Page 1 of 1

Weight concern, new engine, Offshore

Posted: Fri Oct 01, 2010 9:13 am
by PeterZ
Hello all
I am considering buying an Offshore I found recently, ... at least I think it is. Its approximately 1963-64, 19-20 foot Offshore, outboard, WI built. I will know more next week.

General question, I want too potentially put a new outboard on it but concerned about weight. I will be more than likely be rebuilding the boat - re-fastening, repairing-replacing ribs/strakes/transom etc. I don't want to do all this work to find out I can't exceed 250 lbs for a motor. I see there is a lot of discussion on HP for a given boat and some talk on weight, but not on whats too much weight. Has anyone powered any Thompson with a new 4-stroke 90Hp or up. I am assuming that I would have to consider at least this HP for this boat. The weights of Hondas and Yamahas are around 350-450 lbs (90hp and 115hp respectively) The Evinurude E-tec is not much lighter at the 90 HP level. Is this to much weight and should I only consider an older lighter motor - of which I am not interested in dealing with. Then the whole wood boat idea goes kinda goes out the window for me anyway. I have no idea how much those old 2 strokes weigh. Currently the boat has a late 1970's Johnson 140 hp on it.

thanks for any advice!!

Regards
Peter

Posted: Sat Oct 02, 2010 3:56 am
by LancerBoy
The 1963 Off-Shore (Peshtigo) is 20'-4" centerline length and rated for up to 160 HP. Weight capacity is 2,700 pounds.

The 1964 Off-Shore (Peshtigo) is 20'-1" centerline length and rated for up to 175 HP. Weight capacity rating is 2,700 pounds.

Weight of the various motors you are considering needs to be compared to weights of motors available in 1963-64. Also compared to the 1970s 140 HP currently on the boat.

www.old-omc.de has the brochures for Johnson and Evinrude. Most of them list wieghts for the various motors.

If weight becomes a problem, you may be able to beef up the transom and/or add braces from transom to keelson and stringers.

Andreas

Posted: Sat Oct 02, 2010 2:30 pm
by JoeCB
My 1961 75 hp Evinrude weighs 240 lbs. Seem to be no problem on the 17' (16-8) Sea Lancer and that's with an 18 gal gal tank and battery in the stern as well.
Joe B

Posted: Sun Oct 10, 2010 7:19 pm
by thegammas
My 1963 Merc 100Hp weighs 290 lbs, and that's without power tilt/trim. It's the original motor to my 1962 Cortland Sea Lancer. The e-tec 90 is 325 pounds. Not that much difference.

If you go with new power, go with a new 2-stroker. Lighter and much less to maintain than the 4 strokes. The new ones (say, 08 to present) are reported to be just as efficient and clean as the four strokes. They offer much more torque at the low end where you want the torque. But yeah,

If I could afford it, I' get me a 90 e-tec.

Engine weight

Posted: Wed Oct 13, 2010 5:29 pm
by PeterZ
Thanks Peter

My big concern would be the weight of the new 4 strokes on the wood transom. I was not too concerned with exceeding the weight of the allowed load in the boat. Thanks for your input. Since I am still boat-less, it is not too big of an issue right now. Keeping my eye out for a 19-20' off shore outboard.

Thanks
Regards
Peter