Running on 2 cylinders

[Rich F]

Well I have a 1989 GT150. Runs but only on 2 cyl. Ok at first it appears that the right side all 3 firing, left side all 3 not firing. By the way the motors new to me. Runs but won't get up on plane. After cleaning n doing a bunch of checks I tried to run it again with no improvement. Pulled each plug n only 2 are firing. New champion plugs on the way. The current ones are ngk. Any suggestions?

 

[Faztbullet]

These have the "T" pack ignition and usually its usually the pack or timer base.

 

[Rich F]

Thank you, guess I'll need to get a manual and go from there to get the parts

 

[oldboat1]

You can check which ones are firing by clamping a timing gun to each wire. No flash means there is no pulse going to the plug being tested. First fix imo is to make sure the clips are secure and that the wire inside is contacted by the clip. If you have a continuity tester, it is easy to test each wire end to end to make sure there is proper contact.