40:1 or 24:1....?

[MTboatguy]

I am getting ready to fire my 1961 40hp Big Twin up and just wondered which mix I should go with? This motor has not been started in the last 9 months, so want to get it right and then fine tune from there...And yes, I used the search here, and I used the search on google, just double checking myself.

Thanks

 

[tx1961whaler]

Re: 40:1 or 24:1....?

It's really up to you. That motor was designed to run at 24:1, and I would run the first tank at that if it has been sitting for awhile. There is no real advantage to running it at 40:1, except for maybe spark plug fouling at extended trolling, more smoke, and possibly more internal carbon build up at 24:1. I don't boat as much these days, so I run full synthetic 2-cycle oil and that may mitigate most of these issues.

 

[MTboatguy]

Re: 40:1 or 24:1....?

Thank you, we will start our at 24:1 and see how it goes.

Thanks again.

 

[MTboatguy]

Re: 40:1 or 24:1....?

Well went with 24:1, stuck her in a 55 gallon barrel and she ran like a champ, I can't believe it, I can go lake fishing in the morning....YE HA!

 

[1946Zephyr]

Re: 40:1 or 24:1....?

Those old 40's are great engines. Run 'er at 24:1 religeously and she'll never fail you.

 

[mstahl1171]

Re: 40:1 or 24:1....?

Stick with 24:1 oil mix. My 62 runs its best with it. A little trick I do for trolling or extended slow speeds is carry a 3 gal tan with with 40:1 mix When we troll I switch over to that tank for slow speed and my plugs do not get fowled up. I also do a decarb at the beginning and end of each season and so far have had no problems with her. I just love these old motors...

 

[Sir Robin]

Re: 40:1 or 24:1....?

Follow mst's advice. Our '59 35hp "tiller" gets the same treatment, one pull.......
The small can to troll works well. One thought though... Replace float if have not already, The varnish is washed off by alcohol and they become "sinks"