Well, this was no fun..[sm=crying.gif]
It was windy as heck yesterday so I decided to put off test flying my new Magnum/.50V1, instead I decided to get in a few ground runs at home.
Setup:
- Weston .50V1 with pipe, carefully balanced APC 9-6 and alumimum spinner
- Jett bubbleless 8oz tank
- Wildcat 10% fuel (18% oil, 80/20 syn/cas)
After a couple of tweaks richer on the low speed needle it fired up nicely, so I let it run a few seconds at a fast idle, then throttled up. Quite rich, fast 4 cycling, so immediately started leaning in until I got a steady, rich 2-cycle. Motor running strong, fast for sure (didn't get a chance to tach it), but gobs of smoke out the pipe and there was more rpm to be had yet, so I was happy with that setting for a first run. Very smooth too, so I was satisfied with the balancing. Not more than 10-12 seconds later - uh oh - sounds like BB's in the cylinder. Yikes - yanked off the fuel line to kill it.
The big end of the connecting rod has nearly disintegrated - the hole is grossly distorted and enlarged, there is a small fracture starting from both sides and the combustion chamber had a good dose of fine aluminum flake in it. Oddly, the liner looks okay, but the piston skirt has a couple of tiny dings in it.
I don't think I screwed up here - anyone have any ideas? Is this just a defective rod, or?? Of course I'm contacting the distributor but since a bunch of you guys either have these or know about fast engines thought I'd ask.
It appears that there is some kind of bushing in the big end as well. Or was.. it fell out when I opened it up. I see that the instructions say disassembly will void your warranty, but frankly if I want to take the backplate off my engine to see what's going on, I will..
MJD[sm=crying.gif]