1962 Evinrude Lark IV 40 hp issues

[Woodonglass]

Totally rebuilt her last winter. All new carb kits, mags, points, condensors, seals. EVERYTHING!!! Started on 2nd hit of the starter. Selectric Shift works perfect. First outing she ran GREAT for the first two hours. When we got to the bottom of the First tank she started coughing. Switched tanks and when she started she immediately went to WOT. Shut her down drained the Carbuerator Glass that had a bunch of Gunk in it and tried again Still went WOT. Was able to Start and Immedeately put in gear before she went WOT and limp back to dock. Do I need to tear down the carb again? Did gunk get in the jets? Where do I start?

Thanks.

 

[lindy46]

Re: 1962 Evinrude Lark IV 40 hp issues

What do you mean, "she went to WOT"? She's running away on you? Or is it more like the increase in RPM's when you run out of gas? Have you got a filter in the sediment bowl? If she's full of gunk, you need to clean out the tank, and possibly clean the carb again.

 

[kfa4303]

Re: 1962 Evinrude Lark IV 40 hp issues

+1. sounds like the carb is dirty. If you saw visible goo, that's more than enough to clog the tiny passages in the carb. I would take it off, give it a good cleaning with some aerosol cleaner and reinstall it. You should be able to reuse all the washers, etc... Be sure you clean out the fuel tanks too. They probably have some goo in the bottom as well. Just pour a bit of straight gas with some BBs, or marbles into the tank, shake it around and pour out the offending sludge; repeat as needed. You may want to inspect the fuel lines themselves too. Ethanol can degrade them overtime. The good news is that the Selectric shift work, which is the worst of it, and the fact that she runs at WOT means she's firing on both cylinders, so the spark and compression should be fine as well. Getting the carb dialed in is all just part of the sea trial process. This link may help too. Good luck. keep us posted.

http://www.outboard-boat-motor-repa...hnson 5.5 HP 1954-1964 Carburetor Tune-UP.htm

 

[1946Zephyr]

Re: 1962 Evinrude Lark IV 40 hp issues

On the front of the carb at the bottom, you will see a large plug. On earlier models, this is where the high speed jet would go. Remove that plug and drain it out into a rag. Then get a can of carb cleaner and poke the little red nozzle in there and flush it out. Once the carb cleaner all drains out, then prime it up again and see how well it'll start. You may have got water into your fuel and that's probably why it got gummed up inside. I would check and make sure the tank is completely cleaned out too.

 

[Woodonglass]

Re: 1962 Evinrude Lark IV 40 hp issues

I did the "Nuts and Bolts" cleaning on the tanks and rebuilt the internals including new pickup filters etc. I guess I did not have them as clean As I hoped. I dropped the Glass bulb on the carb and cleaned the small amount of gunk and the NEW filter inside the bulb was clear. I did forget to mention the Rich Lean adjustment needle valve on the front of the motor vibrated loose but I did reset it to it's original 3/4 turn setting as it was when the motor was running perfectly and retightened the brass nut. See pic...

It runs and idles perfectly while in gear, but on Start up will immediately go to WOT while the Throttle linkage is at Idle. Linkage is check and is at the idle position. Gunna put her in a barrel this weekend and see if I can figure it out. Thanks for Taking the time to check it out.

 

[kfa4303]

Re: 1962 Evinrude Lark IV 40 hp issues

glad you got it running, sorta. Not sure why it would go straight into WOT upon start up though. Perhaps the armature plate is out of alignment. I would run it in the test tank without controls, until you get it sorted out. The good news is that it starts and runs, which means the compression and spark are probably ok, which only leaves the fuel system to worry about. Good luck. Keep us posted.