Yet another engine question....

Cajun66 Tue Feb 18, 2014 8:21 pm

I disassembled my OS46 CL engine after my plane had an inverted conflict with the ground last Sunday. THe venturi was packed with mud to I completely disassembled the engine entirely, thoroughly cleaned it, then oiled and reassembled it. Here's where I messed up: I forgot to pay attention to the position if the hole in the spray bar. It's a single hole that does not go all the way through the bar. I have it in with the hole pointed at the sleeve valve at the moment. And I haven't tried running it yet.

Cajun66 Tue Feb 18, 2014 8:31 pm

I think I can almost remember seeing the hole in the spraybar before. I may have it 180 out.

**RknRusty** Tue Feb 18, 2014 8:48 pm

I locate mine so that can barely see the hole on the rear side as you look down the throat. I don't think it's terribly critical.
Rusty

Ken Cook Tue Feb 18, 2014 9:23 pm

This is very simple and OS usually provides flats to assist you in the install. The hole wants to follow the same angle of the venturi stack. You could also slightly favor the hole towards the back rather than have it directly centered on the case. It's said that higher vacuum pressure is developed. Personally, I just follow the same angle the case is. Fox spraybars use a two hole setup and I know of no current needle doing so. Matt, may I add a additional note here. Seeing you removed the backplate, this can cause problems at some point that can be difficult to diagnose. The plastic backplates are notorious for case leaks. They seem to be more prone to this when taken apart. I like the plastic back plate, however, they can break and they can also leak if not torqued properly. Placing a #4 washer under the screw heads works very well. In addition, a little RTV is another good choice as it seals well and can easily be taken apart if needed. Ken