Hi,

I've just pranged my 46 LA[:'(], and after running in again to re-calibrate, I noticed that there appears to be a leak in the rear left area of the head, just next to the screw. The engine also 4-strokes at idle, but maintains a consistent idle, and dies after a 2-3 period of full throttle. I'm running a 10.5*8 Bolly, and 10 nitro[sm=cool.gif], 20 coolpower and 70 meth.

Any idea what the problem might be[sm=confused.gif].

Seem to think that I may have blown a gasket, but the engine does have one.

John Murray

I am looking at the exploded view of the MAX 46LA and it shows a head casket . I used the back plate gasket from this engine for my OS .40LA and don't have any problems as of now. GL

Just a thought, but you said you were running in again. Did you strip the engine at all to check it after the crash? If you removed the liner did you line up the locating pin at the rear? One way to check for a compression leak is to up end the engine in a bowl of water so it covers at least the head and then turn the crank to TDC and hold it there. Any leaks from the glow plug or head seating area will show up.

I went with the idea that the cylinder head may not be fullt tighten, so I removed the head, cleaned out the screw holes, and the inside of the head, and re-assembled. I then flipped the engine into a bowl of meth, and cranked it over, nothing!!!

Seems the head was all the way down, thus not creating a proper seal.


John Murray

John
So I take it that you've fixed the problem? I hope so cos that'll save a call to Model Flight
The trick with tightening the head screws is to just barely feel them nip when you first put them in and then tighten them in a cross pattern in very small stages. If you put in the first screw and do it up too tight it'll tilt the head and chances are it won't seal properly.