nitro-smaxx

Hello, I have an O.S. .18 that i have put less than half a gallon threw and lately it has been rly hard to tune and it there is an oil dripping from the exhaust tip. I use LC3 glow plugs and 20% top fuel. I just need to know why there is oil and not any fuel dripping from exhaust?

ttoks

the oil shouldn't burn, if the oils burning your running lean so thats a good thing, i'd look for an air leak first off, seen as how the O.S .18 is known for being easy to tune it would seem to be a logical answer

nitro-smaxx

i have checked the glow plug and cooling head and they are tight...where eles could the air leak occur?

teamhex

What do you mean the oil not supposed to burn....thats what the blue trail that comes out is.........

nitro-smaxx

so its not good that the oil is dripping out...with my old 2.5r i only had fuel drip out the exhaust when it was rich. There must be something wrong with the engine because i cannot get this this to tune right and i have some experience tune them too.

CrT-RaCeR

the oil is suppose to burn but not all of it, SOME drips AFTER runing but it shouldn't while running, that means you are rich, and that blue trail of smoke is the nitro burning with some oil, some oil gets trapped in the pipe (backpressure) so i agree with you teamhex

REVO-Beat-U

Air leaks can be almost anyplace. Check your nitro fuel lines to make sure they dont have any cuts in them. Other likely areas would include around the carb, engine bearings and seals. I will be returning my OS 18 for a new engine in the next couple weeks. I have an air leak around the engine bearings and since I dont want to pull the bearings myslef, I figure its just as good to get OS to send me a new engine.

R/C Madman

My Feedback: (1)

"Some" oil should be dripping from the exhaust but, not a lot. You may just need to lean it out a bit. 1/8-1/4 turns and see what happens. The sweat spot is just a tiny bit away.

J_Bone

My Feedback: (1)

If you are running an OS engine, the LC3 plug is the wrong plug. It's too long and is for the Traxxas 2.5 and other engines.
OS engines require OS plugs that are just a bit shorter and for a reason. Use the OS #8 and A5 plugs. Those will make it easier to tune and you will see a difference. I use only the A5 in my OS .12 and .21 engines and they run great. But if your mostly bashing, use the #8. Unfortunately in my OS .18TZ I have to use the P6 or P7 since it's a Turbo head.

Hugger99

If there was an airleak and you can not iron it out OS gives a 2 year warrenty. I'd think you'd have a good case for a replacement engine with them.

ttoks

the blue smoke is mostly the burning nitro and methanol, it gets the blue colour from the oil breaking down before it burns, it burns from running to lean and temp going above the ignition point of the synthetic oil in the fuel (caster wont burn until 800 F, if the engine gets to that it's in a kilm) if it burns you get carbon build up, which practically kills the engine.