Starting an old 68 3HP

[gmkulak@hotmail.com]

Hi,<br />I have just gotten my hands on a JW-23A that appears to be in reasonable shape. It hasn't run in 15 + years. I'm a newbie so I need some help getting the thing going. It looks clean inside and the throttle / choke appears to be functiong normally. They are not gummed up as they say the motor was run out of fuel before being stuck in a corner for a couple of decades. Any help would be appreciated.<br /><br />Thanks

 

[Xcusme]

Re: Starting an old 68 3HP

Welcome to iboats! <br /><br />A motor that hasn't been run for that many years will have to be serviced before you attempt to run it. You should replace the water pump impeller and clean the carb. Drain and replace the lower unit lube. Pull the flywheel and check the ignition system (coils and points). You can do a compression test on both cylinders before you do anything to see what condition the rings are in. A service manual is a much needed item. <br /><br />Feel free to stop back in with any questions.

 

[Paul Moir]

Re: Starting an old 68 3HP

Welcome to Iboats!<br />Well, first start by checking spark. You should be able to draw at least a 1/4" long spark off each lead. Check them both. This is a common source of problems.<br />Next, if you have a compression checker then check your compression. This will give you an idea of the health of the engine. 5 good pulls for each test.<br />If all that works out, put a teaspoon of TC-W3 in each spark plug hole and turn the engine a couple times by hand. You should feel no rough spots, but you will feel a little play just after one of the pistons reaches full up.<br />Then put a 24:1 mix of 87 octane gas and TC-W3 rated outboard oil in the tank. Set the engine up so it's secured with water up to the seam betwen the lower unit and midsection (as it would be on a boat - I'll leave it to you to figure out how to rig it). Pull the choke knob (close the choke plate), set the throttle a little past 'START' and give the cord a few solid pulls and see if she fires. If it fires and quits, disengage the choke an pull a couple more times.<br />If it goes, pick up a service manual and tune it up. You will have to service the water pump impeller before running it for more than a couple seconds. The one that's in it is totally shot.<br /><br />Here's some good links:<br /> Tom's Excellent 3hp website.<br /> 3hp tune up page.<br /> Decarbing - You really want to do this if you get it running. <br /><br />Fuel Mix FAQ - the 3hp and later 4hp engine appreciate more oil than OMC recommended. <br />Great little engines, those! Tell us what you find!

 

[DJ]

Re: Starting an old 68 3HP

If it truly is a '68', it would use a fuel to oil ratio of 50:1.<br /><br />24:1 would not hurt, for a while.

 

[Paul Moir]

Re: Starting an old 68 3HP

DJ - on an engine that hasn't been run in 15 years, I think double oil is a good idea for the first tank.<br />Besides, until they redesigned the 4 into the 4.5hp in the 80s, they didn't have roller bearings anywhere but on the top crank (and not even that for the 3hp). And the old 3hp engines had oil slingers rather than seals on their top crank. I think Chinewalker covers this well in his FAQ.