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Engine basics => Engine set up tips => Topic started by: okcub2015 on June 29, 2016, 05:38:29 PM

Title: Need Help on engine
Post by: okcub2015 on June 29, 2016, 05:38:29 PM
I am trying to get an OK Cub 09 engine to run. I can only get it to run in short spurts. It does not lean out and stop, it just stops.
I have a 7/6 prop and running cox fuel. Changed tank level, fuel hose and connections. Also plug. No luck Used different glo starters, no luck.
Before i start drinking, any suggestions be nice

Bruce
Title: Re: Need Help on engine
Post by: Russell Shaffer on June 29, 2016, 05:46:52 PM
Is there any chance that your engine is new?  At least never run before?  Could be that it is just tight and needs some running.
Title: Re: Need Help on engine
Post by: okcub2015 on June 29, 2016, 06:05:35 PM
Yes it is a new old engine. It will now run in short, medium steady 5 to 6 second spurts

Bruce
Title: Re: Need Help on engine
Post by: Russell Shaffer on June 30, 2016, 03:16:22 PM
I don't know how much oil your Cox fuel has,  maybe adding a little would help.  Are you leaving the ignitor on the plug to keep it hot?  Anyhow the engine seems to be improving?  If so, just keep it up until it runs longer. 
Title: Re: Need Help on engine
Post by: Mark Scarborough on June 30, 2016, 03:31:58 PM
I am trying to get an OK Cub 09 engine to run. I can only get it to run in short spurts. It does not lean out and stop, it just stops.
I have a 7/6 prop and running cox fuel. Changed tank level, fuel hose and connections. Also plug. No luck Used different glo starters, no luck.
Before i start drinking, any suggestions be nice

Bruce
That sounds like a lot of prop for that engine, I dont KNOW That engine, but for break in I would think something smaller than flight prop would be advantagous
Title: Re: Need Help on engine
Post by: Russell Shaffer on June 30, 2016, 04:16:31 PM
That could certainly be too large a prop.  OS recommends a 7x4 for break in on an LA10  which I am sure is a much more powerful engine than the old Cub.
Title: Re: Need Help on engine
Post by: Chris Wilson on June 30, 2016, 07:18:20 PM
http://sceptreflight.net/Model%20Engine%20Tests/Cub%20099.html

What you need is flywheel weight not aerodynamic resistance.
Title: Re: Need Help on engine
Post by: Bill Little on June 30, 2016, 07:21:48 PM
Big Art once told me to get a 10X3 Top Flight prop to break in my OS.35S that he had breathed on.  I would us a 6X3 prop on your Cub for break in.  Plus add some castor, the cub did need more castor in my observations that the Cox engines. And make sure you leave the ignitor on long enough.  Just my thoughts.....

BIG Bear
RNMM/AMM
Title: Re: Need Help on engine
Post by: Chris Wilson on June 30, 2016, 08:11:49 PM
Big Art once told me to get a 10X3 Top Flight prop to break in my OS.35S that he had breathed on.  I would us a 6X3 prop on your Cub for break in.  Plus add some castor, the cub did need more castor in my observations that the Cox engines. And make sure you leave the ignitor on long enough.  Just my thoughts.....

BIG Bear
RNMM/AMM
Yep, that is pretty much what the tester reckons in the supplied link.
Title: Re: Need Help on engine
Post by: okcub2015 on July 02, 2016, 02:13:40 PM
Okay thanks for info will check out smaller props aswell.

Bruce