46 FX tuning problems
 

I just got a brand new 46 FX and I am having problems getting it to run properly. When I first started it from day one, from idle, it was very slow to pick up to speed. After I was adjusting the low speed setting I finally got it to come up to speed properly, but to do this the low speed screw had to be only 3/4 of a turn open from the closed position. The manual states that factory setting is 1 1/2 turns. This seems a lot to me. Then next problem that I have with it is that now that I can get it to come up to speed correctly is that after a minute or so of flying the engine starts to surge. Almost the to point that it sounds like it is ready to cut out. This problem I haven't been able to correct. I am lost for a solution. By the way I am running an 11x6 prop using 15% Morgan Omega fuel.

Any help would be appreciated.

Thank you

RE: 46 FX tuning problems
 

Did you post this twice ?

RE: 46 FX tuning problems
 

ya I posted it in the OS tech support section. Yes I know that you are not supposed to duplicated posts. Sorry

RE: 46 FX tuning problems
 

I don't know if you can't post twice or not so no problem , But I answered the question in there and Hobbsy deleted it which is RCU policy for manufacturer post.

But to give you some tips, the instructions say "Open the needle-valve to the advised starting setting and start the engine. If it stops when the glow plug is removed open the needle valveto the point where the engine does not stop.

When breaking in my engine I opened it 3 turns and continued following the instructons.

Good Luck.

RE: 46 FX tuning problems
 

It sounds like it is leaning out too much when it gets hot. Richen up the
main needle 4 or 5 clicks. It may be a little rich at first, but after a minute
it will be good....you don't want the engine over-heating.

You have it over propped as well....another reason it is over heating. [:o]

FBD. ;)

RE: 46 FX tuning problems
 

Flyboy Dave I have also used a 10x6 and 11x4 and it does the same with these props also.

RE: 46 FX tuning problems
 

Flyboy Dave where do you fly I am pretty close to San Ber. Maybe we could get together?

RE: 46 FX tuning problems
 

Killer,


Your engine must be broken-in properly, before you should expect it to idle and run properly.
Please follow [link=http://www.rcuniverse.com/forum/Tapered%2DBore_Engine_Break%2Din_%2D_Upgraded/m_1850473/tm.htm]this RCU thread[/link], for the correct procedure, and see what OS have to say in [link=http://www.osengines.com/faq/product-faq.html#q2]their own Q&A page[/link].

The procedure stated in the 'generically written' manual that you have, is incorrect and has been 'disowned' by the OS 'brass'.


FBD, after the break-in is completed, I cannot agree that a 11x6 prop can be considered 'over-propping' this engine.
In flight, this prop size will fly the model a bit more slowly, but speed loss on vertical and ascending maneuvers is much reduced. Prop braking on steep landing approaches is significantly increased also.

In fact, props as large as 12x7 are deemed suitable for this engine, if the manual and Tower's web page can be trusted on this issue.