My repair shop doesn't know why I'm, only getting 3100 RPMs at WOT on my 30 HP mariner. I understand I should be getting around 5500. We did eliminate a few issues while trying to figure out my poor perfomance issues. He rebuilt the carbs so I know that is clean. I have good compression and spark in both cylinders. Fuel does not seem to be the issue. The prop was pretty dinged up so I replaced that. The diameter an pitch seemed to be appropriate for that moter according to 3 sources. I replaced the impellor. All season I've been trying to increase the top end speed of my boat. I have a 15 foot sylvan that tops out at around 7.5 mph and will not plane with 2 guys and a full tank of gas. With a light load I can get it to 13 or 14 mph. When the shop hooked up the timing light it revealed the 3100 rpms. Does anyone have any other suggestion i could try to increase my speed. I was told I should easily get a top speed in the low 20 mph range with 2 guys.
Attached are some photos:
Attached are some photos: