Yamaha HPDI 200HP Problem

[PhilinMD]

Purchased a Cobia 284 boat equipped with twin Yamaha HPDI 200 motors in 2000. From day 1 the motors in ocean seas drop RPM's from 2600 to 1900 while running. Sometimes they rev up on their own and other times do not. If the throttle is adjusted the boat eventually surges to 3300 - 3500 RPM's. Contacted Yamaha and they stated this is due to the boat not getting up on plane so the motors throttle down. This operation makes ocean fishing difficult and dangerous due to the engine surges in rough waters. Is anyone else experiencing this problem.

 

[rodbolt]

Re: Yamaha HPDI 200HP Problem

its common with all engines operating at a hull speed that is almost planing or barely planing. when you hit the next sea the engines are overwhelmed and RPM drops. kinda like going up a steep grade in your truck without applying any throttle. speed and RPM will drop as the grade is climed and rise coming down the grade if no throttle adjustments are made. only thing to do is buy a more suitable boat for rough seas or pick nicer days or throttle up.<br /> this is assuming that the engines are in proper operation and propped correctly. you may try 2-3" less pitch to allow more RPM for the same hull speed. kinda like changing gears on your truck. just now you must be careful not to overspeed the engines with to much throttle.<br />same as running in second gear in your truck, will work fine at 20MPH but not at 50 MPH.

 

[JB]

Re: Yamaha HPDI 200HP Problem

Duplicate post. See Outboard Non-repair.