Carb adjustment for 35 HP lark

[55'Fleetwin7.5]

My 1957 Evinrude 35 Lark... I turned the low and high speed knobs and they only travel about 3/4 turns before hitting stops... Is this normal? This motor is new to me and I have not even started it yet... I have redone the ignition, seals and waterpump. Tomorrow I will attempt to fire it up to get a baseline. The cylinders are 118-119 each.

I never had a motor with auto choke capabilities and I believe this one does. Can you talk me through the steps for starting and tuning. It has the dash panel with the start and choke buttons. Thanks in advance.

I intend to rebiuld the carb too...

Thanks

 

[samo_ott]

Re: Carb adjustment for 35 HP lark

(Carburetor Adjustments - Two Adjustable N/Vs)
(J. Reeves)

Initial settings are: Bottom high speed = seat gently, then open 1 turn out. Top slow speed = seat gently, then open 1-1/2 turns.

Setting the high and low needle valves properly:

NOTE: For engines that DO NOT have a shift selection, obviously there is no NEUTRAL position. Simply lower the rpms to the lowest setting to obtain the low speed needle va /lve adjustment.

(High Speed) Start engine (it will run pretty rough), shift into forward gear, take up to full throttle. In segments of 1/8 turn, wating for the engine to respond between turns, start turning in the bottom high speed needle valve. You'll reach a point whereas the engine will either start to die out or spit back (sounds like a mild backfire). At that point, back out the needle valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest setting.

(Low Speed) Slow the engine down to where it just stays running. Shift into neutral. Again in segments of 1/8 turns, start to turn the top needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running. Eventually you'll hit the point where the engine wants to die out or it will spit back. Again, at that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

When you have finished the above adjustments, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

 

[jbjennings]

Re: Carb adjustment for 35 HP lark

If I could add anything, it'd be to say that yes, it is normal for them to hit a stop on the cowl. You have to either take the set screws out and pull the knob off and get it past the stop, or take them off and take the cowl off, then reattach them and adjust the carb with the cowl off so the adj. knobs don't hit the stops. then you can remove them, put the cowl back on, and put them back with the knob in the perfect position since you've already got it adjusted.
be careful that you don't seat the needle valves too hard or you'll ruin them. Be gentle....
JBJ

 

[F_R]

Re: Carb adjustment for 35 HP lark

It does not have an "automatic choke"....be glad! What it does have is an electric choke. Pushing and holding the button does the same exact thing as pulling the choke knob on the front of the motor.

To start the motor, prime (fill) the carburetor by pumping the button on top of the fuel tank till it gets hard to push down. Gas cap must be tight.

Shift to neutral. Now set the throttle toward fast as far as it will go in neutral gear. That is the correct start position.

Push and hold both the choke and start buttons. When motor fires, release buttons. If it starts but quits right away, try just the start button. If it starts and runs, but "sneezes" periodically, momentarilly "bump" the choke button to give it an extra shot of gas. Slow the motor down to a reasonable RPM. Don't rev it up in neutral.

High speed knob is to be set to where it runs the best at wide open throttle (On A Boat, In The Water, In Gear!!)
Same with the slow speed knob, but at idle throttle.

It ain't rocket science. Don't try to make it to be.

 

[55'Fleetwin7.5]

Re: Carb adjustment for 35 HP lark

Awesome FR! That was exactly what I needed...

For what it is worth, driving a car ain't rocket science either..but, I am glad my Dad showed me how the first time... It was in everyone's best interest.

Thanks again