Lark transom height

[doggunit]

My wood boat project specs are 20" transom, I have located a '59 Lark in great shape for the vintage look, but its a short shaft. How high can I mount this engine and not reasonably expect cavitation (boat is 19' semi-planing or semi-displacement depending on top speed).

 

[Dhadley]

Re: Lark transom height

Wouldnt it be better to convert the motor to a 20"?

 

[doggunit]

Re: Lark transom height

If I could find a long lower unit from a matching motor that would be a solution but I think the chances of finding one in good condition at a reasonable price would be difficult.

 

[Chris1956]

Re: Lark transom height

RC, Did the Evinrude Lark's of that era use a 5 inch extension kit? I know my '59 50HP motor did. The kit consisted of a five inch piece of copper pipe for the water intake, a five inch of pipe to cover the driveshaft, a five inch casting that bolted between the midsection and the lower unit, and a five inch longer driveshaft. The driveshaft simply pulled out of the lower unit, after you removed the water pump impeller. It is likely you could get this off a junk motor.

 

[Dhadley]

Re: Lark transom height

If you have the 35 hp model the kit is 377470 I believe.

 

[Chinewalker]

Re: Lark transom height

Hi R.C. ,<br /> The longshaft kits aren't all that hard to find, and the same kits were used on all the standard shift (non-electric) "fat" lower unit models from 1958 well into the 1960s, both Johnson and Evinrude. A little sleuthing at your local boatyards may turn up a whole parts motor for little dough. Longshafts were not uncommon in those days, and all you really need are the driveshaft, shift rod extension, water tube extensions (two), and the outer housing extension. Actually, the outer housing extension is the only part that is exclusive to the "fat" motors using the silencing housing. All the other parts are common to the other "Big Twin" models of the era from about 1955 to the late 1960s (non-electric shifting models) from Johnson, Evinrude, & Gale.<br /><br />If nothing turns up locally, try posting an ad on the AOMCI.org site's Webvertiser, and keep an eye on eBay, too.<br /><br />Good luck!<br />- Scott

 

[lark2004]

Re: Lark transom height

Measure your engine now, If i'm not mistaken, the short shaft engine is 18". The extension will put your gearcase well below the bottom a 20" transom.<br />Since you are building this wooden boat, It may be easier to lower the top of the transom 2".