Splashed the 72 Seafari - what I learned...

McGillicuddy · #1 10-27-2008, 04:15 AM

Finally spashed the Seafari.

I was apprehensive, but came out pleased. Never rode a SeaCraft before.

Gps says I got 15 mi on a 6 gal tank. Ran it in the bay doing laps 'til I burned thru the fuel. Topped out @ 33mph by GPS @ 4400 rpms.

Motor is an 83 Merc 115 I-6. Felt effortless, but I think I should be able to turn more rpms right? I thought I would get 5500 rpm or better but with the hammer down all I got was the 4400.

Rode well, if squirrely at times, in the wind chop - front end seemed to slide a bit running 33mph into the chop. Took a little water to the face and cap flew off but
not bad considering the wind chop. Trim tabs are definitely moving up on the shopping list.

Load was pretty light and I really don't know how much gas was in the tank but the ancient gas performed as well as the fresh for the 10 mi I ran on it...

Scuppers definitely let in a lot of water, certainly more than I expected. So that will need to be addressed, and the vortex system will also have to be employed. Steering (Rideglide) did not turn to port completely and kind of freaked me out at first as I had no control in the ramp basin. Changed the position of the pinion bolt (that's when I noticed the failings of the through hull scuppers)and went for it.

Trailer towed well, but needs some work. T-100 pulled it up a pretty steep ramp which I was concerned about.

Fishing partner was impressed by its rise to plane and described it as "nimble" for a 20' Oh yeah, he thought it rode nice...

Took it outside for a few runs into the choppy swell and it rode much better @ 25 knots than at 18-20 knots.

Overall I was pleased. Need to address the scuppers, steering and the balance of the originalrestoration list, but at least I'm confident it floats and runs.

Definitely needs a bow roller/pulpit. The anchoring setup is useless. Also if any one has some old Marinium cleats they aren't going to use I'd love to hear from you-lets make a deal...
Any feedback on the rpms? Propping, rigging?

--McGill

gofastsandman · #2 10-27-2008, 08:48 AM

Well done Gillie!
Check the throttle cable first as they strech over time. If the carbs are fully open, then thats good. Then hit the usual suspects. Should turn 5500 or better.
GFS

Bushwacker · #3 10-27-2008, 11:46 AM

Gillie - congratulations on a good shakedown run! What size prop are you running? Your max speed is comparable to what I got with my old V-4 115 running a 13 3/4 x 15 pitch prop @ 55-5600 rpm. Your rpm numbers are way off - I can't believe you'd get that kind of speed if you were really overpropped that badly, so I'd get that tach checked. The very first new tach I bought was off by about 500 rpm and led me to choose wrong prop. I think your gear ratio is also 2:1, so you should be running about same size prop. I averaged 2.8 mpg with my old 115 V-4 on the Bahama trips, most of it with very heavy load. It dropped to about 2 mpg when the power trim died!

Good observation on the better ride at 25 vs 20 mph! I didn't learn that till I made a 20 mile run in Abaco Sound from Green Turtle to Man-O-War Cay, straight into a 20 kt wind and 2' square waves! Check the Boating test article on the Seafari in the literature section, and you'll notice the running angle is flatter at 25 than at 20, which I believe explains the softer ride. The deadrise of that center panel is much higher a couple of feet aft of the bow than it is amidships, which is why I think trim and weight distribution is so important in the 20' hull! I concluded the ride would be even better if I could keep the boat running flat, but slow down and not hit 'em so hard! The trim tabs I installed for trip the following year were the best money I ever spent on that boat! They allowed me to plane at 12-15 mph and ride very comfortably SITTING DOWN in a 2-3' chop!

The key to easy anchoring is to keep the anchor chocked on deck or in a bow pulpit and use a big oval deck pipe to feed line into anchor locker. I was trying to conserve deck space and mounted deck pipe a little too far forward, so if I let out a lot of line, when retrieving I have to periodically reach down thru the deck pipe and shove the pile of line aft to keep it from blocking the opening. Would have been better if I had centered deck pipe over the anchor locker. Here's my anchor setup. Second shot shows how deck pipe is too far forward.
Denny

McGillicuddy · #4 10-27-2008, 09:02 PM

Thanks guys,

Denny, I'll read that Sseafari review again, Thanks for bringing it up.
Not sure of the prop, aluminum and likely a standard merc wheel - I'll have to get a prop spanner to get it off and have a look.

Re. anchor, I had a similar set-up on my 23' IMP and I was comfortable with that. I guess I'll get an anchor chock from BOW or somebody. get the roller later, well after the trim tabs. My current set-up came with a stanchion mount for the Al anchor but I found it annoying as much as anything.

Another thing - the shifter had some loose current giving me little shocks - any ideas where to look for that problem? Thanks.
-- Gillie

hermco · #5 10-28-2008, 10:15 AM

Quote:

Another thing - the shifter had some loose current giving me little shocks - any ideas where to look for that problem?

Engine trim switch has a power lead ...

McGillicuddy · #6 10-30-2008, 03:47 AM

Hermco, Thanks.
My understanding is that there are thee wires running from the toggle style trim switch -- 2 to a wire retainer and the 3rd brn/white to the trailer button then to the wire retainer before continuing to the key switch. Are you suggesting the problem lies in those first 2 contacts or in the brown and white wire that becomes a red wire on the way to the key switch. Any additional info would be great. Thanks - Gill

bridgeman · #7 10-30-2008, 08:33 PM

Reccommended rpm range for that I-6 115 hp merc is 4750-5250 what pitch prop are you running?

Briguy · #8 10-30-2008, 11:46 PM

Mc G, I have a stainless bow roller and 2 cleats. PM me and let me know if your interested. I can send pix after the weekend.

Fr. Frank · #9 10-31-2008, 11:53 AM

Quote:

Reccommended rpm range for that I-6 115 hp merc is 4750-5250 what pitch prop are you running?

My 1989 Mercury book says that '83-'88 Mercury/Mariner inline 6 115hp motors with AGI (non-distributer) ignition should run 4800 - 5500, the inline 6 90hp should run 4750 - 5250, and the inline 140 should run 5000 - 5800 rpms. It also suggests 4800 - 5400 for all Thunderbolt ignition inline 6 models from '77 - '83. I have owned and run more than a dozen inline 6 motors on recreational boats, and I set them all up to run 5700-5800 max rpms.

I used to race an inline 6 XS1500 150 and we turned 8000 rpms, and I've seen more than one turning close to 9K. But you absolutely do not want to run between 6200 and 6700 rpms as the harmonics will cause your motor to auto-destruct.

FTR, I heartily recommend either running 92 octane gas, or retarding the timing to 21 degree max advance.

bridgeman · #10 10-31-2008, 07:24 PM

They actually stayed together at that rpm? I'm no expert but if they did I'd say they're pretty much in-destructable. Makes me feel confident about the one I have on my starcraft. I've only run it for a year and it's never missed a beat 5100 rpm's at wot, smooth running motor.