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Broke my .50 - what have I done?!

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Old 10-17-2005, 09:37 AM
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MJD
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Default Broke my .50 - what have I done?!

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..

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Old 10-17-2005, 10:21 AM
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Default RE: Broke my .50 - what have I done?!

Well, I called Modellbau USA, where I bought the Magnum/.50V1 combo several months ago, and was told that they haven't handled them for a while and there was nothing they could or would do, they have no parts. Great guys, thanks!

So I called Weston UK directly and got a very helpful response. They indicated that as this was first run problem and that it sounded like I had done things right, so they would put it right. Now that's more like it.. so that's the plan of attack. Yeah, I have to ship the engine to them and it has to make its way back, but what are you gonna do? At least they were positive and helpful.

Sigh.. maybe I'll drop my Jett .50 on it for now and swap back when the engine returns o'ersea. I think the Jett can handle the job "just fine" in the meantime

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Old 10-17-2005, 11:46 AM
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Default RE: Broke my .50 - what have I done?!

I had the same thing happen on my first West 50. Alan at weston was great. He told me there had been a run of engines where the bushings were pressed in crooked due to a bad set up on a machine or something along those lines. They repaired my engine no questions asked
Great guys to deal with at Weston.
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Old 10-17-2005, 11:49 AM
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Default RE: Broke my .50 - what have I done?!

Alan is a good guy. I had the pleasure of speaking with him at length at Toledo last year.

No surprise he handles things well.
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Old 10-17-2005, 12:03 PM
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Default RE: Broke my .50 - what have I done?!

Well, he didn't tell me that about the bushing issue, but he did suggest that while the engines were generally excellent, now and again they have run into a proplem.

So other than the time involved in overseas transit, looks like they will be looking after me just fine! I'm good with that. The phrase he used was "no questions asked" as well..

Oh, and Bob - looks like I can get you that picture and commentary sooner than later! So it's an ARF..

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