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Posted (edited)

I have an old '89 big bear 350 that I am having trouble with . I have cleaned the carb , install ed a new stator , pulsar coil , ignition coil , CDI box ,new plug ,  timing is dead on , and a new intake boot , compression test says 125 lbs . When I crank it over it will start , but won't run it acts as if it's either got a bad vacuum or compression leak or is out of time . If you have any input maybe it will help I am about out of ideas .  When I got it it was not firing and the guy said he had it idling and it just died and wouldn't start . I have ordered a new carb but have my doubt's it's going to help because this is the second carb I have cleaned and installed on it . Any Ideas ?

Edited by Samuel Jerome Morris
  • Ajmboy changed the title to Old 1989 Yamaha big bear 350 won't start
Posted

It sounds to me like it might be fuel starved. Have you tried manually giving it some gas or starting fluid through the intake to see if it runs?

* Topic moved to Yamaha forum and added year and manufacturer to topic title.

  • 4 weeks later...
Posted

Ok  got it firing and now it will start . Problem is it just sits and kinda idles like an engine out of time and if i touch the throttle it dies immediatly . I have cleand the carb and then pulled the carb off another one i have and swapped them it runs great on the other bike and mine does the same on this one barely idles . I have checked for clogged exhaust , made sure fuel flow is good checked valve lash and timing . I am out of ideas i think i will pull the head next and check the gasket . The compression is around 130 lbs . Im lost ! Anyone got any ideas ? HELP !!! 

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