Help On Update

[MDean89]

2003 18' H56
2003 Optimax 135L - 20" shaft
6" Pro Hi-jacker manual jack plate
Hot foot
Recently raised ob to 4” ptp
Power Tech 13.5" 19P ss four blade (not sure how old)
42 mph gps wot at 4950 rpms trimmed out a little until porpoising starts.

All cylinders firing and compression good. I never paid much attention to the performance until recently. Seems I should be getting more speed and rpms from boat. Gotten alot of suggestions from other threads on BBC - raise engine, lower engine, remove jack plate, try this prop that prop, compression test, move load in boat around. Tried moving more weight up front. Tried a 23P power tech 3 blade. No improvements with either. Recently raised ob to 4” ptp still with the 19P four blade, no improvement. Any and all suggestions I gather are appreciated.

[Jessxpress]

Still to deep. Go to 3.5. Do you have a water pressure gauge? I run mine up until I loose pressure at about 2.75”. Boat comes alive above 5000rpm. Your prop needs to raise the bow and the stern

[jgleu]

Maybe get away from powertech props and try a different one. I ran a 25p tempest on my 2011 H18 with a 150 vmax and hit 70 mph at 5900 rpms. Now I have a 2020 X21 with 200hp flashed to a 300 and using a 27p tempest. I got it in the upper 70's but ran out of running room (I was in Toledo Bend and the wind was crazy so I was running it a spot that didnt have much winds. I plan to go run it again soon.

[Tim Kelly]

25" shaft? That would be an XL shaft outboard.

[MDean89]

25" shaft? That would be an XL shaft outboard.

Correction, 20". Thank you.

[croix-man]

I had a 2005 Merc 135 opti on my 2006 X19, I believe I was running a 25 trophy at 3.5" below pad and running in that 50-52 mph area.