250R Still Smoking???

[markdb420]

Well, my 72mm head gasket came in so I slapped it in, ran it at idle and it is still doing the white smoke. Gave it a little gas and the smoke is still coming out. Let it warm up before any testing under throttle. Ran it about 15 minutes and shut it down to check the plug. It was dark brown and not too dry, but not like it was when the head gasket was leaking. I opened the radiator cap and it had pressurized. Could it be something in the water pump? I just changed out my right side cover about a month ago and the bearings seemed fine and the impeller was almost new. What in the pump could be bad? There isn't anything coming out of the weap hole. The head is flat and so is the top of the cylinder. I'm stumped. Maybe I am overlooking something?

Any ideas?

[New2ATC]

maybe you have too much oil in it.. is it a 2 or 4 stroke?.. sometimes when you have too much oil it will smoke alot untill the oil is cleared out...

[markdb420]

it is a 2 stroke and I am running 50:1 mix ratio with synthetic.

[New2ATC]

try running with less oil.. i am not positive.. but i know that when you run it with too much oil in the gas.. it will smoke like a chimney...or maybe you have some grease in the exhaust, and its smoking alot because f that.. but then again, i am not a professional..

[timex69]

get it some nicorette it helps lots of people quit smoking j/k..try running less oil in your mix

[short4stuff]

hmm i dont know. 50:1 is pretty lean on oil, dont go any leaner than that, just try running it a bit more, maybe it is burning the left over stuff in the pipe off.

[markdb420]

Well it is real white-white smoke. I was thinking that somehow their might be the waterpump pressurizing the water cooling system, and somehow getting water into the cylinder. Should the coolant system but undre great pressure like that?

50:1 is fairly lean, but if the smoke was blue I might try a leaner mix.

I am suspecting the cooling system, maybe the radiators? White smoke means water right?

[compaqkoci]

white white smoke is usually too much oil in the mixture. or maybe mass ass steam? if its stream put your hand by the opening of the muffler and see if you get condensation on your hand if not its too much oil! take you carb apart and clean it it did that too mine when i had my carb gross. also water in the cylender will do that put that may be some left over in there from the raditor?

[trikeman]

is your case gasket good? mine was doing that , because i had a small leak in my gasket, and oil was getting into where the crankshaft is, which got into the cylinder, and made it smoke horrible...

[markdb420]

Are you talking around the area where the cylinder goes onto the bottom end? It is the case gasket you say, well that will be a difficult find. Ihad a head gasket go bad and the cylinder took on some water/coolant and I had to use gravity to get the excess water out from underneath the piston. Maybe it still has some little amount of moisture under the piston?

Is the cooling system supposed to pressurize?

[TeCaTe_MaN]

what if there was water in the crankcase from the water pump it would get in the fuel and into the cylynder with it, if there is a leak in the bearings or seals it will leak into the crankcase, this in turn would also pressurize the coolant system...

[Red Rider]

Tecateman, I have to disagree with you. If the mechanical seal on the waterpump shaft is leaking, you should at least see coolant/transmission oil escaping from the weep hole. If coolant was leaking past this seal, it could only get into your transmission, not the cylinder or fuel/air mixture.

Mark, yes, the coolant system should pressurize somewhat. Are you sure the pressure relief you heard, when you removed the radiator cap, wasn't because the coolant was warm from the bike running?

[markdb420]

Red Rider, it could be. The water elbow on the cylinder head had popped out of the cylinder and I just cannot replace it because I am running 295 sleeved cylinder. I was told by several machine shops that JB weld should hold it back in place, and that the elbow is a seperate casting and it is pressed in the the head.

The JB Weld needed to be thicker to seal better, but this still doesn't account for the white smoke. Maybe once the water elbow is sealed up better it will not leak there, and if there is any residue left in the bottom of the cylinder it will heat up and evaporate or burn off? No telling.