boat won't plane out

[1987stratos189v]

Hi I have a 1989 200hp evinrude xp "stlccm" model and it will not plane out. Powerpack dosent even have 3 hours on it. Carbs are clean. I'm totally stumped and have a tournament next week. Boat starts good idles good with a little sneeze from time to time when cold starting. The stuttering when I try to get on plane is the big problem. When it runs right its a beast problem happens after about 10 min of driving or if I stop to fish then restart. HELP.....Thanks

 

[racerone]

Check to make sure it has spark on all 6 leads .----Check shift interrupt switch too ( if equipped ) with that.

 

[Docksidemarineservices]

If the engine is running too smooth at idle, there is a good chance it is only running on three cyl. As racerone said check for spark on all the holes.

 

[Boobie]

Do a cylinder drop test on it when It's running to see which cylinders aren't firing.

 

[1987stratos189v]

All cylinders are firing. DO you think its a coil problem as it happens under load? Once in a while it'll jump on plane then sluggish to plane out and no top end cosistently 50 mph, boat will do 73 when its running well.

 

[racerone]

Try this.-------Run with a timing light hooked up and see if you are loosing spark when motor acts up.----Light will go black when there is no spark.-------And have you inspected the shift interrupt switch if the engine is equipped with it ?

 

[Boobie]

You have to trouble shoot it when it's acting up.