496 HO miss?
 

I set out to test a diff prop yesterday and all seemed well when i fired up the motor and then idled out to the channel. It is a pretty good distance to the channel, no wake zone, and by the time we were close I thought something sounded different. Trying to take off there was loss of power and miss sound. After screwing around trying to look and listen for about 5 mins everything ran normal and I made several passes with no probs. Question is will all the electronics and alarms on that motor wouldnt there be an alarm for a situation like that. Plan on going through all the plugs and wires tonight.

Have it scanned. Mine did the same thing; would sometimes hesitate on accelleration right off of idle when it was cold. I ran it this way for maybe 20 hours without problems, but running up the lake one day the soft alarm started (2 beeps every 2 minutes). Turns out it was the IAC valve. Replaced that and it ran like new again.

Hopefully the shop can get it scanned tomorrow.
As of last post boat has been out of service,, Rough Idle and No power. POS ruined my weekend. LOL

If you have no alarm, then I would suspect you have a boost pump dying on you. IAC's, MAP sensors etc. will give alarms. Typically if no alarm then there's a fuel issue...Assuming plug wires and plugs are fine that is.

if you have denso plugs, replaced them w/ ac delco or ngk no matter what they look like. we had a run of 496s with idle/miss/power problems and no codes and plugs were usually the culprit. good luck