Saturday evening I came across what appeared to be a good deal for a 1998 Trail Boss 250. The previous owner has had it since the showroom floor. It ran great for him from that point up until last fall. A family member was riding it down the trail and it up and died on her. Has not been able to get it to fire since. They replaced the top end, still could not get it to start. They threw it up on the local classifieds for $300. I was the first to respond, and now its mine.
Knowing the top end had been rebuilt, I brought it home thinking that it was something electrical, or fuel related. Got it home and immediately began to tear it apart. Pulled the plug out, ground it to the motor, and pulled the rope. Got spark.
Put my thumb over the spark plug hole, and turned the engine over, blowing my thumb off the spark plug hole. Appears to have enough compression to start.
Moved on to the gas tank and carb. The tank was all but empty, and the carb looked like it needed some TLC. Pulled it off, cleaned the main and pilot jets, cleaned the slide, the throat, and put it all back together. Drained the rest of the tank, cleaned it out and put fresh premium in it. Put it back together, pulled and pulled and pulled. Nothing. Hooked it up to my car to allow the starter do the work. Still nothing.
Checked the throttle cable for proper adjustment, unplugged the ETC, nothing. Key switch, and kill switch seem to work as normal.
After several minutes of holding the throttle wide open, full choke, half choke, feathering the throttle etc. I was at a loss. Pulled out the spark plug and poured a small amount of premix into the cylinder. Still nothing.
I decided to pull the pull rope for a while, one of those pulls, the engine stopped like it was seized. After a little persuasion, it finally turned freely again. It only took maybe a 1/4-1/2 rotation for it to spin freely again. I do not believe the engine to be seized because it now turns freely again.
I know this is a lot of info, but any ideas? Is it possible that a skirt or a ring is down in the bottom end banging around in there? Would that keep it from starting though? FullSizeRender (17).jpg ,
Knowing the top end had been rebuilt, I brought it home thinking that it was something electrical, or fuel related. Got it home and immediately began to tear it apart. Pulled the plug out, ground it to the motor, and pulled the rope. Got spark.
Put my thumb over the spark plug hole, and turned the engine over, blowing my thumb off the spark plug hole. Appears to have enough compression to start.
Moved on to the gas tank and carb. The tank was all but empty, and the carb looked like it needed some TLC. Pulled it off, cleaned the main and pilot jets, cleaned the slide, the throat, and put it all back together. Drained the rest of the tank, cleaned it out and put fresh premium in it. Put it back together, pulled and pulled and pulled. Nothing. Hooked it up to my car to allow the starter do the work. Still nothing.
Checked the throttle cable for proper adjustment, unplugged the ETC, nothing. Key switch, and kill switch seem to work as normal.
After several minutes of holding the throttle wide open, full choke, half choke, feathering the throttle etc. I was at a loss. Pulled out the spark plug and poured a small amount of premix into the cylinder. Still nothing.
I decided to pull the pull rope for a while, one of those pulls, the engine stopped like it was seized. After a little persuasion, it finally turned freely again. It only took maybe a 1/4-1/2 rotation for it to spin freely again. I do not believe the engine to be seized because it now turns freely again.
I know this is a lot of info, but any ideas? Is it possible that a skirt or a ring is down in the bottom end banging around in there? Would that keep it from starting though? FullSizeRender (17).jpg ,