So Slow Drives Me Nuts

[Drewmac]

We fish off a 24-26' Sea Cat with twin Susuki 140's both 98's, hours unknown. We have had the boat (bought used) for three seasons. The boat will barely do 25. Cruises at around 18-22. Motors have never been problamatic, sound fine, always cranked (knock on wood), but I just wondering if they might be missing a few hp's. I'm wondering if the stickers might be wrong or somebody snuck in a 1 in front of the 40. Dont have too many other boats to compare to other than an older 350 i/o that we used to fish and it would do easily in the 40's and it was an older 24' heavy deep v lake boat cuddy cabin. Really like the SeaCat, great platform, but just takes half the day to get around places. Is this normal speeds for this cat with this power? Thanks for any opinions and hope I got this in the best place.

 

[External Combustion]

Re: So Slow Drives Me Nuts

Waterlogged foam? Engines trimmed up/down too far? Props correct? Just some of the common points on the outboard performance checklist.

I'm sure others will expand it. Good luck. It does seem a bit slow for the length.

 

[MikDee]

Re: So Slow Drives Me Nuts

Wow 280hp combined outboards on a 24' Sea Cat it should do at least 40-45mph IMO, if the engines are in decent running shape? I know you say you've been runnning them this way for 3 yrs, not good if you're lugging the motors, don't know how much power is left in them? Anyway, your props maybe too deep in the water, setting engine height up on a cat is tricky. Normally I'd say make sure the cavitation plate is just even with the height of the hull bottom, to begin with, How about some numbers to help us out, like full throttle rpm's, and what prop pitches you're running,,, a few pics of the motors mounted on the transom, would be good also.

 

[fishmen111]

Re: So Slow Drives Me Nuts

What RPMs are you hitting? What pitch prop?

 

[Dakota47]

Re: So Slow Drives Me Nuts

That Cat should be hitting the mid 40`s easy. maybe they are only 40hp each.

 

[JCF350]

Re: So Slow Drives Me Nuts

Weigh the boat also.
Don't remember exactly which length (pretty sure a 25') weighed 4200#

Most 26's are showing a cruise of 25-30kts with up to 39kts top (twin 150's).

 

[Drewmac]

Re: So Slow Drives Me Nuts

Interesting stuff...I thought I just needed a couple of Verado's...you know the ole no replacement for displacement scenerio! Sounds like there may be some other options though. I'm getting gear together more than driving, but I'm thinking we cruise (18-22) at around 26-28 rpms. Hammered down still only 25-28 on calm days or in the sound. Will the props have a number or angle on them. Waterlogged...is that common. How can I tell? Would weighing the boat give you that indication? Will try to get some transom pic's. Thanks for the replies!!!

 

[MikDee]

Re: So Slow Drives Me Nuts

It sounds like your boat weighs about the same as my old 24' Searay cuddy with the 350/260hp Mercruiser that would do 40mph,,, But you have a lot less wetted area in the middle with a cat, then a deep vee,,, lets check out those props, & engine height issues, so again what's your WOT rpm?

 

[dingbat]

Re: So Slow Drives Me Nuts

Interesting stuff...I thought I just needed a couple of Verado's...you know the ole no replacement for displacement scenerio! Sounds like there may be some other options though. I'm getting gear together more than driving, but I'm thinking we cruise (18-22) at around 26-28 rpms. Hammered down still only 25-28 on calm days or in the sound. Will the props have a number or angle on them. Waterlogged...is that common. How can I tell? Would weighing the boat give you that indication? Will try to get some transom pic's. Thanks for the replies!!!

Your numbers make no sense at all unless you have a spun prop. If 2600-2800RPM gives you 18-22 mph there is no way that twice the RPM is only giving you 7-10 mph more. That boat should run upper 30's at WOT

 

[Bigprairie1]

Re: So Slow Drives Me Nuts

You should give those motors a compression test to see if your power has been degraded due to low compression.
Ideally everything should be north of 110-120psi (140-150psi would be nice), anything below that might be showing up in lower performance.
Is the tune/timing all good? Due some checking on them.
I definitely agree with the other posts as well regarding the water logged foam/hull check.
Good luck and keep us posted.
BP

 

[tommays]

Re: So Slow Drives Me Nuts

could be me BUT i have yet to read that the motors are spinning up to the 5600 to 6200 RPM range they need to be reaching if there proped right