1959 Sea Coaster-Motor HP/weight

Brad Rohloff · Post by **Brad Rohloff** » Mon Apr 05, 2010 7:03 am

I'm new to the Thompson boat ownership group. Have been looking for a good used newer outboard for the boat and wondering how big I can go. The tag on the boat says maximum 75 HP. I would like a 50 to 70 HP, 1990 or newer two stroke. I've found an Evinrude 60 HP, 1989 on Ebay, it weighs 250 #. Is this too much motor for the boat? The transom and entire boat has been restored and in very good condition.
Thanks!

LancerBoy · Post by **LancerBoy** » Mon Apr 05, 2010 2:04 pm

Probably just fine. A 1960 OMC 75 HP must weigh about 250#

Andreas

Brad Rohloff · Post by **Brad Rohloff** » Tue Apr 06, 2010 8:12 am

Thanks Andreas,
I've read that these boats can be somewhat sensitive to excess weight in the transom and didn't want to over do it. With the battery and fuel tank the transom weight could easily hit 300 lbs. I would like to be able to pull a skier with three people in the boat so the added HP will be helpfull.

W Guy · Post by **W Guy** » Tue Apr 06, 2010 6:29 pm

My '60 Sea Coaster is rated for a max of 70hp. You're '59 is 75hp???? Maybe they down-sized the '60??? Mine is 15' 10". My 50hp motor is 210# and the transom is low in the water.

Verne

LancerBoy · Post by **LancerBoy** » Wed Apr 07, 2010 3:17 am

Maybe the different Thompson boat firms had different ratings: Thompson Bros. Boat Mfg. Co. and Thompson Boat Company of New York, Inc.

Which firm made this boat?

Andreas

Brad Rohloff · Post by **Brad Rohloff** » Wed Apr 07, 2010 4:04 am

Good feed back. Mine is made in Pestigo, Wisc., that's what the metal tag on the back says, with maximum HP rated for 75. It certainly possible they reduced the maximum rating. The boat originally was 15'-10" to 16', can't tell exactly because I replaced the rotted gunwhale and it extended it in the front slightly. It's still no more than 16' though, beam is ~6' at the widest. Don't want to over power it, I could go with a 50 which would be lighter. Hopefully a fifty would get it on a plane without a problem.

W Guy · Post by **W Guy** » Wed Apr 07, 2010 6:11 am

Brad, My '60 with the 50hp gets on plane with no problem at all. That's with 3 people aboard, battery, 10gals of fuel and an anchor. I was even able to back off the throttle a bit and it stayed on plane.
Verne
PS: Mine is also a Peshtigo built boat. It's odd that they lowered the HP rating in '60....

JoeCB · Post by **JoeCB** » Wed Apr 07, 2010 3:25 pm

hello Brad, welcome aboard. My 1957 Sea Lancer ( 16' - 8" ) runs a 1961 75 HP evinrude, weight 240 lbs. with battery and 18 gal tank in the back.
Pulls a skier with 3 people in the boat, no problem. Planes fine at a little past half throttle.
I see that you are a neighbor... any questions e-mail me
fixerjo@sbcglobal.net

Joe B

Brad Rohloff · Post by **Brad Rohloff** » Thu Apr 08, 2010 3:47 am

Nice to know there's someone else in the neighborhood. Just digging up some info on the best size motor for my Sea Coaster. I'm finally close to having it ready for the water. Sounds like a 50 would be good and I probably wouldn't go smaller. The newer used Johson 60-70 HP may also work fine however, they both weigh more, closer to 250#.
One of the previous emails from Verne pointed to a reduction in max motor size from 75 to 70 the next model year from the manufacturer. I think the boat will handle the Hp just wondering about transom weight due to the boats size.
I have a picture taken this winter of the boat after I flipped it. The deck is only partially done. The deck on this boat looks different than any other I've seen on this web site, more enclosed near the transom than others.
Can anyone explain how to load a photo in this reply. I see the IMG tab but doesn't seem to work.
Brad

W Guy · Post by **W Guy** » Thu Apr 08, 2010 6:03 am

Brad, You need to set up a free account in a web based hosting service such as Photobucket. You upload photos from your computer onto the web account, then copy the image link from it, then paste it in the IMG box here when you make a post.

You say your transom is more enclosed. You may have what's known as a motor well, which may have been an option on the boat. Andreas should know more about that than I. Perhaps the motor well adds strength to the transom which allows for the higher HP rating??

Verne

Here's a photo of my transom area
[img][img]http://i83.photobucket.com/albums/j320/ ... 3_0002.jpg[/img][/img]

Brad Rohloff · Post by **Brad Rohloff** » Thu Apr 08, 2010 7:02 am

I'll set up the free account. Yes my boat has a section of deck that goes across in front of the motor. there are also doors that open to the motor well. i'l send photos as soon as I get things set up.
Brad

Brad Rohloff · Post by **Brad Rohloff** » Thu Apr 08, 2010 8:18 am

Here's the boat right after I flipped in in February '09. I've finished the deck sense then. You can see the framing for the portion of deck near the transom. I'll add more photos later.
brad

JoeCB · Post by **JoeCB** » Thu Apr 08, 2010 3:11 pm

Brad, WOW , she looks really nice. The framing around the motor well appears to be first class work. I 'm not sure that I've ever seen a Thompson with that type of well. Someone here ( AJR !) will know.
Look forward to racing you around Apple Island in Orchard Lake this spring.

Joe Brincat

W Guy · Post by **W Guy** » Thu Apr 08, 2010 6:12 pm

Brad, I agree with Joe. I've never seen any Sea Coaster with a motor well like that, or the decking forward of it. I also notice the high transom which will require a long lower unit on the motor.
I wish ajr would reply with his comments on the originality of that configuration. I Can't wait to see the finished version.

Brad Rohloff · Post by **Brad Rohloff** » Tue Apr 20, 2010 9:27 am

WGuy & JoeCB,
Piked up a '96 Johnson 50 HP over the weekend. I think it'll be a good size for the boat. Weighs in at 200#. I did measure the transom and it's 21-5/8', the long shaft motor is 20". I'm planning on triming the transome to ~20-1/2". Any thoughts? I've been told it needs to be within +/-1". Looking forward to that race around Apple Island Joe. By the way I picked up a bunch of Thompson hardware from the Guy I originally bought the boat from. Thompson name plates, spotlights, bow light etc. If anyone is looking for parts I may have it.
Brad