I am new to this forum and a new owner of an 86 Trail Boss 250. I am trying to get it up and running for my wife and kids. I get it to start after quite a few tugs on the pull start (Electric Starter motor Frozen?). Runs for a minute or two and then it dies. I am not sure if it flooding out or not getting fuel.

What trouble shooting steps should I take?

 

Welcome to the forum!!!

First we need to know if it is spark, fuel or compression related. To rule out the ignition, hook up a timing light and get the engine going, the light should flash like a stobe light, and will slow down, but not stop as the engine dies. The flash should not skip a beat as it dies, it will just wait a little longer between flash untill the last flash as the engine stops turning. I hope you know what I mean!

Most of the time an engine that dies after a short time running is an ignition(spark) problem.

Let us know how this turns out!

 

Welcome to the forum!

Although it is possible to be spark related, it sounds to me more like you may have carburetor problems - especially since you say it takes quite a few tugs on the rope to get it started. Those old 250's should start on the first or second pull if the carburetor is right and the compression is good. Poor compression makes them hard to start too (anything under 100psi is very hard to start).

When you get it running, how does it act as it is dying out, and does the exhaust smell rich, and can you accelerate the quad to keep it running? Could the fuel filter be partially plugged causing the quad to temporarily "run out" of fuel?

 

i think it has to do with the air and fuael. if it takes alot of pulls it might be getting to much fuel or not enough. check your gas filter its on the gas line coming from the tank. the reason i think this may be it is b/c ifs its clogged up the gas isnt coming throguh complete for it to run non stop just enough for it to run just filling the rest of the gas line and carb up and then dying after it starts to slowly come in and just go ahead and put a new spark plug in and clean the air filter if u didnt b/c you are going to do that after a while. then if its not running and bogging out like u are getting to much gas its the carb or not enough ( jetting )