2017 Z518 with 150 Merc PRO XS 2 stroke

[ICALDUX]

Hello,
I’m only getting about 48 MPH top end speed with this motor. I’ve got a Tempest Plus 23p & an 8” Slidemaster Jack plate. I’m running the boat trimmed up to just about 1/2 on the trim gauge. Not sure of RPM’s at the moment. This is with full fuel tank, empty livewell, 3 batteries, 1 Talon & 2 boaters. I’m pushing 300 personally & front center storage full of tackle. Should I be seeing a little more speed? The hole shot is great! Would a different prop help at all? I know dropping some LB’s personally would but at 6’5” I may have to cut a leg off to lol! I’d like to be at least around 54-56. Thank you for any input in advance.

[lpugh]

Trim it up then, it probably has what you want, just let let loose
a 23 is most likely to big, but need the the max speed fully trimed out and rpm to know for sure

[ICALDUX]

Trim it up then, it probably has what you want, just let let loose
a 23 is most likely to big, but need the the max speed fully trimed out and rpm to know for sure

Thank you for the response. I’ll check it out and see what I get this week & report back. I sure hope to get more out of it ����

[mdtritn21]

If the gauge is reading 1/2 that's probably all you'll get. If the boat is on a trailer trim the motor up until it starts to run on the tilt cylinder then trim it back down until it touches the trim rams and look at the gauge and that will be max trim on that motor. Normally Mercury's won't show much more than 1/3 to 1/2 on the gauge at max trim the rest of the movement is tilt and the gauge will show that but the motor won't run there. You may be down one cylinder so you need to know WOT rpm's to tell if something is wrong. 55-56 should be where you run.

[ICALDUX]

If the gauge is reading 1/2 that's probably all you'll get. If the boat is on a trailer trim the motor up until it starts to run on the tilt cylinder then trim it back down until it touches the trim rams and look at the gauge and that will be max trim on that motor. Normally Mercury's won't show much more than 1/3 to 1/2 on the gauge at max trim the rest of the movement is tilt and the gauge will show that but the motor won't run there. You may be down one cylinder so you need to know WOT rpm's to tell if something is wrong. 55-56 should be where you run.

Thank you for the response. That’s good info I will give that a look tomorrow when I get home from work as far as the trim. I’ll be on the water in the next day or 2 to check the RPM’s & get back on here with what I see. I really appreciate the input. As mentioned it’s a 150 Pro XS 2 stroke & when I’m running on top mid to WOT I get an intermittent rattle. I’ve pulled the top cowling off and checked around. It sounds like a metal bracket that the screws or bolts have backed off & when you get the right vibration from the motor sounds like the metal is vibrating loosely against each other. Ever heard of this? Doesn’t sound like the issue guys were having with the larger Merc’s behind the lower cowling. It doesn’t do it at low speed or idling, loading on trailer just when on pad running.