New Sea Pro Owner

[Deleted]

Hailing from the New Orleans area, I purchased my first boat 2 weeks ago
2001 Sea Pro 170CC w/ 90hp 2-stroke Yamaha
Motor runs strong , but I'm going to get the impeller changed out for good measure.

Only has the chance to take it out once since for fishing, but the boar did very well. I do have a couple of questions about the boa and it's performance.

At full throttle on flat water, she only gets to about 30mph when loaded with gear and 3 people - won't rev past 4300rpm. I think this boat had too much prop, but I don't know the specs on the stainless one that is on here. What size prop do I need??

She also tends to porpoise when wide open also. Back off the throttle a little and she's fine. - Anything I can do to help his?

Anything else you veteran boat owners can recommend would be great.

I'm going to enjoy being a member of these boards.

[Simple Man]

Welcome aboard f00mustang! Good to have you. I would think that boat would perform better than that with a 90 hp on it but I'll defer to the other 170CC owners for performance data.

[spikedaball]

welcome to the "family". Hope you haven't been adversely affected by the tropical storm.
I've got the same set up as you, but it's a 2002. The original prop that came with mine was a 13 1/4 x 17. Top speed is similar to what you mentioned, around 32 according to the boat's speedometer. Top rpm however, is a little higher. I get around 5000 if i push it. I don't have any problems with porpoising. I have the motor full tilt down to get it up on plane, then back off on the tilt a little and pick up a few more mph. Hope this helps!!

[Deleted]

Thanx for the welcomes.
@spiked - I'm ok with the speed, although getting to 40 as a top speed would be nicer. I really want it to get out of the hole better too. Im thinking of adding a fin to the motor and see if that helps.

As for the porpoising, maybe I'm trimming up to high once im on plane. I dont have a trim gauge. Hopefully the fins will help with that too.

The weather down here has really sucked. No damage, not even power loss, but a little street flooding. Just sucks that it's wiping out a three day weekend.

[cajunsauce]

Hey Mustang - A fellow Sea Pro owner from LA. I am up here and Prairieville. I am no expert at all, but maybe your speeds aren't that bad. I have a 1900 SV with a 130 Honda and a 17 inch prop. My one and only trip out was myself, wife and 4 kids and I could touch 40 gps in good water. She mostly ran real good around 35-37 gps. Keep in touch, let see what you find out.

[Deleted]

Welcome,

I have a S.P. SS1850 skiff with a 90 4 stroke on it. Your speed sounds about right with the load you had in the boat. RPM's seem a little low though. My boat will porpoise if I trim the motor up too much. I usually come out of the hole with it trimmed all the way down and then trim it up till it starts hopping and then bump it back down a touch or two. One of those stabilizer fins will help some too or to go even further, trim tabs maybe

[T-Topless]

The SeaPro 170cc and 180cc tend to porpoise a bit when loaded and 3/4 power (25-30mph).

You can trim the motor down a bit, but you lose speed.

Cheap/reliable solution is SmartTabs - I have them and love them. I have full trim stabs on my 26 and my 32' sportfish, but the simple SmartTabs work great on my 180cc ... even over 65mph!

[Deleted]

Thanks to all for the input. I do feel better that several people seem to see my top speed as accurate. A friend of mine gave me a stabilizer fin to throw on my Yamaha. I'm going to try out a freebie before I spend the money on tabs.

@ttoples - how did you put 200hp on that boat. I thought even the 19 was only rated for 150. I would love to put a new larger motor on mine down the road but I'm concerned about the weight if the new 4-strokes on this boat.

How are you guys dealing with the added weight of the newer engines on older boats?

[T-Topless]

I bought the boat new/used in 2000. The local dealer sold it new, but the owner decided (1 hour in the boat) he wanted the 90cc, so I snapped up the brand new hull (has a Suzuki 140 on it) and trailer at a bargain price, installed a jack plate and bought the ProV200 2-stroke from a friend in FL who was upgrading because the 200 only pushed his boat to 85mph (he added a pair of Mercury 3.0liter an got 130+mph - crazy).

It runs great - but did porpoise with the extra weight (and extended jack plate) until I added the Smart Tabs. The plate lets me ventilate the 23 Mirage prop when wide open and I've gotten 67mph on the GPS! Fun, but wild. I seldom run it wide open, but can run a little over 45mph at 4,000RPM to get down the ICW quickly to get to some of the better remote barrier island areas to fish. Surprising enough, this is pretty economical - not pushing a small motor hard.

I wouldn't go crazy on the 170cc - its a bit small to go crazy with power on. These deeper V, slab side, center console hulls are not bass or flats boats. What's your peak RPM? You might try a prop with 1-2" more pitc. You'll lose about 200rm for each inch of pitch you add, until you overload the motor and it won't even plane out. If you take the whole family out, tube, wakeboard or water ski, then leave it alone.

Yes - the heaver 4-stroke can be a problem on re-powers of older boats. Met a guy last week who had real issues when he went to the 4-stroke and now his boat constantly takes on water through the scuppers. He had to move batteries forward, etc. to try to alleviate the problem, and he can no longer stand in the back when sitting still.

[Weaverama]

If you still are not able to get those RPM's you may want to run a compression test. Don't want to sound any alarms but if all else fails there may be another problem. I am speaking from experience.

[Deleted]

Sept 8, 2011 5:40:27 GMT -6 Weaverama said:

If you still are not able to get those RPM's you may want to run a compression test. Don't want to sound any alarms but if all else fails there may be another problem. I am speaking from experience.

I had a very reputibal local Yamaha dealer check out the motor before I bought the boat. Compression checked ou just fine and he gave the moto a clean bill of health. Even old me I was getting a decent deal for he money I was paying for the setup.

Pretty sure this prop is just too much the boat when loaded down. I'm going to do some calm water runs and try a couple of remedies like the tabs or a fin.

[Deleted]

I put a sport 300 fin on my 210 WA and made a huge difference, planes twice as fast and steers alot better it does help with listing a little bit but nothing like a set of independant tabs would do. Also It stopped all porposing.

[CaptWoody]

Mustang, it sounds like our rigs are quite similar (mine is 2003). I live up on the NorthShore, have a lot to learn about my boat and fishing down south of NO.

[timmymac1990]

My 97 170cc with 90yammy will do 32 with the wife and I. If im by myself it will do 35

[fraydknot]

Mustang Welcome to the fourm

[985crabs]

I think maybe we should welcome Timmy. I think Mustang departed long ago as this thread is 8 years old.

Welcome Timmy.

[fraydknot]

ABSOLUTELY AGREED!!!!