View Full Version : WOT RPM on '92 PCM 5.8 Pro Boss
07-14-2002, 03:45 PM
I have a '92 Mariah with a PCM 5.8 Pro Boss and 1.23:1 reduction gearbox. RPM at WOT is about 4000 with 3 people and a fulltank of gas. The highest i've ever seen is 4200 with a very light load. Should the rpm be higher than that. The boat has the original OJ 14x16 3-blade nibral prop on it. I had it straightened and balanced at the beginning of the season. There is VERY little vibration. Am I overpropped, is this just the nature of this older beast, or do I have some other mechanical problem? Thanks in advance for any insights.
07-15-2002, 06:18 AM
I reach about 4400 rpm on my '90 Sunsport with a PCM 351 and the 1.23:1 reduction transmission. It too has the 14x16 3-blade nibral prop. Its top end is close to 42-mph. If yours starts, runs and pulls well, enjoy it.
07-20-2002, 10:14 PM
Prior to making any changes or alterations I would STRONGLY recommend verifying the accuracy of the tach in the boat.
10-04-2002, 11:48 PM
I have an 89 sunsport with a pcm 351 1.23:1 transmission and a 14X14 prop. I turn 4200rpm at wot. My dad has a 91 sunsport with the same set up and he turns 4600rmp at wot.
the boats run the same speed on gps, so I think that there might be some issues with the tach on sunsports. hope this info helps.
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