a couple of hours and it was fine, I thought maybe the first one was just a fluke, then Greg and I launched it at Alder Lake and it sheared off when starting. I didn't realize that was what has happening and after cranking on it a few times (I thought maybe it was flooded) it happened to jam up in approximately the right place and got us out to the middle of the lake (of course) before the dist spun free and we were dead in the water.
I keep coming back to how the dist shaft bears on the shoulders of the tapered nylon key, which is a much wider contact area than the upper portion of the brass key. That combined with the square cut corners is probably why they kept shearing.
By the way Dick, if you want some spares let me know, I have enough of the HMDPE left to make a bunch of them, I'd be happy to send you a few.
Tim
I had to pull the distributor on the runner and look what I found. Might just have to take you up on your offer.
Comment