Mariner 8hp 2 stroke running for 10 seconds and cutting out. Think it’s only running on one cylinder. Any help?

[Levbar0640]

Motor shakes ALOT and only runs for about 10 seconds then cuts off. Have had a buddy tell me only running on one cylinder but I wanted to see how much that would cost me.

 

[racerone]

I can not see your motor.-------Need to post information.-----Post compression values.-----Does spark jump a gap of at least 5/16" ( 8 mm ) on both leads?-----Could be a simple as needing a new sparkplug as well.

 

[Levbar0640]

I do not know about the spark but, the compression is 122 and 125. all new electrical.

 

[racerone]

Post results of a spark test.-------I can not touch or see your motor.

 

[flyingscott]

Is this a Mercury or Yamaha built motor?