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Dominick
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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I have a yamaha 200 vmax hpdi year 2004;runs fine in

Customer Question

hi, I have a yamaha 200 vmax hpdi year 2004;runs fine in neutral,suddenly looses all power for a fraction of a second when in forward with about 3000 rps or more , this continues,on off on off,feels like fuel flow is suddenly cut of for a moment,just to be restored the next. over a certain speed.have checked external water separator and internal fuel filter,have also checked quality of fuel from vapor separator tank
Submitted: 2 years ago.
Category: Boat
Expert:  Noel Schembri replied 2 years ago.

Hello my name is ***** ***** I will assist you. Are the gauges going down during the power loss or just the engine looses power. If the gauges are going down then you would need to check the battery terminals on both the engine and battery side. Come back to me with your feedback.

Noel

Customer: replied 2 years ago.
gauges are going down when power goes down , battery terminals on both battery and on engine is properly connected, i just tested it ,first it ran ok for a couple of seconds even on full speed 5700 rpm, then it started to quit for a fraction of a second,then it worked again then quit again,then worked again,then quit even on 2000 rpm when I gave throttle,then it stopped, I started it again, gave pawer 2-3000 rpm stopped again and so it went on and on
Expert:  Noel Schembri replied 2 years ago.

Ok so problem is definitely electrical related. At this stage i suggest you check the ignition switch for any loose connections / corrosion and also the harness that goes to the control box. Check the connection inside the engine to be properly tight.

Keep me updated on your findings.

Noel