1994 200 HP - engine won't rev > 3000 RPM

[SmokeBringer]

I have a 1996 Angler with twin 200 HP Suzuki EFI engines. These engines have low hours (approx 250 hrs) and have been recently compression tested - all OK.<br /><br />So a couple of days ago I took the boat out and the port engine would rev up to about 3500 and then just throttle back to around 3000 RPM. The starboard engine was and is operating flawlessly. After about 15 minutes the port engine started behaving fine and we ran the rest of the day with no issues.<br /><br />The next day out I had the same problem. Same 15 minute period followed by all OK except that we stopped for lunch and after about 2 hours I fired um up and I got the same behavior. Port engine rev to 3500 then slide back to 3000. Again after 15 or 20 minutes the problem went away.<br /><br />The third day out the port engine always behaves the same revs up and then backs down to 2700-3000 RPM. This time though it doesn't get better after running.<br /><br />SO my analysis:<br /><br />Dirty fuel - not likely since starboard engine OK<br />Blown powerhead - not likely since it was working intermittently<br />EFI computer - not like since it is intermittent<br />Throttle - I checked the mechanical and all seems OK<br />Short in firing (plugs) - possible?<br /><br />Anyone have any other theories?

 

[Steamboat]

Re: 1994 200 HP - engine won't rev > 3000 RPM

Sounds like the rev limiter is engaging after the engine gets warm. Are there any alarms or idiot lights lit on the engine monitor gauge? Could be overheat, oil flow, water flow problems and the engine monitor just isn't working correctly but the engine is rev limiting to let you know there is a problem.

 

[SmokeBringer]

Re: 1994 200 HP - engine won't rev > 3000 RPM

No alarms are visible so my assumption is that is isn't a "standard" failure mode like low oil, hi temp, etc. Also the problem was more like it was acting funny cold instead of warm. First couple of times, it occured when the engines were cool and the problem went away after about 15 minutes of running at reduced RPM.<br /><br />Do these engines have a computer port that might show something that would not necessarily show in an alarm light?