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  • March 29, 2024, 03:40:28 AM

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Author Topic: Brodak .40  (Read 119 times)

Offline Perry Rose

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Brodak .40
« on: Yesterday at 04:16:49 PM »
I won the engine in a raffle. I broke it in as required in the instructions.  It starts easily but at the end of a flight the prop stops as if the engine is seizing. When hot the prop is dragging as if it's cold and castor left over. When it is cold the engine is much looser. I didn't want to but I took it apart, removed the crankshaft and polished it with 2500 and 3000 grit paper. I think that will end the tightness when hot. One run on the bench shows some promise.
I may be wrong but I doubt it.
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Offline Robert Zambelli

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Re: Brodak .40
« Reply #1 on: Yesterday at 08:25:02 PM »
What fuel are you using?

Offline Dave Hull

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Re: Brodak .40
« Reply #2 on: Yesterday at 10:23:39 PM »
I have related this before in perhaps more detail, but the short version is that the symptoms you cite also match a known issue (at least with the Brodak .25):

If the case and/or muffler interface has not been machined or lapped it will distort the piston/liner fit. It may feel nice when cold, but once run, it starts to bind up. Check your case and muffler. We lapped the muffler on my friend's engine and the problem went away, and the engine did not appear to be damaged. It probably had less than a dozen runs on it before he stopped to figure out what was going wrong.

Dave


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