motor won't get up to full throttle?

[jpl]

not really sure how to wrod all this but here goes...went out on ocean yesterday everything went great...stopped to fish again..started engine back up..never could get it up past 8 miles an hour...throttle all the way down...changed plugs next day..same problem...we have a 90 horse yamaha...runs good at low idle..can anyone suggest things to try before taking it to the shop.thank you...jpl

 

[dpruett]

Re: motor won't get up to full throttle?

iwould start with the control cables runnig from the console back to the engine. making sure that all are connected. possible the carb. linkages have come diconnected

 

[jpl]

Re: motor won't get up to full throttle?

had my wife run the throttle lever while i looked at the linkage to the carb..the carbs are opening wide open so linkage seems to be working fine

 

[BKool68]

Re: motor won't get up to full throttle?

A number of things can cause poor performance from water in the fuel to a dead cylinder. Try pulling one plug wire at a time to see if any doesn't change the motor RPM's while running. No change would indicate a cylinder that is not making power. If you find a dead cylinder then check that cylinder for compression, spark and fuel to find out the problem. Good luck.

 

[jpl]

Re: motor won't get up to full throttle?

bk 68....thank you so much...seems we have a bad cdi unit...gonna fix it and go boating thanks again...jpl