Alpha I drive 5.0 liter missing at full throttle

[dwolter]

I have a 1998 Chaparral 21 ft with an Alpa I drive, 5.0 liter 225 hp EFI.<br />It began to miss three weeks ago at full throttle operation, but runs fine at lower<br />throttle positions. Does someone have an idea what it might be, ignition or fuel,<br />or hopefully more specific. The boat has 318 hours on it, clean, fresh fuel in the tank.<br />The boat has been run in fresh water only. I purchased it from a person that putted <br />around many hours at an idle.<br /><br /> Thank you,<br /><br /> Chap boy

 

[orca]

Re: Alpha I drive 5.0 liter missing at full throttle

Had a lot of problems with one of these recently, turned out to be fuel problem. replaced all filters, found water in the injectors. The injectirs have fine filters around them, cleaned the filters and the motor ran sweet. With any EFI motor clean fuel is very important.