trdexter

Ihave a OS 61 2 stroke, after about 5 minutes of flying i can't full throttle if i do it will just go to idle, then i have to go to idle to get the throttle to pick back up again, the engine is extremly hot, i have tryed to set it up. It seems to idle good and I have removed the high end needle valve and blew fuel into the carb from the preasure side. Could my low
end be to lien ???

onepern

could be a number of things High end to lean bad fuel line sucking air or collapsing or the clunk sucking up to the back of the tank.
Danny

trdexter

I don't know if it's any of those things it has new fuel line and I use to get good smoke on another plane I had it on. How ever while I was fitting it for the cowling
I've removed the head and carb. I didnt think about the air line collapsing. I'll pull the tank and replace all the fuel line, clean the clunk,
replace the o-ring in the needle valve and seal all removeable contact points like the head carb and slim line pipe with high temp rtv.

TexasAirBoss

My Feedback: (22)

Cowl ? Do you have at least twice the exhaust area as inlet ?

trdexter

What???

onepern

do you have the right size muffler

Flak

My Feedback: (1)

What fuel (nitro/oil content) and what glow plug are you using? I would think 10% nitro/16% castor would be good and an OS #8 glow plug. Good luck.

trdexter

The muffler was bought for the engine, and I run #8 glow plug and 10% omega pink. The only thing that has changed
on the engine is the muffler. I am almost wondering for some chance I'm not getting enough compression to the tank.
I wonder what might happen if I plug off one of the exhaust ports. I've also tried other glow plugs.

Phlip

Allow me to help clarify what (I think) PioltFighter meant: You said you have this engine in a cowl. It's important to make sure that there is enough cooling air-flow through the cowl. In order to accomplish this, it's a rule of thumb to have twice the area of warm air outlet, at the back of the cowl, as you have cool air inlet, at the front of the cowl. Otherwise, the cowl gets full of hot air that has nowhere to go, so the engine overheats.

Phil

campbec

Hi trdexter,

Further to what has been said in some cases just having the exit to the cowl twice the size of the inlet may not be enough if you are not generating enough air flowing past the engine. This problem can also be exacerbated by having an in cowl muffler which adds to the heat build up. If the cowl openings are of sufficent size and the engine is running slightly on the rich side and still overheating you may need to build in a shroud inside the cowl to ensure the air is directed to flow past the motor.

Cheers,

Colin

trdexter

The head side of the cowling is totally cut away on that side.