Evinrude Lark V 40 HP Questions

[Bill1974]

Folks I just got a 40 HP Lark. It is mounted on a 1964 Starcraft 16 ft and I have a few questions.

I was told by the previous owner and the local Evinrude dealer that the oil ratio is 50:1. I see the manual calls for 24:1.
What is right? or is the modern fuel and oils just better?

The boat does not get up on a plane it creeps along at about 12-15 mph at full throttle from the helm? I am hoping it just needs a throttle adjustment. Would this be done from the shift box or on the engine? Engine does not sound like it is at max rpm 4500-5500 rpm. It has good compression with the hand pull start.

How do I adjust trim once I can this engine quirk ironed out?

Also engine has a rough idle and does not idle with the throttle at its stop.

 

[lindy46]

Re: Evinrude Lark V 40 HP Questions

Use 24:1 gas/oil mix. Sounds like you may be running on one cylinder. Check spark with a spark tester - both cylinders should jump at least 1/4" snappy blue-white spark. I'd also check compression with a gauge before dropping money into the motor. If compression is good, then I'd think about cleaning/rebuilding the carb to address the idle issue.

 

[Bill1974]

Re: Evinrude Lark V 40 HP Questions

I think I will just replace the ignition system from the coils down to the plugs. Just for a good peice of mind.

 

[F_R]

Re: Evinrude Lark V 40 HP Questions

1964 was the year that OMC came out with 50:1 TC-W oil oil. Your motor will be perfectly happy with todays version, TC-W3 at 50:1 It is much better oil than the old kind.

 

[Bill1974]

Re: Evinrude Lark V 40 HP Questions

I did look into the oil mix issue and found that I can run the 50:1 because I have roller bearings with the pistions with my model and that seams was the determining factor from switching from the 24:1 back the 60's plus the TC W3 oil.

I also found a bad plug on my eng and with 2 new plugs runs great. I was able to get the boat up to 26MPH with me solo.

My next little issue is the pin for holding up the engine while I am towing the boat (I am currently using a block of wood) I looked in the IPC and just can't figure it out with the poor pics. can I get a little help? So that I can order a new one

On another note I have found my transom to be bad and my buddy and I are going to replace it this July.

 

[lindy46]

Re: Evinrude Lark V 40 HP Questions

That motor is a 1963, and will probably be ok with the 50:1 ratio. As mentioned before, it was 1964 before they changed the ratio from 24:1 to 50:1. My personal opinion is to stick with the manufacturers recommendation, and I figure it can't hurt to run the mixture a little rich on 50+ year old motors.