OS61

[Dan C]

I have a new OS61 with a tuned pipe fitted to my panic.

The engine runs fine with 1 1/2 ish turns on the carb and 15% fuel

What does worry me is the amount of black/brown liquid that shoots out the other end. I dont know if this is related to the fact that at times the engine conks out. (i put this down to over a year old fuel and will be changing to technics 10% this week, it doesnt affect other planes though)

I have a enya no.3 fitted aswell.

 

It cant be beacause its a new engine as i have just fitted a new os 46 to another plane and it is a beauty to start and run.

 

Cheers for your help

 

Dan

[Delta Whiskey]

Hi Dan, not sure of the reason for the liquid coming out of the exhaust, but fitting a on board camera to my heli yesterday, showed up the same thing, I have an OS 50 SXH  in it, so want to know the answer too!

 

It's probably something to do with not draining the fuel after flying, and it's the harden lubricants, coming out after hotting up again?

[Dan C]

I always drain fuel and surely it would stop after a while, not every flight

[Delta Whiskey]

I would have thought so............hopefully someone with more experience than I, will tell us !

[Martin Harris - Moderator]

What fuel are you using - specifically, how much (if any) castor is in it?  It could be running hot and burning the castor.

 

Otherwise, if the residue is more black than brown, there might be some fretting between the exhaust and the engine wearing microscopic particles of  aluminium away which will mix with oil to form a black liquid deposit.  Check the exhaust components are absolutely tight.

[Olly Giles]

I have had the same thing with two 50 sx's. I found that putting after oil in the engines after each flying session seemed to reduce the problem. I came to the conclusion that residual fuel was eating the piston or the liner and the oxidesed metal was being disloged and blown out of the exhaust. Anyway after oil, or i fing that a squirt of WD40 worked just as well.

[Delta Whiskey]

Sounds bad than Oli ! .....................Martin.....In my OS 50sxh heli engine, I use 16% Bekra Fuel which has synthentic oils so not castor, I decided I would go that route as my first brand new performance pipe was ruined by castor oil stains ! Though looking at the stuff dripping out mine is more brown than black......

[winchweight]

Dan, as it's a new engine it sounds normal. The black brown liquid is probably oil, heavily tainted with carbon and the rubbings from the inside of the engine as it beds in. Be careful not to run it too lean at this tender stage, it needs the oil. After time the mess reduces and changes colour back to whatever fuel colour you use, and you can gradually lean off the engine.

 

Use after run oil, consider trying an OS No8 plug, the 10% fuel is probably a good idea, but ensure that the fuel has plenty of oil in it's makeup.

 

Every engine is a little different, you could strip it and look for excessive wear if you wish. I'd keep plugging on for a bit and see if it improves, but then I use SC and ASP engines mainly and they are filthy when new.

[Dan C]

Thanks for all the replys guys, i check out the early posts and all seems to be well with the engine phsically

Shaun thank you very much, im not sure why i went to a enya 3 since all my os engines have a os plug in.

Thanks again

 

Dan

[flytilbroke]

Castor and lean not very clean. Synthetic should be a good clear appearance. Still gets every thing oily.

[Delta Whiskey]

Pretty sure my heli fuel, Bekra 16, is sythenic, I'll recheck it is in a bit, as I definately got brown droplets coming out the exhaust.

[Delta Whiskey]

Easy find:

"A mixture of EDL and Klotz oils with NO CASTOR gives super clean running. Any chance of foaming in the tank has been eliminated with an anti-foaming additive"

 

So in my case, it still could be oil