Ok makes sense this is my 1st 2 stroke and all is new to me appreciate the info and help but i checked main jet again it a 250
A lean mixture is too much air, not enough fuel to go with it. The air/fuel mixture is done inside the carb with the jetting. The oil/fuel ratio is done either at the injection pump or by adding oil to the fuel. In your case it appears that with the K&N filter which allows more air into the engine, the jetting needs to be changed so the carb lets more fuel into the engine. Main Jet and Pilot Jet sizes will probably need to be bigger along with the main jet needle style or size changed. I am not an expert when it comes to tuning carbs. I tend to stay with the stock stuff to avoid that. Latebird is an expert so he can get you started in the right direction.Lean mixture is less oil n the gas and rich is more oil n the gas ?? Is that right? And i dont see any other way to put oil n other then premix
No - lean is not enough fuel to air = high temperature burn - the oil is lubrication for the crankshaft, piston and rings - a lean oil mix actually enriches the fuel to air ratio as oil displaces gas and leans the fuel to air ratio. Does that make sense? One thing I learned about two strokes (I grew up with Kawasaki two stroke road bikes): the more oil you can run without fouling the spark plug, the more power the engine will produce and the longer it will last. Being stingy on the oil only promotes unnecessary wear and at high RPM the parts run exceedingly hot! Also, most oils will not mix with alcohol, so alcohol blended fuel in a two stroke mandates the use of special oil.Lean mixture is less oil n the gas and rich is more oil n the gas ?? Is that right? And i dont see any other way to put oil n other then premix
Yes it was really quick on take off and would have to turn fuel off or would run like shit for lil bit but the weird thing is that when it happened( burning the hole n piston) it wasn't that hot and i been watching u tube video's have better understanding between u tube and all the help from you guysLOL... a mile @ WOT on a 2 stroke is a LOOONG time. Even more so if running somewhat lean anyway. After all, you DID melt a hole in the top of the piston?
A 2 stroke will run very strong when lean but they also run MUCH hotter so you have to be careful with jetting. I used to do a lot of radical hill climbing on a big bore 2 stroke dirt bike in my younger days. You always turned the fuel off when taking a break to prevent the possibility of fuel leaking while sitting around. If you forgot to turn the fuel back on and started up a long climb the bike would run like gangbusters as it leaned out just before the fuel in the carb bowl ran out and it quit right in the middle of the hill lol! Very strong but also very hot. The engine can't stand that for long.
I have been watching u tube videos all day and got better understanding of jetting rich and lean mixture all that good stuff and i ordered carb rebuild kit and piston and rings and found air box on eBay that stock n same year as mine so wish me luck lol and appericate the help i will let ya knw how things turn outIts not all that bad OP. As latebird said earlier, the cylinder probably isn't hurt. Get the carb jetted right, a stock air filter, the oil injector working or properly blocked off and a new piston and rings and you should be good to go. Even the 4 stroke manuals tell you not to run WOT for long periods. These are trail machines and not meant to run WOT on the road for miles at a time. WOT runs on the trail are fine and won't hurt a thing because you can't hold it there for long without letting up.