MikeForshey
09-14-2008, 08:55 PM
Sorry for the incompetence of the title, I was going for shock factor. I am currently working on a 6.5 hp horizontal shaft lawnmower engine of Japanese make (can't spell or pronounce the name). The scooter that it is on has been sitting for a decent amount of time (6 months or better) and, of course, I started with the basic knowledge that I have. Check spark, check airflow, check exhaust restrictions, check fuel flow and clean carb. bowl... I filed the carbon off the plug and gapped it, so now it's getting a decent blending of yellow-blue for the spark, so I assume it has yet a few months left on it. The air filter is new, and the exhaust pipe is allowing for only a moderately restricted flow of air. Ok, so now for the trouble...
When I turn it over with or without the air filter on there is a flame out both ends (as shown by singed filter and smoke). I removed the air filter and the exhaust so that I could better figure out what was going on. There was a severe liquid slosh when the engine turned over, and the piston expelled unburned liquid out of the exhaust. The liquid was gasoline base, with either an oil or carbon coloring in it. I assumed carbon because of the coating on the end of the spark plug when I pulled it. I am trying not to break it down much further, and want to know if there is anything I am missing that might be a way to define what is wrong with it.
It seems to me that if there is too much gasoline making it's way into the combustion chamber (and I know that my choke is not wide open) then I either have an air blockage (not likely) or a poorly adjusted carb. So I guess my question is SINCE I still have all of my face hair and I am still tinkering with this thing, should I be looking towards the Carb as the source of my flame (air AND exhaust) or should I be looking towards the compression chamber. I know on a car the intake and exhaust should be closed off by the valves. Should it be the same here? And if so, could a poor valve seating be the cause of my flame?
Any direction would be extremely helpful, I fear that if I don't get an answer I will have to begin removing parts and see where it lands me... :confused: Thank you.
When I turn it over with or without the air filter on there is a flame out both ends (as shown by singed filter and smoke). I removed the air filter and the exhaust so that I could better figure out what was going on. There was a severe liquid slosh when the engine turned over, and the piston expelled unburned liquid out of the exhaust. The liquid was gasoline base, with either an oil or carbon coloring in it. I assumed carbon because of the coating on the end of the spark plug when I pulled it. I am trying not to break it down much further, and want to know if there is anything I am missing that might be a way to define what is wrong with it.
It seems to me that if there is too much gasoline making it's way into the combustion chamber (and I know that my choke is not wide open) then I either have an air blockage (not likely) or a poorly adjusted carb. So I guess my question is SINCE I still have all of my face hair and I am still tinkering with this thing, should I be looking towards the Carb as the source of my flame (air AND exhaust) or should I be looking towards the compression chamber. I know on a car the intake and exhaust should be closed off by the valves. Should it be the same here? And if so, could a poor valve seating be the cause of my flame?
Any direction would be extremely helpful, I fear that if I don't get an answer I will have to begin removing parts and see where it lands me... :confused: Thank you.